Remi

crates/forth/src/compiler.rs

@@ -1,6 +1,6 @@
 use super::ops::Op;
 use super::types::{Dictionary, SourceSpan};
-use super::words::{compile_word, simple_op};
+use super::words::compile_word;
 
 #[derive(Clone, Debug)]
 enum Token {
@@ -8,8 +8,6 @@ enum Token {
     Float(f64, SourceSpan),
     Str(String, SourceSpan),
     Word(String, SourceSpan),
-    QuoteStart(usize),
-    QuoteEnd(usize),
 }
 
 pub(super) fn compile_script(input: &str, dict: &Dictionary) -> Result<Vec<Op>, String> {
@@ -27,6 +25,11 @@ fn tokenize(input: &str) -> Vec<Token> {
             continue;
         }
 
+        if c == '(' || c == ')' {
+            chars.next();
+            continue;
+        }
+
         if c == '"' {
             let start = pos;
             chars.next();
@@ -44,25 +47,21 @@ fn tokenize(input: &str) -> Vec<Token> {
             continue;
         }
 
-        if c == '(' {
-            while let Some(&(_, ch)) = chars.peek() {
-                chars.next();
-                if ch == ')' {
-                    break;
+        if c == ';' {
+            chars.next(); // consume first ;
+            if let Some(&(_, ';')) = chars.peek() {
+                // ;; starts a comment to end of line
+                chars.next(); // consume second ;
+                while let Some(&(_, ch)) = chars.peek() {
+                    if ch == '\n' {
+                        break;
+                    }
+                    chars.next();
                 }
+                continue;
             }
-            continue;
-        }
-
-        if c == '{' {
-            chars.next();
-            tokens.push(Token::QuoteStart(pos));
-            continue;
-        }
-
-        if c == '}' {
-            chars.next();
-            tokens.push(Token::QuoteEnd(pos));
+            // single ; is a word, create token
+            tokens.push(Token::Word(";".to_string(), SourceSpan { start: pos, end: pos + 1 }));
             continue;
         }
 
@@ -70,7 +69,7 @@ fn tokenize(input: &str) -> Vec<Token> {
         let mut word = String::new();
         let mut end = start;
         while let Some(&(i, ch)) = chars.peek() {
-            if ch.is_whitespace() || ch == '{' || ch == '}' {
+            if ch.is_whitespace() {
                 break;
             }
             end = i + ch.len_utf8();
@@ -94,25 +93,22 @@ fn tokenize(input: &str) -> Vec<Token> {
 fn compile(tokens: &[Token], dict: &Dictionary) -> Result<Vec<Op>, String> {
     let mut ops = Vec::new();
     let mut i = 0;
-    let mut list_depth: usize = 0;
 
     while i < tokens.len() {
         match &tokens[i] {
             Token::Int(n, span) => ops.push(Op::PushInt(*n, Some(*span))),
             Token::Float(f, span) => ops.push(Op::PushFloat(*f, Some(*span))),
             Token::Str(s, span) => ops.push(Op::PushStr(s.clone(), Some(*span))),
-            Token::QuoteStart(start_pos) => {
-                let (quote_ops, consumed, end_pos) = compile_quotation(&tokens[i + 1..], dict)?;
-                i += consumed;
-                let body_span = SourceSpan { start: *start_pos, end: end_pos + 1 };
-                ops.push(Op::Quotation(quote_ops, Some(body_span)));
-            }
-            Token::QuoteEnd(_) => {
-                return Err("unexpected }".into());
-            }
             Token::Word(w, span) => {
                 let word = w.as_str();
-                if word == ":" {
+                if word == "{" {
+                    let (quote_ops, consumed, end_span) = compile_quotation(&tokens[i + 1..], dict)?;
+                    i += consumed;
+                    let body_span = SourceSpan { start: span.start, end: end_span.end };
+                    ops.push(Op::Quotation(quote_ops, Some(body_span)));
+                } else if word == "}" {
+                    return Err("unexpected }".into());
+                } else if word == ":" {
                     let (consumed, name, body) = compile_colon_def(&tokens[i + 1..], dict)?;
                     i += consumed;
                     dict.lock().unwrap().insert(name, body);
@@ -130,20 +126,6 @@ fn compile(tokens: &[Token], dict: &Dictionary) -> Result<Vec<Op>, String> {
                         ops.push(Op::Branch(else_ops.len()));
                         ops.extend(else_ops);
                     }
-                } else if is_list_start(word) {
-                    ops.push(Op::ListStart);
-                    list_depth += 1;
-                } else if is_list_end(word) {
-                    list_depth = list_depth.saturating_sub(1);
-                    if let Some(op) = simple_op(word) {
-                        ops.push(op);
-                    }
-                } else if list_depth > 0 {
-                    let mut word_ops = Vec::new();
-                    if !compile_word(word, Some(*span), &mut word_ops, dict) {
-                        return Err(format!("unknown word: {word}"));
-                    }
-                    ops.push(Op::Quotation(word_ops, Some(*span)));
                 } else if !compile_word(word, Some(*span), &mut ops, dict) {
                     return Err(format!("unknown word: {word}"));
                 }
@@ -155,46 +137,38 @@ fn compile(tokens: &[Token], dict: &Dictionary) -> Result<Vec<Op>, String> {
     Ok(ops)
 }
 
-fn is_list_start(word: &str) -> bool {
-    matches!(word, "[" | "<" | "<<")
-}
-
-fn is_list_end(word: &str) -> bool {
-    matches!(word, "]" | ">" | ">>")
-}
-
-fn compile_quotation(tokens: &[Token], dict: &Dictionary) -> Result<(Vec<Op>, usize, usize), String> {
+fn compile_quotation(tokens: &[Token], dict: &Dictionary) -> Result<(Vec<Op>, usize, SourceSpan), String> {
     let mut depth = 1;
     let mut end_idx = None;
 
     for (i, tok) in tokens.iter().enumerate() {
-        match tok {
-            Token::QuoteStart(_) => depth += 1,
-            Token::QuoteEnd(_) => {
-                depth -= 1;
-                if depth == 0 {
-                    end_idx = Some(i);
-                    break;
+        if let Token::Word(w, _) = tok {
+            match w.as_str() {
+                "{" => depth += 1,
+                "}" => {
+                    depth -= 1;
+                    if depth == 0 {
+                        end_idx = Some(i);
+                        break;
+                    }
                 }
+                _ => {}
             }
-            _ => {}
         }
     }
 
     let end_idx = end_idx.ok_or("missing }")?;
-    let byte_pos = match &tokens[end_idx] {
-        Token::QuoteEnd(pos) => *pos,
+    let end_span = match &tokens[end_idx] {
+        Token::Word(_, span) => *span,
         _ => unreachable!(),
     };
     let quote_ops = compile(&tokens[..end_idx], dict)?;
-    Ok((quote_ops, end_idx + 1, byte_pos))
+    Ok((quote_ops, end_idx + 1, end_span))
 }
 
 fn token_span(tok: &Token) -> Option<SourceSpan> {
     match tok {
         Token::Int(_, s) | Token::Float(_, s) | Token::Str(_, s) | Token::Word(_, s) => Some(*s),
-        Token::QuoteStart(p) => Some(SourceSpan { start: *p, end: *p + 1 }),
-        Token::QuoteEnd(p) => Some(SourceSpan { start: *p, end: *p + 1 }),
     }
 }
 
@@ -218,7 +192,6 @@ fn compile_colon_def(tokens: &[Token], dict: &Dictionary) -> Result<(usize, Stri
     let semi_pos = semi_pos.ok_or("missing ';' in word definition")?;
     let body_tokens = &tokens[1..semi_pos];
     let body_ops = compile(body_tokens, dict)?;
-    // consumed = name + body + semicolon
     Ok((semi_pos + 1, name, body_ops))
 }
 

crates/forth/src/ops.rs

@@ -49,25 +49,20 @@ pub enum Op {
     NewCmd,
     SetParam(String),
     Emit,
-    Silence,
     Get,
     Set,
     GetContext(String),
     Rand,
     Seed,
     Cycle,
+    PCycle,
+    TCycle,
     Choose,
     ChanceExec,
     ProbExec,
     Coin,
     Mtof,
     Ftom,
-    ListStart,
-    ListEnd,
-    ListEndCycle,
-    PCycle,
-    ListEndPCycle,
-    Scale,
     SetTempo,
     Every,
     Quotation(Vec<Op>, Option<SourceSpan>),
@@ -84,10 +79,11 @@ pub enum Op {
     Loop,
     Degree(&'static [i64]),
     Oct,
-    DivStart,
-    DivEnd,
-    StackStart,
     EmitN,
     ClearCmd,
     SetSpeed,
+    At,
+    IntRange,
+    Generate,
+    GeomRange,
 }

crates/forth/src/types.rs

@@ -47,8 +47,8 @@ pub enum Value {
     Int(i64, Option<SourceSpan>),
     Float(f64, Option<SourceSpan>),
     Str(String, Option<SourceSpan>),
-    Marker,
     Quotation(Vec<Op>, Option<SourceSpan>),
+    CycleList(Vec<Value>),
 }
 
 impl PartialEq for Value {
@@ -57,8 +57,8 @@ impl PartialEq for Value {
             (Value::Int(a, _), Value::Int(b, _)) => a == b,
             (Value::Float(a, _), Value::Float(b, _)) => a == b,
             (Value::Str(a, _), Value::Str(b, _)) => a == b,
-            (Value::Marker, Value::Marker) => true,
             (Value::Quotation(a, _), Value::Quotation(b, _)) => a == b,
+            (Value::CycleList(a), Value::CycleList(b)) => a == b,
             _ => false,
         }
     }
@@ -93,29 +93,25 @@ impl Value {
             Value::Int(i, _) => *i != 0,
             Value::Float(f, _) => *f != 0.0,
             Value::Str(s, _) => !s.is_empty(),
-            Value::Marker => false,
             Value::Quotation(..) => true,
+            Value::CycleList(items) => !items.is_empty(),
         }
     }
 
-    pub(super) fn is_marker(&self) -> bool {
-        matches!(self, Value::Marker)
-    }
-
     pub(super) fn to_param_string(&self) -> String {
         match self {
             Value::Int(i, _) => i.to_string(),
             Value::Float(f, _) => f.to_string(),
             Value::Str(s, _) => s.clone(),
-            Value::Marker => String::new(),
             Value::Quotation(..) => String::new(),
+            Value::CycleList(_) => String::new(),
         }
     }
 
     pub(super) fn span(&self) -> Option<SourceSpan> {
         match self {
             Value::Int(_, s) | Value::Float(_, s) | Value::Str(_, s) | Value::Quotation(_, s) => *s,
-            Value::Marker => None,
+            Value::CycleList(_) => None,
         }
     }
 }
@@ -124,6 +120,7 @@ impl Value {
 pub(super) struct CmdRegister {
     sound: Option<Value>,
     params: Vec<(String, Value)>,
+    deltas: Vec<Value>,
 }
 
 impl CmdRegister {
@@ -135,10 +132,16 @@ impl CmdRegister {
         self.params.push((key, val));
     }
 
-    pub(super) fn snapshot(&self) -> Option<(Value, Vec<(String, Value)>)> {
-        self.sound
-            .as_ref()
-            .map(|s| (s.clone(), self.params.clone()))
+    pub(super) fn set_deltas(&mut self, deltas: Vec<Value>) {
+        self.deltas = deltas;
+    }
+
+    pub(super) fn deltas(&self) -> &[Value] {
+        &self.deltas
+    }
+
+    pub(super) fn snapshot(&self) -> Option<(&Value, &[(String, Value)])> {
+        self.sound.as_ref().map(|s| (s, self.params.as_slice()))
     }
 
     pub(super) fn clear(&mut self) {
@@ -147,54 +150,3 @@ impl CmdRegister {
     }
 }
 
-#[derive(Clone, Debug)]
-pub(super) struct PendingEmission {
-    pub sound: String,
-    pub params: Vec<(String, String)>,
-    pub slot_index: usize,
-}
-
-#[derive(Clone, Debug)]
-pub(super) struct ResolvedEmission {
-    pub sound: String,
-    pub params: Vec<(String, String)>,
-    pub parent_slot: usize,
-    pub offset_in_slot: f64,
-    pub dur: f64,
-}
-
-#[derive(Clone, Debug)]
-pub(super) struct ScopeContext {
-    pub start: f64,
-    pub duration: f64,
-    pub weight: f64,
-    pub slot_count: usize,
-    pub pending: Vec<PendingEmission>,
-    pub resolved: Vec<ResolvedEmission>,
-    pub stacked: bool,
-}
-
-impl ScopeContext {
-    pub fn new(start: f64, duration: f64) -> Self {
-        Self {
-            start,
-            duration,
-            weight: 1.0,
-            slot_count: 0,
-            pending: Vec::new(),
-            resolved: Vec::new(),
-            stacked: false,
-        }
-    }
-
-    pub fn claim_slot(&mut self) -> usize {
-        if self.stacked {
-            self.slot_count = 1;
-            0
-        } else {
-            let idx = self.slot_count;
-            self.slot_count += 1;
-            idx
-        }
-    }
-}

crates/forth/src/vm.rs

@@ -1,11 +1,11 @@
 use rand::rngs::StdRng;
 use rand::{Rng as RngTrait, SeedableRng};
+use std::borrow::Cow;
 
 use super::compiler::compile_script;
 use super::ops::Op;
 use super::types::{
-    CmdRegister, Dictionary, ExecutionTrace, PendingEmission, ResolvedEmission, Rng, ScopeContext,
-    Stack, StepContext, Value, Variables,
+    CmdRegister, Dictionary, ExecutionTrace, Rng, Stack, StepContext, Value, Variables,
 };
 
 pub struct Forth {
@@ -70,24 +70,9 @@ impl Forth {
     ) -> Result<Vec<String>, String> {
         let mut stack = self.stack.lock().unwrap();
         let mut outputs: Vec<String> = Vec::new();
-        let root_duration = ctx.step_duration() * 4.0;
-        let mut scope_stack: Vec<ScopeContext> = vec![ScopeContext::new(0.0, root_duration)];
         let mut cmd = CmdRegister::default();
 
-        self.execute_ops(
-            ops,
-            ctx,
-            &mut stack,
-            &mut outputs,
-            &mut scope_stack,
-            &mut cmd,
-            trace,
-        )?;
-
-        // Resolve root scope at end of script
-        if let Some(scope) = scope_stack.pop() {
-            resolve_scope(&scope, ctx.step_duration(), ctx.nudge_secs, &mut outputs);
-        }
+        self.execute_ops(ops, ctx, &mut stack, &mut outputs, &mut cmd, trace)?;
 
         Ok(outputs)
     }
@@ -100,70 +85,56 @@ impl Forth {
         ctx: &StepContext,
         stack: &mut Vec<Value>,
         outputs: &mut Vec<String>,
-        scope_stack: &mut Vec<ScopeContext>,
         cmd: &mut CmdRegister,
         trace: Option<&mut ExecutionTrace>,
     ) -> Result<(), String> {
         let mut pc = 0;
         let trace_cell = std::cell::RefCell::new(trace);
 
-        // Executes a quotation value, handling trace recording and recursive dispatch.
-        let run_quotation = |quot: Value,
-                             stack: &mut Vec<Value>,
-                             outputs: &mut Vec<String>,
-                             scope_stack: &mut Vec<ScopeContext>,
-                             cmd: &mut CmdRegister|
-         -> Result<(), String> {
-            match quot {
-                Value::Quotation(quot_ops, body_span) => {
-                    if let Some(span) = body_span {
-                        if let Some(trace) = trace_cell.borrow_mut().as_mut() {
-                            trace.executed_spans.push(span);
+        let run_quotation =
+            |quot: Value, stack: &mut Vec<Value>, outputs: &mut Vec<String>, cmd: &mut CmdRegister| -> Result<(), String> {
+                match quot {
+                    Value::Quotation(quot_ops, body_span) => {
+                        if let Some(span) = body_span {
+                            if let Some(trace) = trace_cell.borrow_mut().as_mut() {
+                                trace.executed_spans.push(span);
+                            }
                         }
+                        let mut trace_opt = trace_cell.borrow_mut().take();
+                        self.execute_ops(
+                            &quot_ops,
+                            ctx,
+                            stack,
+                            outputs,
+                            cmd,
+                            trace_opt.as_deref_mut(),
+                        )?;
+                        *trace_cell.borrow_mut() = trace_opt;
+                        Ok(())
                     }
-                    let mut trace_opt = trace_cell.borrow_mut().take();
-                    self.execute_ops(
-                        &quot_ops,
-                        ctx,
-                        stack,
-                        outputs,
-                        scope_stack,
-                        cmd,
-                        trace_opt.as_deref_mut(),
-                    )?;
-                    *trace_cell.borrow_mut() = trace_opt;
+                    _ => Err("expected quotation".into()),
+                }
+            };
+
+        let select_and_run =
+            |selected: Value, stack: &mut Vec<Value>, outputs: &mut Vec<String>, cmd: &mut CmdRegister| -> Result<(), String> {
+                if let Some(span) = selected.span() {
+                    if let Some(trace) = trace_cell.borrow_mut().as_mut() {
+                        trace.selected_spans.push(span);
+                    }
+                }
+                if matches!(selected, Value::Quotation(..)) {
+                    run_quotation(selected, stack, outputs, cmd)
+                } else {
+                    stack.push(selected);
                     Ok(())
                 }
-                _ => Err("expected quotation".into()),
-            }
-        };
+            };
 
-        // Selects a value from a list, records trace, and either executes (quotation) or pushes (other).
-        let select_and_run = |selected: Value,
-                              stack: &mut Vec<Value>,
-                              outputs: &mut Vec<String>,
-                              scope_stack: &mut Vec<ScopeContext>,
-                              cmd: &mut CmdRegister|
-         -> Result<(), String> {
-            if let Some(span) = selected.span() {
-                if let Some(trace) = trace_cell.borrow_mut().as_mut() {
-                    trace.selected_spans.push(span);
-                }
-            }
-            if matches!(selected, Value::Quotation(..)) {
-                run_quotation(selected, stack, outputs, scope_stack, cmd)
-            } else {
-                stack.push(selected);
-                Ok(())
-            }
-        };
-
-        // Drains `count` values from the stack, selects one by index, and runs it.
         let drain_select_run = |count: usize,
                                 idx: usize,
                                 stack: &mut Vec<Value>,
                                 outputs: &mut Vec<String>,
-                                scope_stack: &mut Vec<ScopeContext>,
                                 cmd: &mut CmdRegister|
          -> Result<(), String> {
             if stack.len() < count {
@@ -172,51 +143,27 @@ impl Forth {
             let start = stack.len() - count;
             let values: Vec<Value> = stack.drain(start..).collect();
             let selected = values[idx].clone();
-            select_and_run(selected, stack, outputs, scope_stack, cmd)
+            select_and_run(selected, stack, outputs, cmd)
         };
 
-        // Pops all values until a marker, selects one by index, and runs it.
-        let drain_list_select_run = |idx_source: usize,
-                                     err_msg: &str,
-                                     stack: &mut Vec<Value>,
-                                     outputs: &mut Vec<String>,
-                                     scope_stack: &mut Vec<ScopeContext>,
-                                     cmd: &mut CmdRegister|
-         -> Result<(), String> {
-            let mut values = Vec::new();
-            while let Some(v) = stack.pop() {
-                if v.is_marker() {
-                    break;
-                }
-                values.push(v);
-            }
-            if values.is_empty() {
-                return Err(err_msg.into());
-            }
-            values.reverse();
-            let idx = idx_source % values.len();
-            let selected = values[idx].clone();
-            select_and_run(selected, stack, outputs, scope_stack, cmd)
-        };
-
-        // Emits one sound event from the current command register into the current scope.
-        let emit_once = |cmd: &CmdRegister,
-                         scope_stack: &mut Vec<ScopeContext>|
-         -> Result<Option<Value>, String> {
+        let emit_with_cycling = |cmd: &CmdRegister, emit_idx: usize, delta_secs: f64, outputs: &mut Vec<String>| -> Result<Option<Value>, String> {
             let (sound_val, params) = cmd.snapshot().ok_or("no sound set")?;
-            let sound = sound_val.as_str()?.to_string();
-            let resolved_params: Vec<(String, String)> = params
-                .iter()
-                .map(|(k, v)| (k.clone(), v.to_param_string()))
-                .collect();
-            let scope = scope_stack.last_mut().ok_or("scope stack underflow")?;
-            let slot_idx = scope.claim_slot();
-            scope.pending.push(PendingEmission {
-                sound,
-                params: resolved_params,
-                slot_index: slot_idx,
-            });
-            Ok(Some(sound_val))
+            let resolved_sound_val = resolve_cycling(sound_val, emit_idx);
+            let sound = resolved_sound_val.as_str()?.to_string();
+            let resolved_params: Vec<(String, String)> =
+                params.iter().map(|(k, v)| {
+                    let resolved = resolve_cycling(v, emit_idx);
+                    if let Value::CycleList(_) = v {
+                        if let Some(span) = resolved.span() {
+                            if let Some(trace) = trace_cell.borrow_mut().as_mut() {
+                                trace.selected_spans.push(span);
+                            }
+                        }
+                    }
+                    (k.clone(), resolved.to_param_string())
+                }).collect();
+            emit_output(&sound, &resolved_params, ctx.step_duration(), delta_secs, outputs);
+            Ok(Some(resolved_sound_val.into_owned()))
         };
 
         while pc < ops.len() {
@@ -404,26 +351,31 @@ impl Forth {
                 }
 
                 Op::Emit => {
-                    if let Some(sound_val) = emit_once(cmd, scope_stack)? {
-                        if let Some(span) = sound_val.span() {
+                    let deltas = if cmd.deltas().is_empty() {
+                        vec![Value::Float(0.0, None)]
+                    } else {
+                        cmd.deltas().to_vec()
+                    };
+
+                    for (emit_idx, delta_val) in deltas.iter().enumerate() {
+                        let delta_frac = delta_val.as_float()?;
+                        let delta_secs = ctx.nudge_secs + delta_frac * ctx.step_duration();
+                        // Record delta span for highlighting
+                        if let Some(span) = delta_val.span() {
                             if let Some(trace) = trace_cell.borrow_mut().as_mut() {
                                 trace.selected_spans.push(span);
                             }
                         }
+                        if let Some(sound_val) = emit_with_cycling(cmd, emit_idx, delta_secs, outputs)? {
+                            if let Some(span) = sound_val.span() {
+                                if let Some(trace) = trace_cell.borrow_mut().as_mut() {
+                                    trace.selected_spans.push(span);
+                                }
+                            }
+                        }
                     }
                 }
 
-                Op::Silence => {
-                    let scope = scope_stack.last_mut().ok_or("scope stack underflow")?;
-                    scope.claim_slot();
-                }
-
-                Op::Scale => {
-                    let factor = stack.pop().ok_or("stack underflow")?.as_float()?;
-                    let scope = scope_stack.last_mut().ok_or("scope stack underflow")?;
-                    scope.weight = factor;
-                }
-
                 Op::Get => {
                     let name = stack.pop().ok_or("stack underflow")?;
                     let name = name.as_str()?;
@@ -489,7 +441,20 @@ impl Forth {
                         Op::Cycle => ctx.runs,
                         _ => ctx.iter,
                     } % count;
-                    drain_select_run(count, idx, stack, outputs, scope_stack, cmd)?;
+                    drain_select_run(count, idx, stack, outputs, cmd)?;
+                }
+
+                Op::TCycle => {
+                    let count = stack.pop().ok_or("stack underflow")?.as_int()? as usize;
+                    if count == 0 {
+                        return Err("tcycle count must be > 0".into());
+                    }
+                    if stack.len() < count {
+                        return Err("stack underflow".into());
+                    }
+                    let start = stack.len() - count;
+                    let values: Vec<Value> = stack.drain(start..).collect();
+                    stack.push(Value::CycleList(values));
                 }
 
                 Op::Choose => {
@@ -498,7 +463,7 @@ impl Forth {
                         return Err("choose count must be > 0".into());
                     }
                     let idx = self.rng.lock().unwrap().gen_range(0..count);
-                    drain_select_run(count, idx, stack, outputs, scope_stack, cmd)?;
+                    drain_select_run(count, idx, stack, outputs, cmd)?;
                 }
 
                 Op::ChanceExec | Op::ProbExec => {
@@ -510,7 +475,7 @@ impl Forth {
                         _ => threshold / 100.0,
                     };
                     if val < limit {
-                        run_quotation(quot, stack, outputs, scope_stack, cmd)?;
+                        run_quotation(quot, stack, outputs, cmd)?;
                     }
                 }
 
@@ -540,7 +505,7 @@ impl Forth {
                         _ => !cond.is_truthy(),
                     };
                     if should_run {
-                        run_quotation(quot, stack, outputs, scope_stack, cmd)?;
+                        run_quotation(quot, stack, outputs, cmd)?;
                     }
                 }
 
@@ -553,13 +518,13 @@ impl Forth {
                     } else {
                         false_quot
                     };
-                    run_quotation(quot, stack, outputs, scope_stack, cmd)?;
+                    run_quotation(quot, stack, outputs, cmd)?;
                 }
 
                 Op::Pick => {
                     let idx_i = stack.pop().ok_or("stack underflow")?.as_int()?;
                     if idx_i < 0 {
-                        return Err(format!("pick index must be >= 0, got {}", idx_i));
+                        return Err(format!("pick index must be >= 0, got {idx_i}"));
                     }
                     let idx = idx_i as usize;
                     let mut quots: Vec<Value> = Vec::new();
@@ -580,7 +545,7 @@ impl Forth {
                             quots.len()
                         ));
                     }
-                    run_quotation(quots.swap_remove(idx), stack, outputs, scope_stack, cmd)?;
+                    run_quotation(quots.swap_remove(idx), stack, outputs, cmd)?;
                 }
 
                 Op::Mtof => {
@@ -660,37 +625,29 @@ impl Forth {
                     cmd.set_param("dur".into(), Value::Float(dur, None));
                 }
 
-                Op::ListStart => {
-                    stack.push(Value::Marker);
-                }
-
-                Op::ListEnd => {
-                    let mut count = 0;
-                    let mut values = Vec::new();
-                    while let Some(v) = stack.pop() {
-                        if v.is_marker() {
-                            break;
+                Op::At => {
+                    let top = stack.pop().ok_or("stack underflow")?;
+                    let deltas = match &top {
+                        Value::Float(..) => vec![top],
+                        Value::Int(n, _) => {
+                            let count = *n as usize;
+                            if stack.len() < count {
+                                return Err(format!(
+                                    "at: stack underflow, expected {} values but got {}",
+                                    count,
+                                    stack.len()
+                                ));
+                            }
+                            let mut vals = Vec::with_capacity(count);
+                            for _ in 0..count {
+                                vals.push(stack.pop().ok_or("stack underflow")?);
+                            }
+                            vals.reverse();
+                            vals
                         }
-                        values.push(v);
-                        count += 1;
-                    }
-                    values.reverse();
-                    for v in values {
-                        stack.push(v);
-                    }
-                    stack.push(Value::Int(count, None));
-                }
-
-                Op::ListEndCycle | Op::ListEndPCycle => {
-                    let idx_source = match &ops[pc] {
-                        Op::ListEndCycle => ctx.runs,
-                        _ => ctx.iter,
+                        _ => return Err("at expects float or int count".into()),
                     };
-                    let err_msg = match &ops[pc] {
-                        Op::ListEndCycle => "empty cycle list",
-                        _ => "empty pattern cycle list",
-                    };
-                    drain_list_select_run(idx_source, err_msg, stack, outputs, scope_stack, cmd)?;
+                    cmd.set_deltas(deltas);
                 }
 
                 Op::Adsr => {
@@ -714,7 +671,7 @@ impl Forth {
 
                 Op::Apply => {
                     let quot = stack.pop().ok_or("stack underflow")?;
-                    run_quotation(quot, stack, outputs, scope_stack, cmd)?;
+                    run_quotation(quot, stack, outputs, cmd)?;
                 }
 
                 Op::Ramp => {
@@ -744,36 +701,6 @@ impl Forth {
                     stack.push(Value::Float(val, None));
                 }
 
-                Op::DivStart => {
-                    let parent = scope_stack.last().ok_or("scope stack underflow")?;
-                    let mut new_scope = ScopeContext::new(parent.start, parent.duration);
-                    new_scope.weight = parent.weight;
-                    scope_stack.push(new_scope);
-                }
-
-                Op::DivEnd => {
-                    if scope_stack.len() <= 1 {
-                        return Err("unmatched ~ (no div/stack to close)".into());
-                    }
-                    let child = scope_stack.pop().unwrap();
-
-                    if child.stacked {
-                        resolve_scope(&child, ctx.step_duration(), ctx.nudge_secs, outputs);
-                    } else {
-                        let parent = scope_stack.last_mut().ok_or("scope stack underflow")?;
-                        let parent_slot = parent.claim_slot();
-                        resolve_scope_to_parent(&child, parent_slot, parent);
-                    }
-                }
-
-                Op::StackStart => {
-                    let parent = scope_stack.last().ok_or("scope stack underflow")?;
-                    let mut new_scope = ScopeContext::new(parent.start, parent.duration);
-                    new_scope.weight = parent.weight;
-                    new_scope.stacked = true;
-                    scope_stack.push(new_scope);
-                }
-
                 Op::ClearCmd => {
                     cmd.clear();
                 }
@@ -783,8 +710,52 @@ impl Forth {
                     if n < 0 {
                         return Err("emit count must be >= 0".into());
                     }
-                    for _ in 0..n {
-                        emit_once(cmd, scope_stack)?;
+                    for i in 0..n as usize {
+                        emit_with_cycling(cmd, i, ctx.nudge_secs, outputs)?;
+                    }
+                }
+
+                Op::IntRange => {
+                    let end = stack.pop().ok_or("stack underflow")?.as_int()?;
+                    let start = stack.pop().ok_or("stack underflow")?.as_int()?;
+                    if start <= end {
+                        for i in start..=end {
+                            stack.push(Value::Int(i, None));
+                        }
+                    } else {
+                        for i in (end..=start).rev() {
+                            stack.push(Value::Int(i, None));
+                        }
+                    }
+                }
+
+                Op::Generate => {
+                    let count = stack.pop().ok_or("stack underflow")?.as_int()?;
+                    let quot = stack.pop().ok_or("stack underflow")?;
+                    if count < 0 {
+                        return Err("gen count must be >= 0".into());
+                    }
+                    let mut results = Vec::with_capacity(count as usize);
+                    for _ in 0..count {
+                        run_quotation(quot.clone(), stack, outputs, cmd)?;
+                        results.push(stack.pop().ok_or("gen: quotation must produce a value")?);
+                    }
+                    for val in results {
+                        stack.push(val);
+                    }
+                }
+
+                Op::GeomRange => {
+                    let count = stack.pop().ok_or("stack underflow")?.as_int()?;
+                    let ratio = stack.pop().ok_or("stack underflow")?.as_float()?;
+                    let start = stack.pop().ok_or("stack underflow")?.as_float()?;
+                    if count < 0 {
+                        return Err("geom.. count must be >= 0".into());
+                    }
+                    let mut val = start;
+                    for _ in 0..count {
+                        stack.push(float_to_value(val));
+                        val *= ratio;
                     }
                 }
             }
@@ -795,158 +766,58 @@ impl Forth {
     }
 }
 
-fn resolve_scope(
-    scope: &ScopeContext,
-    step_duration: f64,
-    nudge_secs: f64,
-    outputs: &mut Vec<String>,
-) {
-    let slot_dur = if scope.slot_count == 0 {
-        scope.duration * scope.weight
-    } else {
-        scope.duration * scope.weight / scope.slot_count as f64
-    };
-
-    struct Emission {
-        delta: f64,
-        sound: String,
-        params: Vec<(String, String)>,
-        dur: f64,
-    }
-
-    let mut emissions: Vec<Emission> = Vec::new();
-
-    for em in &scope.pending {
-        let delta = scope.start + slot_dur * em.slot_index as f64;
-        emissions.push(Emission {
-            delta,
-            sound: em.sound.clone(),
-            params: em.params.clone(),
-            dur: slot_dur,
-        });
-    }
-
-    for em in &scope.resolved {
-        let slot_start = slot_dur * em.parent_slot as f64;
-        let delta = scope.start + slot_start + em.offset_in_slot * slot_dur;
-        let dur = em.dur * slot_dur;
-        emissions.push(Emission {
-            delta,
-            sound: em.sound.clone(),
-            params: em.params.clone(),
-            dur,
-        });
-    }
-
-    emissions.sort_by(|a, b| {
-        a.delta
-            .partial_cmp(&b.delta)
-            .unwrap_or(std::cmp::Ordering::Equal)
-    });
-
-    for em in emissions {
-        emit_output(
-            &em.sound,
-            &em.params,
-            em.delta,
-            em.dur,
-            step_duration,
-            nudge_secs,
-            outputs,
-        );
-    }
+fn is_tempo_scaled_param(name: &str) -> bool {
+    matches!(
+        name,
+        "attack"
+            | "decay"
+            | "release"
+            | "lpa"
+            | "lpd"
+            | "lpr"
+            | "hpa"
+            | "hpd"
+            | "hpr"
+            | "bpa"
+            | "bpd"
+            | "bpr"
+            | "patt"
+            | "pdec"
+            | "prel"
+            | "fma"
+            | "fmd"
+            | "fmr"
+            | "glide"
+            | "verbdecay"
+            | "verbpredelay"
+            | "chorusdelay"
+            | "duration"
+    )
 }
 
-fn resolve_scope_to_parent(child: &ScopeContext, parent_slot: usize, parent: &mut ScopeContext) {
-    if child.slot_count == 0 && child.pending.is_empty() && child.resolved.is_empty() {
-        return;
-    }
-
-    let child_slot_count = child.slot_count.max(1);
-
-    // Store offsets and durations as fractions of the parent slot
-    // Child's internal structure: slot_count slots, each slot is 1/slot_count of the whole
-    for em in &child.pending {
-        let offset_fraction = em.slot_index as f64 / child_slot_count as f64;
-        let dur_fraction = 1.0 / child_slot_count as f64;
-        parent.resolved.push(ResolvedEmission {
-            sound: em.sound.clone(),
-            params: em.params.clone(),
-            parent_slot,
-            offset_in_slot: offset_fraction,
-            dur: dur_fraction,
-        });
-    }
-
-    // Child's resolved emissions already have fractional offsets/durs relative to their slots
-    // We need to compose them: em belongs to child slot em.parent_slot, which is a fraction of child
-    for em in &child.resolved {
-        let child_slot_offset = em.parent_slot as f64 / child_slot_count as f64;
-        let child_slot_size = 1.0 / child_slot_count as f64;
-        let offset_fraction = child_slot_offset + em.offset_in_slot * child_slot_size;
-        let dur_fraction = em.dur * child_slot_size;
-        parent.resolved.push(ResolvedEmission {
-            sound: em.sound.clone(),
-            params: em.params.clone(),
-            parent_slot,
-            offset_in_slot: offset_fraction,
-            dur: dur_fraction,
-        });
-    }
-}
-
-const TEMPO_SCALED_PARAMS: &[&str] = &[
-    "attack",
-    "decay",
-    "release",
-    "lpa",
-    "lpd",
-    "lpr",
-    "hpa",
-    "hpd",
-    "hpr",
-    "bpa",
-    "bpd",
-    "bpr",
-    "patt",
-    "pdec",
-    "prel",
-    "fma",
-    "fmd",
-    "fmr",
-    "glide",
-    "verbdecay",
-    "verbpredelay",
-    "chorusdelay",
-    "duration",
-];
-
 fn emit_output(
     sound: &str,
     params: &[(String, String)],
-    delta: f64,
-    dur: f64,
     step_duration: f64,
     nudge_secs: f64,
     outputs: &mut Vec<String>,
 ) {
-    let nudged_delta = delta + nudge_secs;
     let mut pairs = vec![("sound".into(), sound.to_string())];
     pairs.extend(params.iter().cloned());
-    if nudged_delta > 0.0 {
-        pairs.push(("delta".into(), nudged_delta.to_string()));
+    if nudge_secs > 0.0 {
+        pairs.push(("delta".into(), nudge_secs.to_string()));
     }
     if !pairs.iter().any(|(k, _)| k == "dur") {
-        pairs.push(("dur".into(), dur.to_string()));
+        pairs.push(("dur".into(), step_duration.to_string()));
     }
     if let Some(idx) = pairs.iter().position(|(k, _)| k == "delaytime") {
         let ratio: f64 = pairs[idx].1.parse().unwrap_or(1.0);
-        pairs[idx].1 = (ratio * dur).to_string();
+        pairs[idx].1 = (ratio * step_duration).to_string();
     } else {
-        pairs.push(("delaytime".into(), dur.to_string()));
+        pairs.push(("delaytime".into(), step_duration.to_string()));
     }
     for pair in &mut pairs {
-        if TEMPO_SCALED_PARAMS.contains(&pair.0.as_str()) {
+        if is_tempo_scaled_param(&pair.0) {
             if let Ok(val) = pair.1.parse::<f64>() {
                 pair.1 = (val * step_duration).to_string();
             }
@@ -1033,3 +904,12 @@ fn format_cmd(pairs: &[(String, String)]) -> String {
     let parts: Vec<String> = pairs.iter().map(|(k, v)| format!("{k}/{v}")).collect();
     format!("/{}", parts.join("/"))
 }
+
+fn resolve_cycling(val: &Value, emit_idx: usize) -> Cow<'_, Value> {
+    match val {
+        Value::CycleList(items) if !items.is_empty() => {
+            Cow::Owned(items[emit_idx % items.len()].clone())
+        }
+        other => Cow::Borrowed(other),
+    }
+}

crates/ratatui/src/scope.rs

@@ -2,6 +2,11 @@ use ratatui::buffer::Buffer;
 use ratatui::layout::Rect;
 use ratatui::style::Color;
 use ratatui::widgets::Widget;
+use std::cell::RefCell;
+
+thread_local! {
+    static PATTERNS: RefCell<Vec<u8>> = const { RefCell::new(Vec::new()) };
+}
 
 #[allow(dead_code)]
 pub enum Orientation {
@@ -58,46 +63,51 @@ fn render_horizontal(data: &[f32], area: Rect, buf: &mut Buffer, color: Color, g
     let fine_width = width * 2;
     let fine_height = height * 4;
 
-    let mut patterns = vec![0u8; width * height];
+    PATTERNS.with(|p| {
+        let mut patterns = p.borrow_mut();
+        let size = width * height;
+        patterns.clear();
+        patterns.resize(size, 0);
 
-    for fine_x in 0..fine_width {
-        let sample_idx = (fine_x * data.len()) / fine_width;
-        let sample = (data.get(sample_idx).copied().unwrap_or(0.0) * gain).clamp(-1.0, 1.0);
+        for fine_x in 0..fine_width {
+            let sample_idx = (fine_x * data.len()) / fine_width;
+            let sample = (data.get(sample_idx).copied().unwrap_or(0.0) * gain).clamp(-1.0, 1.0);
 
-        let fine_y = ((1.0 - sample) * 0.5 * (fine_height - 1) as f32).round() as usize;
-        let fine_y = fine_y.min(fine_height - 1);
+            let fine_y = ((1.0 - sample) * 0.5 * (fine_height - 1) as f32).round() as usize;
+            let fine_y = fine_y.min(fine_height - 1);
 
-        let char_x = fine_x / 2;
-        let char_y = fine_y / 4;
-        let dot_x = fine_x % 2;
-        let dot_y = fine_y % 4;
+            let char_x = fine_x / 2;
+            let char_y = fine_y / 4;
+            let dot_x = fine_x % 2;
+            let dot_y = fine_y % 4;
 
-        let bit = match (dot_x, dot_y) {
-            (0, 0) => 0x01,
-            (0, 1) => 0x02,
-            (0, 2) => 0x04,
-            (0, 3) => 0x40,
-            (1, 0) => 0x08,
-            (1, 1) => 0x10,
-            (1, 2) => 0x20,
-            (1, 3) => 0x80,
-            _ => unreachable!(),
-        };
+            let bit = match (dot_x, dot_y) {
+                (0, 0) => 0x01,
+                (0, 1) => 0x02,
+                (0, 2) => 0x04,
+                (0, 3) => 0x40,
+                (1, 0) => 0x08,
+                (1, 1) => 0x10,
+                (1, 2) => 0x20,
+                (1, 3) => 0x80,
+                _ => unreachable!(),
+            };
 
-        patterns[char_y * width + char_x] |= bit;
-    }
+            patterns[char_y * width + char_x] |= bit;
+        }
 
-    for cy in 0..height {
-        for cx in 0..width {
-            let pattern = patterns[cy * width + cx];
-            if pattern != 0 {
-                let ch = char::from_u32(0x2800 + pattern as u32).unwrap_or(' ');
-                buf[(area.x + cx as u16, area.y + cy as u16)]
-                    .set_char(ch)
-                    .set_fg(color);
+        for cy in 0..height {
+            for cx in 0..width {
+                let pattern = patterns[cy * width + cx];
+                if pattern != 0 {
+                    let ch = char::from_u32(0x2800 + pattern as u32).unwrap_or(' ');
+                    buf[(area.x + cx as u16, area.y + cy as u16)]
+                        .set_char(ch)
+                        .set_fg(color);
+                }
             }
         }
-    }
+    });
 }
 
 fn render_vertical(data: &[f32], area: Rect, buf: &mut Buffer, color: Color, gain: f32) {
@@ -106,44 +116,49 @@ fn render_vertical(data: &[f32], area: Rect, buf: &mut Buffer, color: Color, gai
     let fine_width = width * 2;
     let fine_height = height * 4;
 
-    let mut patterns = vec![0u8; width * height];
+    PATTERNS.with(|p| {
+        let mut patterns = p.borrow_mut();
+        let size = width * height;
+        patterns.clear();
+        patterns.resize(size, 0);
 
-    for fine_y in 0..fine_height {
-        let sample_idx = (fine_y * data.len()) / fine_height;
-        let sample = (data.get(sample_idx).copied().unwrap_or(0.0) * gain).clamp(-1.0, 1.0);
+        for fine_y in 0..fine_height {
+            let sample_idx = (fine_y * data.len()) / fine_height;
+            let sample = (data.get(sample_idx).copied().unwrap_or(0.0) * gain).clamp(-1.0, 1.0);
 
-        let fine_x = ((sample + 1.0) * 0.5 * (fine_width - 1) as f32).round() as usize;
-        let fine_x = fine_x.min(fine_width - 1);
+            let fine_x = ((sample + 1.0) * 0.5 * (fine_width - 1) as f32).round() as usize;
+            let fine_x = fine_x.min(fine_width - 1);
 
-        let char_x = fine_x / 2;
-        let char_y = fine_y / 4;
-        let dot_x = fine_x % 2;
-        let dot_y = fine_y % 4;
+            let char_x = fine_x / 2;
+            let char_y = fine_y / 4;
+            let dot_x = fine_x % 2;
+            let dot_y = fine_y % 4;
 
-        let bit = match (dot_x, dot_y) {
-            (0, 0) => 0x01,
-            (0, 1) => 0x02,
-            (0, 2) => 0x04,
-            (0, 3) => 0x40,
-            (1, 0) => 0x08,
-            (1, 1) => 0x10,
-            (1, 2) => 0x20,
-            (1, 3) => 0x80,
-            _ => unreachable!(),
-        };
+            let bit = match (dot_x, dot_y) {
+                (0, 0) => 0x01,
+                (0, 1) => 0x02,
+                (0, 2) => 0x04,
+                (0, 3) => 0x40,
+                (1, 0) => 0x08,
+                (1, 1) => 0x10,
+                (1, 2) => 0x20,
+                (1, 3) => 0x80,
+                _ => unreachable!(),
+            };
 
-        patterns[char_y * width + char_x] |= bit;
-    }
+            patterns[char_y * width + char_x] |= bit;
+        }
 
-    for cy in 0..height {
-        for cx in 0..width {
-            let pattern = patterns[cy * width + cx];
-            if pattern != 0 {
-                let ch = char::from_u32(0x2800 + pattern as u32).unwrap_or(' ');
-                buf[(area.x + cx as u16, area.y + cy as u16)]
-                    .set_char(ch)
-                    .set_fg(color);
+        for cy in 0..height {
+            for cx in 0..width {
+                let pattern = patterns[cy * width + cx];
+                if pattern != 0 {
+                    let ch = char::from_u32(0x2800 + pattern as u32).unwrap_or(' ');
+                    buf[(area.x + cx as u16, area.y + cy as u16)]
+                        .set_char(ch)
+                        .set_fg(color);
+                }
             }
         }
-    }
+    });
 }

src/engine/audio.rs

@@ -85,6 +85,7 @@ struct SpectrumAnalyzer {
     fft: Arc<dyn rustfft::Fft<f32>>,
     window: [f32; FFT_SIZE],
     scratch: Vec<Complex<f32>>,
+    fft_buf: Vec<Complex<f32>>,
     band_edges: [usize; NUM_BANDS + 1],
 }
 
@@ -114,6 +115,7 @@ impl SpectrumAnalyzer {
             fft,
             window,
             scratch: vec![Complex::default(); scratch_len],
+            fft_buf: vec![Complex::default(); FFT_SIZE],
             band_edges,
         }
     }
@@ -130,20 +132,19 @@ impl SpectrumAnalyzer {
     }
 
     fn run_fft(&mut self, output: &SpectrumBuffer) {
-        let mut buf: Vec<Complex<f32>> = (0..FFT_SIZE)
-            .map(|i| {
-                let idx = (self.pos + i) % FFT_SIZE;
-                Complex::new(self.ring[idx] * self.window[i], 0.0)
-            })
-            .collect();
+        for i in 0..FFT_SIZE {
+            let idx = (self.pos + i) % FFT_SIZE;
+            self.fft_buf[i] = Complex::new(self.ring[idx] * self.window[i], 0.0);
+        }
 
-        self.fft.process_with_scratch(&mut buf, &mut self.scratch);
+        self.fft
+            .process_with_scratch(&mut self.fft_buf, &mut self.scratch);
 
         let mut bands = [0.0f32; NUM_BANDS];
         for (band, mag) in bands.iter_mut().enumerate() {
             let lo = self.band_edges[band];
             let hi = self.band_edges[band + 1].max(lo + 1);
-            let sum: f32 = buf[lo..hi].iter().map(|c| c.norm()).sum();
+            let sum: f32 = self.fft_buf[lo..hi].iter().map(|c| c.norm()).sum();
             let avg = sum / (hi - lo) as f32;
             let amplitude = avg / (FFT_SIZE as f32 / 2.0);
             let db = 20.0 * amplitude.max(1e-10).log10();

src/engine/sequencer.rs

@@ -93,17 +93,19 @@ pub struct ActivePatternState {
     pub iter: usize,
 }
 
+pub type StepTracesMap = HashMap<(usize, usize, usize), ExecutionTrace>;
+
 #[derive(Clone, Default)]
 pub struct SharedSequencerState {
     pub active_patterns: Vec<ActivePatternState>,
-    pub step_traces: HashMap<(usize, usize, usize), ExecutionTrace>,
+    pub step_traces: Arc<StepTracesMap>,
     pub event_count: usize,
     pub dropped_events: usize,
 }
 
 pub struct SequencerSnapshot {
     pub active_patterns: Vec<ActivePatternState>,
-    pub step_traces: HashMap<(usize, usize, usize), ExecutionTrace>,
+    step_traces: Arc<StepTracesMap>,
     pub event_count: usize,
     pub dropped_events: usize,
 }
@@ -146,7 +148,7 @@ impl SequencerHandle {
         let state = self.shared_state.load();
         SequencerSnapshot {
             active_patterns: state.active_patterns.clone(),
-            step_traces: state.step_traces.clone(),
+            step_traces: Arc::clone(&state.step_traces),
             event_count: state.event_count,
             dropped_events: state.dropped_events,
         }
@@ -197,6 +199,7 @@ impl AudioState {
     }
 }
 
+#[allow(clippy::too_many_arguments)]
 pub fn spawn_sequencer(
     link: Arc<LinkState>,
     playing: Arc<std::sync::atomic::AtomicBool>,
@@ -365,7 +368,6 @@ pub(crate) struct TickOutput {
 }
 
 struct StepResult {
-    audio_commands: Vec<String>,
     completed_iterations: Vec<PatternId>,
     any_step_fired: bool,
 }
@@ -383,15 +385,44 @@ fn parse_chain_target(s: &str) -> Option<PatternId> {
     })
 }
 
+struct KeyCache {
+    speed_keys: [[String; MAX_PATTERNS]; MAX_BANKS],
+    chain_keys: [[String; MAX_PATTERNS]; MAX_BANKS],
+}
+
+impl KeyCache {
+    fn new() -> Self {
+        Self {
+            speed_keys: std::array::from_fn(|bank| {
+                std::array::from_fn(|pattern| format!("__speed_{bank}_{pattern}__"))
+            }),
+            chain_keys: std::array::from_fn(|bank| {
+                std::array::from_fn(|pattern| format!("__chain_{bank}_{pattern}__"))
+            }),
+        }
+    }
+
+    fn speed_key(&self, bank: usize, pattern: usize) -> &str {
+        &self.speed_keys[bank][pattern]
+    }
+
+    fn chain_key(&self, bank: usize, pattern: usize) -> &str {
+        &self.chain_keys[bank][pattern]
+    }
+}
+
 pub(crate) struct SequencerState {
     audio_state: AudioState,
     pattern_cache: PatternCache,
     runs_counter: RunsCounter,
-    step_traces: HashMap<(usize, usize, usize), ExecutionTrace>,
+    step_traces: Arc<StepTracesMap>,
     event_count: usize,
     dropped_events: usize,
     script_engine: ScriptEngine,
     variables: Variables,
+    speed_overrides: HashMap<(usize, usize), f64>,
+    key_cache: KeyCache,
+    buf_audio_commands: Vec<String>,
 }
 
 impl SequencerState {
@@ -405,11 +436,14 @@ impl SequencerState {
             audio_state: AudioState::new(),
             pattern_cache: PatternCache::new(),
             runs_counter: RunsCounter::new(),
-            step_traces: HashMap::new(),
+            step_traces: Arc::new(HashMap::new()),
             event_count: 0,
             dropped_events: 0,
             script_engine,
             variables,
+            speed_overrides: HashMap::new(),
+            key_cache: KeyCache::new(),
+            buf_audio_commands: Vec::new(),
         }
     }
 
@@ -458,7 +492,7 @@ impl SequencerState {
                     self.audio_state.active_patterns.clear();
                     self.audio_state.pending_starts.clear();
                     self.audio_state.pending_stops.clear();
-                    self.step_traces.clear();
+                    Arc::make_mut(&mut self.step_traces).clear();
                     self.runs_counter.counts.clear();
                 }
                 SeqCommand::Shutdown => {}
@@ -490,7 +524,7 @@ impl SequencerState {
         self.audio_state.prev_beat = beat;
 
         TickOutput {
-            audio_commands: steps.audio_commands,
+            audio_commands: std::mem::take(&mut self.buf_audio_commands),
             new_tempo: vars.new_tempo,
             shared_state: self.build_shared_state(),
         }
@@ -499,13 +533,15 @@ impl SequencerState {
     fn tick_paused(&mut self) -> TickOutput {
         for pending in self.audio_state.pending_stops.drain(..) {
             self.audio_state.active_patterns.remove(&pending.id);
-            self.step_traces.retain(|&(bank, pattern, _), _| {
+            Arc::make_mut(&mut self.step_traces).retain(|&(bank, pattern, _), _| {
                 bank != pending.id.bank || pattern != pending.id.pattern
             });
         }
         self.audio_state.pending_starts.clear();
+        self.audio_state.prev_beat = -1.0;
+        self.buf_audio_commands.clear();
         TickOutput {
-            audio_commands: Vec::new(),
+            audio_commands: std::mem::take(&mut self.buf_audio_commands),
             new_tempo: None,
             shared_state: self.build_shared_state(),
         }
@@ -546,7 +582,7 @@ impl SequencerState {
         for pending in &self.audio_state.pending_stops {
             if check_quantization_boundary(pending.quantization, beat, prev_beat, quantum) {
                 self.audio_state.active_patterns.remove(&pending.id);
-                self.step_traces.retain(|&(bank, pattern, _), _| {
+                Arc::make_mut(&mut self.step_traces).retain(|&(bank, pattern, _), _| {
                     bank != pending.id.bank || pattern != pending.id.pattern
                 });
                 stopped.push(pending.id);
@@ -564,32 +600,29 @@ impl SequencerState {
         fill: bool,
         nudge_secs: f64,
     ) -> StepResult {
+        self.buf_audio_commands.clear();
         let mut result = StepResult {
-            audio_commands: Vec::new(),
             completed_iterations: Vec::new(),
             any_step_fired: false,
         };
 
-        let speed_overrides: HashMap<(usize, usize), f64> = {
+        self.speed_overrides.clear();
+        {
             let vars = self.variables.lock().unwrap();
-            self.audio_state
-                .active_patterns
-                .keys()
-                .filter_map(|id| {
-                    let key = format!("__speed_{}_{}__", id.bank, id.pattern);
-                    vars.get(&key)
-                        .and_then(|v| v.as_float().ok())
-                        .map(|v| ((id.bank, id.pattern), v))
-                })
-                .collect()
-        };
+            for id in self.audio_state.active_patterns.keys() {
+                let key = self.key_cache.speed_key(id.bank, id.pattern);
+                if let Some(v) = vars.get(key).and_then(|v| v.as_float().ok()) {
+                    self.speed_overrides.insert((id.bank, id.pattern), v);
+                }
+            }
+        }
 
         for (_id, active) in self.audio_state.active_patterns.iter_mut() {
             let Some(pattern) = self.pattern_cache.get(active.bank, active.pattern) else {
                 continue;
             };
 
-            let speed_mult = speed_overrides
+            let speed_mult = self.speed_overrides
                 .get(&(active.bank, active.pattern))
                 .copied()
                 .unwrap_or_else(|| pattern.speed.multiplier());
@@ -633,13 +666,13 @@ impl SequencerState {
                                 .script_engine
                                 .evaluate_with_trace(script, &ctx, &mut trace)
                             {
-                                self.step_traces.insert(
+                                Arc::make_mut(&mut self.step_traces).insert(
                                     (active.bank, active.pattern, source_idx),
                                     std::mem::take(&mut trace),
                                 );
                                 for cmd in cmds {
                                     self.event_count += 1;
-                                    result.audio_commands.push(cmd);
+                                    self.buf_audio_commands.push(cmd);
                                 }
                             }
                         }
@@ -680,18 +713,18 @@ impl SequencerState {
 
         let mut chain_transitions = Vec::new();
         for id in completed {
-            let chain_key = format!("__chain_{}_{}__", id.bank, id.pattern);
-            if let Some(Value::Str(s, _)) = vars.get(&chain_key) {
+            let chain_key = self.key_cache.chain_key(id.bank, id.pattern);
+            if let Some(Value::Str(s, _)) = vars.get(chain_key) {
                 if let Some(target) = parse_chain_target(s) {
                     chain_transitions.push((*id, target));
                 }
             }
-            vars.remove(&chain_key);
+            vars.remove(chain_key);
         }
 
         for id in stopped {
-            let chain_key = format!("__chain_{}_{}__", id.bank, id.pattern);
-            vars.remove(&chain_key);
+            let chain_key = self.key_cache.chain_key(id.bank, id.pattern);
+            vars.remove(chain_key);
         }
 
         VariableReads {
@@ -737,7 +770,7 @@ impl SequencerState {
                     iter: a.iter,
                 })
                 .collect(),
-            step_traces: self.step_traces.clone(),
+            step_traces: Arc::clone(&self.step_traces),
             event_count: self.event_count,
             dropped_events: self.dropped_events,
         }

src/input.rs

@@ -476,6 +476,9 @@ fn handle_modal_input(ctx: &mut InputContext, key: KeyEvent) -> InputResult {
                 KeyCode::Char('p') if ctrl => {
                     editor.search_prev();
                 }
+                KeyCode::Char('s') if ctrl => {
+                    ctx.app.editor_ctx.show_stack = !ctx.app.editor_ctx.show_stack;
+                }
                 KeyCode::Char('a') if ctrl => {
                     editor.select_all();
                 }
@@ -890,7 +893,11 @@ fn handle_patterns_page(ctx: &mut InputContext, key: KeyEvent) -> InputResult {
             }
         }
         KeyCode::Enter => ctx.dispatch(AppCommand::PatternsEnter),
-        KeyCode::Char(' ') => ctx.dispatch(AppCommand::PatternsTogglePlay),
+        KeyCode::Char(' ') => {
+            if ctx.app.patterns_nav.column == PatternsColumn::Patterns {
+                ctx.dispatch(AppCommand::PatternsTogglePlay);
+            }
+        }
         KeyCode::Char('c') if !ctrl => ctx.dispatch(AppCommand::CommitStagedChanges),
         KeyCode::Char('q') => {
             ctx.dispatch(AppCommand::OpenModal(Modal::ConfirmQuit {

src/state/editor.rs

@@ -1,3 +1,4 @@
+use std::cell::RefCell;
 use std::ops::RangeInclusive;
 
 use cagire_ratatui::Editor;
@@ -54,6 +55,15 @@ pub struct EditorContext {
     pub editor: Editor,
     pub selection_anchor: Option<usize>,
     pub copied_steps: Option<CopiedSteps>,
+    pub show_stack: bool,
+    pub stack_cache: RefCell<Option<StackCache>>,
+}
+
+#[derive(Clone)]
+pub struct StackCache {
+    pub cursor_line: usize,
+    pub lines_hash: u64,
+    pub result: String,
 }
 
 #[derive(Clone)]
@@ -94,6 +104,8 @@ impl Default for EditorContext {
             editor: Editor::new(),
             selection_anchor: None,
             copied_steps: None,
+            show_stack: false,
+            stack_cache: RefCell::new(None),
         }
     }
 }

src/state/mod.rs

@@ -13,7 +13,7 @@ pub mod ui;
 
 pub use audio::{AudioSettings, DeviceKind, EngineSection, Metrics, SettingKind};
 pub use options::{OptionsFocus, OptionsState};
-pub use editor::{CopiedStepData, CopiedSteps, EditorContext, Focus, PatternField, PatternPropsField};
+pub use editor::{CopiedStepData, CopiedSteps, EditorContext, Focus, PatternField, PatternPropsField, StackCache};
 pub use live_keys::LiveKeyState;
 pub use modal::Modal;
 pub use panel::{PanelFocus, PanelState, SidePanel};

src/views/engine_view.rs

@@ -187,6 +187,7 @@ fn render_devices(frame: &mut Frame, app: &App, area: Rect) {
     );
 }
 
+#[allow(clippy::too_many_arguments)]
 fn render_device_column(
     frame: &mut Frame,
     area: Rect,

src/views/help_view.rs

@@ -242,7 +242,7 @@ fn parse_markdown(md: &str) -> Vec<RLine<'static>> {
         match line {
             Line::Normal(composite) if composite.style == CompositeStyle::Code => {
                 code_line_nr += 1;
-                let raw: String = composite.compounds.iter().map(|c| &*c.src).collect();
+                let raw: String = composite.compounds.iter().map(|c: &minimad::Compound| c.src).collect();
                 let mut spans = vec![
                     Span::styled(format!(" {code_line_nr:>2} "), code_border_style()),
                     Span::styled("│ ", code_border_style()),

src/views/highlight.rs

@@ -16,39 +16,90 @@ pub enum TokenKind {
     Note,
     Interval,
     Variable,
+    Emit,
+    Vary,
+    Generator,
     Default,
 }
 
 impl TokenKind {
     pub fn style(self) -> Style {
         match self {
-            TokenKind::Number => Style::default().fg(Color::Rgb(255, 180, 100)),
-            TokenKind::String => Style::default().fg(Color::Rgb(150, 220, 150)),
-            TokenKind::Comment => Style::default().fg(Color::Rgb(100, 100, 100)),
-            TokenKind::Keyword => Style::default().fg(Color::Rgb(220, 120, 220)),
-            TokenKind::StackOp => Style::default().fg(Color::Rgb(120, 180, 220)),
-            TokenKind::Operator => Style::default().fg(Color::Rgb(200, 200, 130)),
-            TokenKind::Sound => Style::default().fg(Color::Rgb(100, 220, 200)),
-            TokenKind::Param => Style::default().fg(Color::Rgb(180, 150, 220)),
-            TokenKind::Context => Style::default().fg(Color::Rgb(220, 180, 120)),
-            TokenKind::Note => Style::default().fg(Color::Rgb(120, 200, 160)),
-            TokenKind::Interval => Style::default().fg(Color::Rgb(160, 200, 120)),
-            TokenKind::Variable => Style::default().fg(Color::Rgb(200, 140, 180)),
-            TokenKind::Default => Style::default().fg(Color::Rgb(200, 200, 200)),
+            TokenKind::Emit => Style::default()
+                .fg(Color::Rgb(255, 255, 255))
+                .bg(Color::Rgb(140, 50, 50))
+                .add_modifier(Modifier::BOLD),
+            TokenKind::Number => Style::default()
+                .fg(Color::Rgb(255, 200, 120))
+                .bg(Color::Rgb(60, 40, 15)),
+            TokenKind::String => Style::default()
+                .fg(Color::Rgb(150, 230, 150))
+                .bg(Color::Rgb(20, 55, 20)),
+            TokenKind::Comment => Style::default()
+                .fg(Color::Rgb(100, 100, 100))
+                .bg(Color::Rgb(18, 18, 18)),
+            TokenKind::Keyword => Style::default()
+                .fg(Color::Rgb(230, 130, 230))
+                .bg(Color::Rgb(55, 25, 55)),
+            TokenKind::StackOp => Style::default()
+                .fg(Color::Rgb(130, 190, 240))
+                .bg(Color::Rgb(20, 40, 70)),
+            TokenKind::Operator => Style::default()
+                .fg(Color::Rgb(220, 220, 140))
+                .bg(Color::Rgb(45, 45, 20)),
+            TokenKind::Sound => Style::default()
+                .fg(Color::Rgb(100, 240, 220))
+                .bg(Color::Rgb(15, 60, 55)),
+            TokenKind::Param => Style::default()
+                .fg(Color::Rgb(190, 160, 240))
+                .bg(Color::Rgb(45, 30, 70)),
+            TokenKind::Context => Style::default()
+                .fg(Color::Rgb(240, 190, 120))
+                .bg(Color::Rgb(60, 45, 20)),
+            TokenKind::Note => Style::default()
+                .fg(Color::Rgb(120, 220, 170))
+                .bg(Color::Rgb(20, 55, 40)),
+            TokenKind::Interval => Style::default()
+                .fg(Color::Rgb(170, 220, 120))
+                .bg(Color::Rgb(35, 55, 20)),
+            TokenKind::Variable => Style::default()
+                .fg(Color::Rgb(220, 150, 190))
+                .bg(Color::Rgb(60, 30, 50)),
+            TokenKind::Vary => Style::default()
+                .fg(Color::Rgb(230, 230, 100))
+                .bg(Color::Rgb(55, 55, 15)),
+            TokenKind::Generator => Style::default()
+                .fg(Color::Rgb(100, 220, 180))
+                .bg(Color::Rgb(15, 55, 45)),
+            TokenKind::Default => Style::default()
+                .fg(Color::Rgb(160, 160, 160))
+                .bg(Color::Rgb(25, 25, 25)),
         }
     }
+
+    pub fn gap_style() -> Style {
+        Style::default().bg(Color::Rgb(25, 25, 25))
+    }
 }
 
 pub struct Token {
     pub start: usize,
     pub end: usize,
     pub kind: TokenKind,
+    pub varargs: bool,
 }
 
-fn lookup_word_kind(word: &str) -> Option<TokenKind> {
+fn lookup_word_kind(word: &str) -> Option<(TokenKind, bool)> {
+    if word == "." {
+        return Some((TokenKind::Emit, false));
+    }
+    if word == ".!" {
+        return Some((TokenKind::Emit, true));
+    }
+
     for w in WORDS {
         if w.name == word || w.aliases.contains(&word) {
-            return Some(match &w.compile {
+            let kind = match &w.compile {
                 WordCompile::Param => TokenKind::Param,
                 WordCompile::Context(_) => TokenKind::Context,
                 _ => match w.category {
@@ -58,9 +109,12 @@ fn lookup_word_kind(word: &str) -> Option<TokenKind> {
                         TokenKind::Operator
                     }
                     "Sound" => TokenKind::Sound,
+                    "Randomness" | "Probability" | "Selection" => TokenKind::Vary,
+                    "Generator" => TokenKind::Generator,
                     _ => TokenKind::Keyword,
                 },
-            });
+            };
+            return Some((kind, w.varargs));
         }
     }
     None
@@ -97,24 +151,14 @@ pub fn tokenize_line(line: &str) -> Vec<Token> {
             continue;
         }
 
-        if c == '(' {
-            let end = line.len();
-            let comment_end = line[start..]
-                .find(')')
-                .map(|i| start + i + 1)
-                .unwrap_or(end);
+        if c == ';' && chars.peek().map(|(_, ch)| *ch) == Some(';') {
             tokens.push(Token {
                 start,
-                end: comment_end,
+                end: line.len(),
                 kind: TokenKind::Comment,
+                varargs: false,
             });
-            while let Some((i, _)) = chars.peek() {
-                if *i >= comment_end {
-                    break;
-                }
-                chars.next();
-            }
-            continue;
+            break;
         }
 
         if c == '"' {
@@ -129,6 +173,7 @@ pub fn tokenize_line(line: &str) -> Vec<Token> {
                 start,
                 end,
                 kind: TokenKind::String,
+                varargs: false,
             });
             continue;
         }
@@ -143,35 +188,35 @@ pub fn tokenize_line(line: &str) -> Vec<Token> {
         }
 
         let word = &line[start..end];
-        let kind = classify_word(word);
-        tokens.push(Token { start, end, kind });
+        let (kind, varargs) = classify_word(word);
+        tokens.push(Token { start, end, kind, varargs });
     }
 
     tokens
 }
 
-fn classify_word(word: &str) -> TokenKind {
+fn classify_word(word: &str) -> (TokenKind, bool) {
     if word.parse::<f64>().is_ok() || word.parse::<i64>().is_ok() {
-        return TokenKind::Number;
+        return (TokenKind::Number, false);
     }
 
-    if let Some(kind) = lookup_word_kind(word) {
-        return kind;
+    if let Some((kind, varargs)) = lookup_word_kind(word) {
+        return (kind, varargs);
     }
 
     if INTERVALS.contains(&word) {
-        return TokenKind::Interval;
+        return (TokenKind::Interval, false);
     }
 
     if is_note(&word.to_ascii_lowercase()) {
-        return TokenKind::Note;
+        return (TokenKind::Note, false);
     }
 
     if word.len() > 1 && (word.starts_with('@') || word.starts_with('!')) {
-        return TokenKind::Variable;
+        return (TokenKind::Variable, false);
     }
 
-    TokenKind::Default
+    (TokenKind::Default, false)
 }
 
 pub fn highlight_line(line: &str) -> Vec<(Style, String)> {
@@ -189,13 +234,11 @@ pub fn highlight_line_with_runtime(
 
     let executed_bg = Color::Rgb(40, 35, 50);
     let selected_bg = Color::Rgb(80, 60, 20);
+    let gap_style = TokenKind::gap_style();
 
     for token in tokens {
         if token.start > last_end {
-            result.push((
-                TokenKind::Default.style(),
-                line[last_end..token.start].to_string(),
-            ));
+            result.push((gap_style, line[last_end..token.start].to_string()));
         }
 
         let is_selected = selected_spans
@@ -206,6 +249,9 @@ pub fn highlight_line_with_runtime(
             .any(|span| overlaps(token.start, token.end, span.start, span.end));
 
         let mut style = token.kind.style();
+        if token.varargs {
+            style = style.add_modifier(Modifier::UNDERLINED);
+        }
         if is_selected {
             style = style.bg(selected_bg).add_modifier(Modifier::BOLD);
         } else if is_executed {
@@ -217,7 +263,7 @@ pub fn highlight_line_with_runtime(
     }
 
     if last_end < line.len() {
-        result.push((TokenKind::Default.style(), line[last_end..].to_string()));
+        result.push((gap_style, line[last_end..].to_string()));
     }
 
     result

src/views/render.rs

@@ -1,16 +1,23 @@
+use std::collections::hash_map::DefaultHasher;
+use std::collections::HashMap;
+use std::hash::{Hash, Hasher};
+use std::sync::{Arc, Mutex};
 use std::time::Instant;
 
+use rand::rngs::StdRng;
+use rand::SeedableRng;
 use ratatui::layout::{Alignment, Constraint, Layout, Rect};
 use ratatui::style::{Color, Modifier, Style};
 use ratatui::text::{Line, Span};
 use ratatui::widgets::{Block, Borders, Cell, Clear, Paragraph, Row, Table};
 use ratatui::Frame;
 
+use cagire_forth::Forth;
 use crate::app::App;
 use crate::engine::{LinkState, SequencerSnapshot};
-use crate::model::SourceSpan;
+use crate::model::{SourceSpan, StepContext, Value};
 use crate::page::Page;
-use crate::state::{FlashKind, Modal, PanelFocus, PatternField, SidePanel};
+use crate::state::{FlashKind, Modal, PanelFocus, PatternField, SidePanel, StackCache};
 use crate::views::highlight::{self, highlight_line, highlight_line_with_runtime};
 use crate::widgets::{
     ConfirmModal, ModalFrame, NavMinimap, NavTile, SampleBrowser, TextInputModal,
@@ -20,6 +27,88 @@ use super::{
     dict_view, engine_view, help_view, main_view, options_view, patterns_view, title_view,
 };
 
+fn compute_stack_display(lines: &[String], editor: &cagire_ratatui::Editor, cache: &std::cell::RefCell<Option<StackCache>>) -> String {
+    let cursor_line = editor.cursor().0;
+
+    let mut hasher = DefaultHasher::new();
+    for (i, line) in lines.iter().enumerate() {
+        if i > cursor_line {
+            break;
+        }
+        line.hash(&mut hasher);
+    }
+    let lines_hash = hasher.finish();
+
+    if let Some(ref c) = *cache.borrow() {
+        if c.cursor_line == cursor_line && c.lines_hash == lines_hash {
+            return c.result.clone();
+        }
+    }
+
+    let partial: Vec<&str> = lines.iter().take(cursor_line + 1).map(|s| s.as_str()).collect();
+    let script = partial.join("\n");
+
+    let result = if script.trim().is_empty() {
+        "Stack: []".to_string()
+    } else {
+        let vars = Arc::new(Mutex::new(HashMap::new()));
+        let dict = Arc::new(Mutex::new(HashMap::new()));
+        let rng = Arc::new(Mutex::new(StdRng::seed_from_u64(42)));
+        let forth = Forth::new(vars, dict, rng);
+
+        let ctx = StepContext {
+            step: 0,
+            beat: 0.0,
+            bank: 0,
+            pattern: 0,
+            tempo: 120.0,
+            phase: 0.0,
+            slot: 0,
+            runs: 0,
+            iter: 0,
+            speed: 1.0,
+            fill: false,
+            nudge_secs: 0.0,
+        };
+
+        match forth.evaluate(&script, &ctx) {
+            Ok(_) => {
+                let stack = forth.stack();
+                let formatted: Vec<String> = stack.iter().map(format_value).collect();
+                format!("Stack: [{}]", formatted.join(" "))
+            }
+            Err(e) => format!("Error: {e}"),
+        }
+    };
+
+    *cache.borrow_mut() = Some(StackCache {
+        cursor_line,
+        lines_hash,
+        result: result.clone(),
+    });
+
+    result
+}
+
+fn format_value(v: &Value) -> String {
+    match v {
+        Value::Int(n, _) => n.to_string(),
+        Value::Float(f, _) => {
+            if f.fract() == 0.0 && f.abs() < 1_000_000.0 {
+                format!("{f:.1}")
+            } else {
+                format!("{f:.4}")
+            }
+        }
+        Value::Str(s, _) => format!("\"{s}\""),
+        Value::Quotation(..) => "[...]".to_string(),
+        Value::CycleList(items) => {
+            let inner: Vec<String> = items.iter().map(format_value).collect();
+            format!("({})", inner.join(" "))
+        }
+    }
+}
+
 fn adjust_spans_for_line(
     spans: &[SourceSpan],
     line_start: usize,
@@ -69,7 +158,7 @@ pub fn render(frame: &mut Frame, app: &App, link: &LinkState, snapshot: &Sequenc
     };
 
     let [header_area, _padding, body_area, _bottom_padding, footer_area] = Layout::vertical([
-        Constraint::Length(1),
+        Constraint::Length(header_height(padded.width)),
         Constraint::Length(1),
         Constraint::Fill(1),
         Constraint::Length(1),
@@ -136,6 +225,10 @@ pub fn render(frame: &mut Frame, app: &App, link: &LinkState, snapshot: &Sequenc
     }
 }
 
+fn header_height(width: u16) -> u16 {
+    if width >= 80 { 1 } else { 2 }
+}
+
 fn render_side_panel(frame: &mut Frame, app: &App, area: Rect) {
     let focused = app.panel.focus == PanelFocus::Side;
     match &app.panel.side {
@@ -163,17 +256,41 @@ fn render_header(
     let bank = &app.project_state.project.banks[app.editor_ctx.bank];
     let pattern = &bank.patterns[app.editor_ctx.pattern];
 
-    // Layout: [Transport] [Live] [Tempo] [Bank] [Pattern] [Stats]
-    let [transport_area, live_area, tempo_area, bank_area, pattern_area, stats_area] =
-        Layout::horizontal([
-            Constraint::Min(12),
-            Constraint::Length(9),
-            Constraint::Min(14),
-            Constraint::Fill(1),
-            Constraint::Fill(2),
-            Constraint::Min(20),
-        ])
-        .areas(area);
+    let (transport_area, live_area, tempo_area, bank_area, pattern_area, stats_area) =
+        if area.height == 1 {
+            let [t, l, tp, b, p, s] = Layout::horizontal([
+                Constraint::Min(12),
+                Constraint::Length(9),
+                Constraint::Min(14),
+                Constraint::Fill(1),
+                Constraint::Fill(2),
+                Constraint::Min(20),
+            ])
+            .areas(area);
+            (t, l, tp, b, p, s)
+        } else {
+            let [line1, line2] = Layout::vertical([
+                Constraint::Length(1),
+                Constraint::Length(1),
+            ])
+            .areas(area);
+
+            let [t, l, tp, s] = Layout::horizontal([
+                Constraint::Min(12),
+                Constraint::Length(9),
+                Constraint::Fill(1),
+                Constraint::Min(20),
+            ])
+            .areas(line1);
+
+            let [b, p] = Layout::horizontal([
+                Constraint::Fill(1),
+                Constraint::Fill(2),
+            ])
+            .areas(line2);
+
+            (t, l, tp, b, p, s)
+        };
 
     // Transport block
     let (transport_bg, transport_text) = if app.playback.playing {
@@ -619,28 +736,24 @@ fn render_modal(frame: &mut Frame, app: &App, snapshot: &SequencerSnapshot, term
             let show_search = app.editor_ctx.editor.search_active()
                 || !app.editor_ctx.editor.search_query().is_empty();
 
-            let (search_area, editor_area, hint_area) = if show_search {
-                let search_area = Rect::new(inner.x, inner.y, inner.width, 1);
-                let editor_area = Rect::new(
-                    inner.x,
-                    inner.y + 1,
-                    inner.width,
-                    inner.height.saturating_sub(2),
-                );
-                let hint_area =
-                    Rect::new(inner.x, inner.y + 1 + editor_area.height, inner.width, 1);
-                (Some(search_area), editor_area, hint_area)
+            let reserved_lines = 1 + if show_search { 1 } else { 0 };
+            let editor_height = inner.height.saturating_sub(reserved_lines);
+
+            let mut y = inner.y;
+
+            let search_area = if show_search {
+                let area = Rect::new(inner.x, y, inner.width, 1);
+                y += 1;
+                Some(area)
             } else {
-                let editor_area = Rect::new(
-                    inner.x,
-                    inner.y,
-                    inner.width,
-                    inner.height.saturating_sub(1),
-                );
-                let hint_area = Rect::new(inner.x, inner.y + editor_area.height, inner.width, 1);
-                (None, editor_area, hint_area)
+                None
             };
 
+            let editor_area = Rect::new(inner.x, y, inner.width, editor_height);
+            y += editor_height;
+
+            let hint_area = Rect::new(inner.x, y, inner.width, 1);
+
             if let Some(sa) = search_area {
                 let style = if app.editor_ctx.editor.search_active() {
                     Style::default().fg(Color::Yellow)
@@ -671,32 +784,52 @@ fn render_modal(frame: &mut Frame, app: &App, snapshot: &SequencerSnapshot, term
 
             let dim = Style::default().fg(Color::DarkGray);
             let key = Style::default().fg(Color::Yellow);
-            let hint = if app.editor_ctx.editor.search_active() {
-                Line::from(vec![
+
+            if app.editor_ctx.editor.search_active() {
+                let hint = Line::from(vec![
                     Span::styled("Enter", key),
                     Span::styled(" confirm  ", dim),
                     Span::styled("Esc", key),
                     Span::styled(" cancel", dim),
+                ]);
+                frame.render_widget(Paragraph::new(hint).alignment(Alignment::Right), hint_area);
+            } else if app.editor_ctx.show_stack {
+                let stack_text = compute_stack_display(text_lines, &app.editor_ctx.editor, &app.editor_ctx.stack_cache);
+                let hint = Line::from(vec![
+                    Span::styled("Esc", key),
+                    Span::styled(" save  ", dim),
+                    Span::styled("C-e", key),
+                    Span::styled(" eval  ", dim),
+                    Span::styled("C-s", key),
+                    Span::styled(" hide", dim),
+                ]);
+                let [hint_left, stack_right] = Layout::horizontal([
+                    Constraint::Length(hint.width() as u16),
+                    Constraint::Fill(1),
                 ])
+                .areas(hint_area);
+                frame.render_widget(Paragraph::new(hint), hint_left);
+                frame.render_widget(
+                    Paragraph::new(Span::styled(stack_text, dim)).alignment(Alignment::Right),
+                    stack_right,
+                );
             } else {
-                Line::from(vec![
+                let hint = Line::from(vec![
                     Span::styled("Esc", key),
                     Span::styled(" save  ", dim),
                     Span::styled("C-e", key),
                     Span::styled(" eval  ", dim),
                     Span::styled("C-f", key),
                     Span::styled(" find  ", dim),
-                    Span::styled("C-n", key),
-                    Span::styled("/", dim),
-                    Span::styled("C-p", key),
-                    Span::styled(" next/prev  ", dim),
+                    Span::styled("C-s", key),
+                    Span::styled(" stack  ", dim),
                     Span::styled("C-u", key),
                     Span::styled("/", dim),
                     Span::styled("C-r", key),
                     Span::styled(" undo/redo", dim),
-                ])
-            };
-            frame.render_widget(Paragraph::new(hint).alignment(Alignment::Right), hint_area);
+                ]);
+                frame.render_widget(Paragraph::new(hint).alignment(Alignment::Right), hint_area);
+            }
         }
         Modal::PatternProps {
             bank,

tests/forth.rs

@@ -48,3 +48,6 @@ mod list_words;
 
 #[path = "forth/ramps.rs"]
 mod ramps;
+
+#[path = "forth/generator.rs"]
+mod generator;

tests/forth/definitions.rs

@@ -46,8 +46,8 @@ fn word_defined_in_one_forth_available_in_same() {
 }
 
 #[test]
-fn unknown_word_errors() {
-    expect_error("nosuchword", "unknown word");
+fn unknown_word_becomes_string() {
+    expect_str("nosuchword", "nosuchword");
 }
 
 #[test]

tests/forth/errors.rs

@@ -11,8 +11,8 @@ fn whitespace_only() {
 }
 
 #[test]
-fn unknown_word() {
-    expect_error("foobar", "unknown word");
+fn unknown_word_becomes_string() {
+    expect_str("foobar", "foobar");
 }
 
 #[test]
@@ -22,12 +22,12 @@ fn string_not_number() {
 
 #[test]
 fn comment_ignored() {
-    expect_int("1 (this is a comment) 2 +", 3);
+    expect_int("1 ;; this is a comment\n2 +", 3);
 }
 
 #[test]
 fn multiline_comment() {
-    expect_int("1 (multi\nline\ncomment) 2 +", 3);
+    expect_int("1 ;; first comment\n;; entire line comment\n2 +", 3);
 }
 
 #[test]
@@ -51,22 +51,6 @@ fn string_with_spaces() {
     }
 }
 
-#[test]
-fn list_count() {
-    let f = run("[ 1 2 3 ]");
-    assert_eq!(stack_int(&f), 3);
-}
-
-#[test]
-fn list_empty() {
-    expect_int("[ ]", 0);
-}
-
-#[test]
-fn list_preserves_values() {
-    expect_int("[ 10 20 ] drop +", 30);
-}
-
 #[test]
 fn conditional_based_on_step() {
     let ctx0 = ctx_with(|c| c.step = 0);

tests/forth/generator.rs

@@ -0,0 +1,104 @@
+use super::harness::*;
+use cagire::forth::Value;
+
+fn int(n: i64) -> Value {
+    Value::Int(n, None)
+}
+
+#[test]
+fn range_ascending() {
+    expect_stack("1 4 ..", &[int(1), int(2), int(3), int(4)]);
+}
+
+#[test]
+fn range_descending() {
+    expect_stack("4 1 ..", &[int(4), int(3), int(2), int(1)]);
+}
+
+#[test]
+fn range_single() {
+    expect_stack("3 3 ..", &[int(3)]);
+}
+
+#[test]
+fn range_negative() {
+    expect_stack("-2 1 ..", &[int(-2), int(-1), int(0), int(1)]);
+}
+
+#[test]
+fn range_underflow() {
+    expect_error("1 ..", "stack underflow");
+    expect_error("..", "stack underflow");
+}
+
+#[test]
+fn gen_basic() {
+    expect_stack("{ 42 } 3 gen", &[int(42), int(42), int(42)]);
+}
+
+#[test]
+fn gen_with_computation() {
+    // Each iteration: dup current value, add 1, result is new value
+    // 0 → dup(0,0) 1+(0,1) → pop 1, stack [0]
+    // 0 → dup(0,0) 1+(0,1) → pop 1, stack [0]
+    // So we get [0, 1, 1, 1] - the 0 stays, we collect three 1s
+    expect_stack("0 { dup 1 + } 3 gen", &[int(0), int(1), int(1), int(1)]);
+}
+
+#[test]
+fn gen_chained() {
+    // Start with 1, each iteration: dup, multiply by 2
+    // 1 → dup(1,1) 2*(1,2) → pop 2, stack [1]
+    // 1 → dup(1,1) 2*(1,2) → pop 2, stack [1]
+    expect_stack("1 { dup 2 * } 3 gen", &[int(1), int(2), int(2), int(2)]);
+}
+
+#[test]
+fn gen_zero() {
+    expect_stack("{ 1 } 0 gen", &[]);
+}
+
+#[test]
+fn gen_underflow() {
+    expect_error("3 gen", "stack underflow");
+}
+
+#[test]
+fn gen_not_a_number() {
+    expect_error("{ 1 } gen", "expected number");
+}
+
+#[test]
+fn gen_negative() {
+    expect_error("{ 1 } -1 gen", "gen count must be >= 0");
+}
+
+#[test]
+fn gen_empty_quot_error() {
+    expect_error("{ } 3 gen", "quotation must produce");
+}
+
+#[test]
+fn geom_growing() {
+    expect_stack("1 2 4 geom..", &[int(1), int(2), int(4), int(8)]);
+}
+
+#[test]
+fn geom_shrinking() {
+    expect_stack("8 0.5 4 geom..", &[int(8), int(4), int(2), int(1)]);
+}
+
+#[test]
+fn geom_single() {
+    expect_stack("5 2 1 geom..", &[int(5)]);
+}
+
+#[test]
+fn geom_zero_count() {
+    expect_stack("1 2 0 geom..", &[]);
+}
+
+#[test]
+fn geom_underflow() {
+    expect_error("1 2 geom..", "stack underflow");
+}

tests/forth/harness.rs

@@ -88,6 +88,10 @@ pub fn expect_int(script: &str, expected: i64) {
     expect_stack(script, &[Value::Int(expected, None)]);
 }
 
+pub fn expect_str(script: &str, expected: &str) {
+    expect_stack(script, &[Value::Str(expected.to_string(), None)]);
+}
+
 pub fn expect_float(script: &str, expected: f64) {
     let f = run(script);
     let stack = f.stack();

tests/forth/list_words.rs

@@ -1,124 +1,106 @@
 use super::harness::*;
 
 #[test]
-fn choose_word_from_list() {
-    // 1 2 [ + - ] choose: picks + or -, applies to 1 2
-    // With seed 42, choose picks one deterministically
+fn choose_from_stack() {
     let f = forth();
     let ctx = default_ctx();
-    f.evaluate("1 2 [ + - ] choose", &ctx).unwrap();
+    f.evaluate("1 2 3 3 choose", &ctx).unwrap();
     let val = stack_int(&f);
-    assert!(val == 3 || val == -1, "expected 3 or -1, got {}", val);
+    assert!(val >= 1 && val <= 3, "expected 1, 2, or 3, got {}", val);
 }
 
 #[test]
-fn cycle_word_from_list() {
-    // At runs=0, picks first word (dup)
+fn cycle_by_runs() {
     let ctx = ctx_with(|c| c.runs = 0);
-    let f = run_ctx("5 < dup nip >", &ctx);
-    assert_eq!(stack_int(&f), 5); // dup leaves 5 5, but stack check takes top
-
-    // At runs=1, picks second word (2 *)
-    let f = forth();
-    let ctx = ctx_with(|c| c.runs = 1);
-    f.evaluate(": double 2 * ; 5 < dup double >", &ctx).unwrap();
+    let f = run_ctx("10 20 30 3 cycle", &ctx);
     assert_eq!(stack_int(&f), 10);
-}
 
-#[test]
-fn user_word_in_list() {
-    let f = forth();
-    let ctx = ctx_with(|c| c.runs = 0);
-    f.evaluate(": add3 3 + ; : add5 5 + ; 10 < add3 add5 >", &ctx).unwrap();
-    assert_eq!(stack_int(&f), 13); // runs=0 picks add3
-}
-
-#[test]
-fn user_word_in_list_second() {
-    let f = forth();
     let ctx = ctx_with(|c| c.runs = 1);
-    f.evaluate(": add3 3 + ; : add5 5 + ; 10 < add3 add5 >", &ctx).unwrap();
-    assert_eq!(stack_int(&f), 15); // runs=1 picks add5
-}
+    let f = run_ctx("10 20 30 3 cycle", &ctx);
+    assert_eq!(stack_int(&f), 20);
 
-#[test]
-fn values_in_list_still_work() {
-    // Numbers inside lists should still push as values (not quotations)
-    let ctx = ctx_with(|c| c.runs = 0);
-    let f = run_ctx("< 10 20 30 >", &ctx);
-    assert_eq!(stack_int(&f), 10);
-}
-
-#[test]
-fn values_in_list_cycle() {
     let ctx = ctx_with(|c| c.runs = 2);
-    let f = run_ctx("< 10 20 30 >", &ctx);
+    let f = run_ctx("10 20 30 3 cycle", &ctx);
+    assert_eq!(stack_int(&f), 30);
+
+    let ctx = ctx_with(|c| c.runs = 3);
+    let f = run_ctx("10 20 30 3 cycle", &ctx);
+    assert_eq!(stack_int(&f), 10);
+}
+
+#[test]
+fn pcycle_by_iter() {
+    let ctx = ctx_with(|c| c.iter = 0);
+    let f = run_ctx("10 20 30 3 pcycle", &ctx);
+    assert_eq!(stack_int(&f), 10);
+
+    let ctx = ctx_with(|c| c.iter = 1);
+    let f = run_ctx("10 20 30 3 pcycle", &ctx);
+    assert_eq!(stack_int(&f), 20);
+
+    let ctx = ctx_with(|c| c.iter = 2);
+    let f = run_ctx("10 20 30 3 pcycle", &ctx);
     assert_eq!(stack_int(&f), 30);
 }
 
 #[test]
-fn mixed_values_and_words() {
-    // Values stay as values, words become quotations
-    // [ 10 20 ] choose just picks a number
-    let f = forth();
-    let ctx = default_ctx();
-    f.evaluate("[ 10 20 ] choose", &ctx).unwrap();
-    let val = stack_int(&f);
-    assert!(val == 10 || val == 20, "expected 10 or 20, got {}", val);
-}
-
-#[test]
-fn word_with_sound_params() {
-    let f = forth();
+fn cycle_with_quotations() {
     let ctx = ctx_with(|c| c.runs = 0);
-    let outputs = f.evaluate(
-        ": myverb 0.5 verb ; \"sine\" s 440 freq < myverb > .",
-        &ctx
-    ).unwrap();
-    assert_eq!(outputs.len(), 1);
-    assert!(outputs[0].contains("verb/0.5"), "expected verb/0.5 in {}", outputs[0]);
-}
-
-#[test]
-fn arithmetic_word_in_list() {
-    // 3 4 [ + ] choose -> picks + (only option), applies to 3 4 = 7
-    let ctx = ctx_with(|c| c.runs = 0);
-    let f = run_ctx("3 4 < + >", &ctx);
-    assert_eq!(stack_int(&f), 7);
-}
-
-#[test]
-fn pcycle_word_from_list() {
-    let ctx = ctx_with(|c| c.iter = 0);
-    let f = run_ctx("10 << dup 2 * >>", &ctx);
-    // iter=0 picks dup: 10 10
+    let f = run_ctx("5 { dup } { 2 * } 2 cycle", &ctx);
     let stack = f.stack();
     assert_eq!(stack.len(), 2);
+    assert_eq!(stack_int(&f), 5);
+
+    let ctx = ctx_with(|c| c.runs = 1);
+    let f = run_ctx("5 { dup } { 2 * } 2 cycle", &ctx);
     assert_eq!(stack_int(&f), 10);
 }
 
 #[test]
-fn pcycle_word_second() {
-    let ctx = ctx_with(|c| c.iter = 1);
-    let f = run_ctx("10 << dup 2 * >>", &ctx);
-    // iter=1 picks "2 *" — but wait, each token is its own element
-    // so << dup 2 * >> has 3 elements: {dup}, 2, {*}
-    // iter=1 picks element index 1 which is value 2
-    assert_eq!(stack_int(&f), 2);
-}
-
-#[test]
-fn multi_op_quotation_in_list() {
-    // Use { } for multi-op quotations inside lists
+fn cycle_executes_quotation() {
     let ctx = ctx_with(|c| c.runs = 0);
-    let f = run_ctx("10 < { 2 * } { 3 + } >", &ctx);
-    assert_eq!(stack_int(&f), 20); // runs=0 picks {2 *}
+    let f = run_ctx("10 { 3 + } { 5 + } 2 cycle", &ctx);
+    assert_eq!(stack_int(&f), 13);
 }
 
 #[test]
-fn multi_op_quotation_second() {
-    let ctx = ctx_with(|c| c.runs = 1);
-    let f = run_ctx("10 < { 2 * } { 3 + } >", &ctx);
-    assert_eq!(stack_int(&f), 13); // runs=1 picks {3 +}
+fn dupn_basic() {
+    // 5 3 dupn -> 5 5 5, then + + -> 15
+    expect_int("5 3 dupn + +", 15);
 }
 
+#[test]
+fn dupn_alias() {
+    expect_int("5 3 ! + +", 15);
+}
+
+#[test]
+fn tcycle_creates_cycle_list() {
+    let outputs = expect_outputs(r#"0.0 at 60 64 67 3 tcycle note sine s ."#, 1);
+    assert!(outputs[0].contains("note/60"));
+}
+
+#[test]
+fn tcycle_with_multiple_emits() {
+    let f = forth();
+    let ctx = default_ctx();
+    let outputs = f.evaluate(r#"0 0.5 2 at 60 64 2 tcycle note sine s ."#, &ctx).unwrap();
+    assert_eq!(outputs.len(), 2);
+    assert!(outputs[0].contains("note/60"));
+    assert!(outputs[1].contains("note/64"));
+}
+
+#[test]
+fn cycle_zero_count_error() {
+    expect_error("1 2 3 0 cycle", "cycle count must be > 0");
+}
+
+#[test]
+fn choose_zero_count_error() {
+    expect_error("1 2 3 0 choose", "choose count must be > 0");
+}
+
+#[test]
+fn tcycle_zero_count_error() {
+    expect_error("1 2 3 0 tcycle", "tcycle count must be > 0");
+}

tests/forth/temporal.rs

@@ -42,15 +42,19 @@ fn get_sounds(outputs: &[String]) -> Vec<String> {
         .collect()
 }
 
+fn get_param(outputs: &[String], param: &str) -> Vec<f64> {
+    outputs
+        .iter()
+        .map(|o| parse_params(o).get(param).copied().unwrap_or(0.0))
+        .collect()
+}
+
 const EPSILON: f64 = 1e-9;
 
 fn approx_eq(a: f64, b: f64) -> bool {
     (a - b).abs() < EPSILON
 }
 
-// At 120 BPM, speed 1.0: stepdur = 60/120/4/1 = 0.125s
-// Root duration = 4 * stepdur = 0.5s
-
 #[test]
 fn stepdur_baseline() {
     let f = run("stepdur");
@@ -65,72 +69,14 @@ fn single_emit() {
 }
 
 #[test]
-fn implicit_subdivision_2() {
-    let outputs = expect_outputs(r#""kick" s . ."#, 2);
-    let deltas = get_deltas(&outputs);
-    let step = 0.5 / 2.0;
-    assert!(approx_eq(deltas[0], 0.0), "first slot at 0");
-    assert!(approx_eq(deltas[1], step), "second slot at {}, got {}", step, deltas[1]);
-}
-
-#[test]
-fn implicit_subdivision_4() {
+fn multiple_emits_all_at_zero() {
     let outputs = expect_outputs(r#""kick" s . . . ."#, 4);
     let deltas = get_deltas(&outputs);
-    let step = 0.5 / 4.0;
     for (i, delta) in deltas.iter().enumerate() {
-        let expected = step * i as f64;
-        assert!(
-            approx_eq(*delta, expected),
-            "slot {}: expected {}, got {}",
-            i, expected, delta
-        );
+        assert!(approx_eq(*delta, 0.0), "emit {}: expected delta 0, got {}", i, delta);
     }
 }
 
-#[test]
-fn implicit_subdivision_3() {
-    let outputs = expect_outputs(r#""kick" s . . ."#, 3);
-    let deltas = get_deltas(&outputs);
-    let step = 0.5 / 3.0;
-    assert!(approx_eq(deltas[0], 0.0));
-    assert!(approx_eq(deltas[1], step), "got {}", deltas[1]);
-    assert!(approx_eq(deltas[2], 2.0 * step), "got {}", deltas[2]);
-}
-
-#[test]
-fn silence_creates_gap() {
-    let outputs = expect_outputs(r#""kick" s . _ ."#, 2);
-    let deltas = get_deltas(&outputs);
-    let step = 0.5 / 3.0;
-    assert!(approx_eq(deltas[0], 0.0), "first at 0");
-    assert!(
-        approx_eq(deltas[1], 2.0 * step),
-        "third slot (after silence) at {}, got {}",
-        2.0 * step,
-        deltas[1]
-    );
-}
-
-#[test]
-fn silence_at_start() {
-    let outputs = expect_outputs(r#""kick" s _ ."#, 1);
-    let deltas = get_deltas(&outputs);
-    let step = 0.5 / 2.0;
-    assert!(
-        approx_eq(deltas[0], step),
-        "emit after silence at {}, got {}",
-        step,
-        deltas[0]
-    );
-}
-
-#[test]
-fn silence_only() {
-    let outputs = expect_outputs(r#""kick" s _"#, 0);
-    assert!(outputs.is_empty(), "silence only should produce no output");
-}
-
 #[test]
 fn sound_persists() {
     let outputs = expect_outputs(r#""kick" s . . "hat" s . ."#, 4);
@@ -149,67 +95,36 @@ fn alternating_sounds() {
 }
 
 #[test]
-fn dur_matches_slot_duration() {
-    let outputs = expect_outputs(r#""kick" s . . . ."#, 4);
+fn dur_is_step_duration() {
+    let outputs = expect_outputs(r#""kick" s ."#, 1);
     let durs = get_durs(&outputs);
-    let expected_dur = 0.5 / 4.0;
-    for (i, dur) in durs.iter().enumerate() {
-        assert!(
-            approx_eq(*dur, expected_dur),
-            "slot {} dur: expected {}, got {}",
-            i, expected_dur, dur
-        );
-    }
+    assert!(approx_eq(durs[0], 0.125), "dur should be step_duration (0.125), got {}", durs[0]);
 }
 
 #[test]
-fn tempo_affects_subdivision() {
-    let ctx = ctx_with(|c| c.tempo = 60.0);
-    let f = forth();
-    let outputs = f.evaluate(r#""kick" s . ."#, &ctx).unwrap();
-    let deltas = get_deltas(&outputs);
-    // At 60 BPM: stepdur = 0.25, root dur = 1.0
-    let step = 1.0 / 2.0;
-    assert!(approx_eq(deltas[0], 0.0));
-    assert!(approx_eq(deltas[1], step), "got {}", deltas[1]);
-}
-
-#[test]
-fn speed_affects_subdivision() {
-    let ctx = ctx_with(|c| c.speed = 2.0);
-    let f = forth();
-    let outputs = f.evaluate(r#""kick" s . ."#, &ctx).unwrap();
-    let deltas = get_deltas(&outputs);
-    // At speed 2.0: stepdur = 0.0625, root dur = 0.25
-    let step = 0.25 / 2.0;
-    assert!(approx_eq(deltas[0], 0.0));
-    assert!(approx_eq(deltas[1], step), "got {}", deltas[1]);
-}
-
-#[test]
-fn cycle_picks_by_step() {
+fn cycle_picks_by_runs() {
     for runs in 0..4 {
         let ctx = ctx_with(|c| c.runs = runs);
         let f = forth();
-        let outputs = f.evaluate(r#""kick" s < . _ >"#, &ctx).unwrap();
+        let outputs = f.evaluate(r#""kick" s { . } { } 2 cycle"#, &ctx).unwrap();
         if runs % 2 == 0 {
-            assert_eq!(outputs.len(), 1, "runs={}: . should be picked", runs);
+            assert_eq!(outputs.len(), 1, "runs={}: emit should be picked", runs);
         } else {
-            assert_eq!(outputs.len(), 0, "runs={}: _ should be picked", runs);
+            assert_eq!(outputs.len(), 0, "runs={}: no-op should be picked", runs);
         }
     }
 }
 
 #[test]
-fn pcycle_picks_by_pattern() {
+fn pcycle_picks_by_iter() {
     for iter in 0..4 {
         let ctx = ctx_with(|c| c.iter = iter);
         let f = forth();
-        let outputs = f.evaluate(r#""kick" s << . _ >>"#, &ctx).unwrap();
+        let outputs = f.evaluate(r#""kick" s { . } { } 2 pcycle"#, &ctx).unwrap();
         if iter % 2 == 0 {
-            assert_eq!(outputs.len(), 1, "iter={}: . should be picked", iter);
+            assert_eq!(outputs.len(), 1, "iter={}: emit should be picked", iter);
         } else {
-            assert_eq!(outputs.len(), 0, "iter={}: _ should be picked", iter);
+            assert_eq!(outputs.len(), 0, "iter={}: no-op should be picked", iter);
         }
     }
 }
@@ -219,7 +134,10 @@ fn cycle_with_sounds() {
     for runs in 0..3 {
         let ctx = ctx_with(|c| c.runs = runs);
         let f = forth();
-        let outputs = f.evaluate(r#"< { "kick" s . } { "hat" s . } { "snare" s . } >"#, &ctx).unwrap();
+        let outputs = f.evaluate(
+            r#"{ "kick" s . } { "hat" s . } { "snare" s . } 3 cycle"#,
+            &ctx
+        ).unwrap();
         assert_eq!(outputs.len(), 1, "runs={}: expected 1 output", runs);
         let sounds = get_sounds(&outputs);
         let expected = ["kick", "hat", "snare"][runs % 3];
@@ -227,143 +145,6 @@ fn cycle_with_sounds() {
     }
 }
 
-#[test]
-fn dot_alias_for_emit() {
-    let outputs = expect_outputs(r#""kick" s . . . ."#, 4);
-    let sounds = get_sounds(&outputs);
-    assert_eq!(sounds, vec!["kick", "kick", "kick", "kick"]);
-}
-
-#[test]
-fn dot_with_silence() {
-    let outputs = expect_outputs(r#""kick" s . _ . _"#, 2);
-    let deltas = get_deltas(&outputs);
-    let step = 0.5 / 4.0;
-    assert!(approx_eq(deltas[0], 0.0));
-    assert!(approx_eq(deltas[1], 2.0 * step));
-}
-
-#[test]
-fn div_basic_subdivision() {
-    let outputs = expect_outputs(r#"div "kick" s . "hat" s . ~"#, 2);
-    let deltas = get_deltas(&outputs);
-    let sounds = get_sounds(&outputs);
-    assert_eq!(sounds, vec!["kick", "hat"]);
-    assert!(approx_eq(deltas[0], 0.0));
-    assert!(approx_eq(deltas[1], 0.25), "second should be at 0.25, got {}", deltas[1]);
-}
-
-#[test]
-fn div_sequential() {
-    // Two consecutive divs each claim a slot in root, so they're sequential
-    let outputs = expect_outputs(r#"div "kick" s . ~ div "hat" s . ~"#, 2);
-    let deltas = get_deltas(&outputs);
-    let sounds = get_sounds(&outputs);
-    assert_eq!(sounds, vec!["kick", "hat"]);
-    assert!(approx_eq(deltas[0], 0.0));
-    assert!(approx_eq(deltas[1], 0.25), "second div at slot 1, got {}", deltas[1]);
-}
-
-#[test]
-fn div_with_root_emit() {
-    // kick claims slot 0 at root, div claims slot 1 at root
-    let outputs = expect_outputs(r#""kick" s . div "hat" s . ~"#, 2);
-    let deltas = get_deltas(&outputs);
-    let sounds = get_sounds(&outputs);
-    assert_eq!(sounds, vec!["kick", "hat"]);
-    assert!(approx_eq(deltas[0], 0.0), "kick at slot 0");
-    assert!(approx_eq(deltas[1], 0.25), "hat at slot 1, got {}", deltas[1]);
-}
-
-#[test]
-fn div_nested() {
-    // kick claims slot 0 in outer div, inner div claims slot 1
-    // Inner div's 2 hats subdivide its slot (0.25 duration) into 2 sub-slots
-    let outputs = expect_outputs(r#"div "kick" s . div "hat" s . . ~ ~"#, 3);
-    let sounds = get_sounds(&outputs);
-    let deltas = get_deltas(&outputs);
-    // Output order: kick (slot 0), then hats (slot 1 subdivided)
-    assert_eq!(sounds[0], "kick");
-    assert_eq!(sounds[1], "hat");
-    assert_eq!(sounds[2], "hat");
-    // Outer div has 2 slots of 0.25 each
-    // kick at slot 0 -> delta 0
-    // inner div at slot 1 -> starts at 0.25, subdivided into 2 -> hats at 0.25 and 0.375
-    assert!(approx_eq(deltas[0], 0.0), "kick at 0, got {}", deltas[0]);
-    assert!(approx_eq(deltas[1], 0.25), "first hat at 0.25, got {}", deltas[1]);
-    assert!(approx_eq(deltas[2], 0.375), "second hat at 0.375, got {}", deltas[2]);
-}
-
-#[test]
-fn div_with_silence() {
-    let outputs = expect_outputs(r#"div "kick" s . _ ~"#, 1);
-    let deltas = get_deltas(&outputs);
-    assert!(approx_eq(deltas[0], 0.0));
-}
-
-#[test]
-fn unmatched_scope_terminator_error() {
-    let f = forth();
-    let result = f.evaluate(r#""kick" s . ~"#, &default_ctx());
-    assert!(result.is_err(), "unmatched ~ should error");
-}
-
-#[test]
-fn stack_superposes_sounds() {
-    let outputs = expect_outputs(r#"stack "kick" s . "hat" s . ~"#, 2);
-    let deltas = get_deltas(&outputs);
-    let sounds = get_sounds(&outputs);
-    assert_eq!(sounds.len(), 2);
-    // Both at delta 0 (stacked/superposed)
-    assert!(approx_eq(deltas[0], 0.0));
-    assert!(approx_eq(deltas[1], 0.0));
-}
-
-#[test]
-fn stack_with_multiple_emits() {
-    let outputs = expect_outputs(r#"stack "kick" s . . . . ~"#, 4);
-    let deltas = get_deltas(&outputs);
-    // All 4 kicks at delta 0
-    for (i, delta) in deltas.iter().enumerate() {
-        assert!(approx_eq(*delta, 0.0), "emit {} should be at 0, got {}", i, delta);
-    }
-}
-
-#[test]
-fn stack_inside_div() {
-    // div subdivides, stack inside superposes
-    // stack doesn't claim a slot in parent div, so snare is also at 0
-    let outputs = expect_outputs(r#"div stack "kick" s . "hat" s . ~ "snare" s . ~"#, 3);
-    let deltas = get_deltas(&outputs);
-    let sounds = get_sounds(&outputs);
-    // stack resolves first (kick, hat at 0), then div resolves (snare at 0)
-    // since stack doesn't consume a slot in the parent div
-    assert_eq!(sounds[0], "kick");
-    assert_eq!(sounds[1], "hat");
-    assert_eq!(sounds[2], "snare");
-    assert!(approx_eq(deltas[0], 0.0));
-    assert!(approx_eq(deltas[1], 0.0));
-    assert!(approx_eq(deltas[2], 0.0), "snare at 0, got {}", deltas[2]);
-}
-
-#[test]
-fn div_nested_with_sibling() {
-    // Inner div claims slot 0, snare claims slot 1
-    // Inner div's kick/hat subdivide slot 0
-    let outputs = expect_outputs(r#"div div "kick" s . "hat" s . ~ "snare" s . ~"#, 3);
-    let deltas = get_deltas(&outputs);
-    let sounds = get_sounds(&outputs);
-    // Outer div has 2 slots of 0.25 each
-    // Inner div at slot 0: kick at 0, hat at 0.125
-    // snare at slot 1: delta 0.25
-    assert_eq!(sounds[0], "kick");
-    assert_eq!(sounds[1], "hat");
-    assert_eq!(sounds[2], "snare");
-    assert!(approx_eq(deltas[0], 0.0), "kick at 0, got {}", deltas[0]);
-    assert!(approx_eq(deltas[1], 0.125), "hat at 0.125, got {}", deltas[1]);
-    assert!(approx_eq(deltas[2], 0.25), "snare at 0.25, got {}", deltas[2]);
-}
-
 #[test]
 fn emit_n_basic() {
     let outputs = expect_outputs(r#""kick" s 4 .!"#, 4);
@@ -384,3 +165,106 @@ fn emit_n_negative_error() {
     assert!(result.is_err());
 }
 
+#[test]
+fn at_single_delta() {
+    let outputs = expect_outputs(r#"0.5 at "kick" s ."#, 1);
+    let deltas = get_deltas(&outputs);
+    let step_dur = 0.125;
+    assert!(approx_eq(deltas[0], 0.5 * step_dur), "expected delta at 0.5 of step, got {}", deltas[0]);
+}
+
+#[test]
+fn at_list_deltas() {
+    let outputs = expect_outputs(r#"0 0.5 2 at "kick" s ."#, 2);
+    let deltas = get_deltas(&outputs);
+    let step_dur = 0.125;
+    assert!(approx_eq(deltas[0], 0.0), "expected delta 0, got {}", deltas[0]);
+    assert!(approx_eq(deltas[1], 0.5 * step_dur), "expected delta at 0.5 of step, got {}", deltas[1]);
+}
+
+#[test]
+fn at_three_deltas() {
+    let outputs = expect_outputs(r#"0 0.33 0.67 3 at "kick" s ."#, 3);
+    let deltas = get_deltas(&outputs);
+    let step_dur = 0.125;
+    assert!(approx_eq(deltas[0], 0.0), "expected delta 0");
+    assert!((deltas[1] - 0.33 * step_dur).abs() < 0.001, "expected delta at 0.33 of step");
+    assert!((deltas[2] - 0.67 * step_dur).abs() < 0.001, "expected delta at 0.67 of step");
+}
+
+#[test]
+fn at_persists_across_emits() {
+    let outputs = expect_outputs(r#"0 0.5 2 at "kick" s . "hat" s ."#, 4);
+    let sounds = get_sounds(&outputs);
+    assert_eq!(sounds, vec!["kick", "kick", "hat", "hat"]);
+}
+
+#[test]
+fn tcycle_basic() {
+    let outputs = expect_outputs(r#"0 0.5 0.75 3 at 60 64 67 3 tcycle note sine s ."#, 3);
+    let notes = get_param(&outputs, "note");
+    assert_eq!(notes, vec![60.0, 64.0, 67.0]);
+}
+
+#[test]
+fn tcycle_wraps() {
+    let outputs = expect_outputs(r#"0 0.33 0.67 3 at 60 64 2 tcycle note sine s ."#, 3);
+    let notes = get_param(&outputs, "note");
+    assert_eq!(notes, vec![60.0, 64.0, 60.0]);
+}
+
+#[test]
+fn tcycle_with_sound() {
+    let outputs = expect_outputs(r#"0 0.5 2 at kick hat 2 tcycle s ."#, 2);
+    let sounds = get_sounds(&outputs);
+    assert_eq!(sounds, vec!["kick", "hat"]);
+}
+
+#[test]
+fn tcycle_multiple_params() {
+    let outputs = expect_outputs(r#"0 0.5 0.75 3 at 60 64 67 3 tcycle note 0.5 1.0 2 tcycle gain sine s ."#, 3);
+    let notes = get_param(&outputs, "note");
+    let gains = get_param(&outputs, "gain");
+    assert_eq!(notes, vec![60.0, 64.0, 67.0]);
+    assert_eq!(gains, vec![0.5, 1.0, 0.5]);
+}
+
+#[test]
+fn at_reset_with_zero() {
+    let outputs = expect_outputs(r#"0 0.5 2 at "kick" s . 0.0 at "hat" s ."#, 3);
+    let sounds = get_sounds(&outputs);
+    assert_eq!(sounds, vec!["kick", "kick", "hat"]);
+}
+
+#[test]
+fn tcycle_records_selected_spans() {
+    use cagire::forth::ExecutionTrace;
+
+    let f = forth();
+    let mut trace = ExecutionTrace::default();
+    let script = r#"0 0.5 2 at kick hat 2 tcycle s ."#;
+    f.evaluate_with_trace(script, &default_ctx(), &mut trace).unwrap();
+
+    // Should have 4 selected spans:
+    // - 2 for at deltas (0 and 0.5)
+    // - 2 for tcycle sound values (kick and hat)
+    assert_eq!(trace.selected_spans.len(), 4, "expected 4 selected spans (2 at + 2 tcycle)");
+}
+
+#[test]
+fn at_records_selected_spans() {
+    use cagire::forth::ExecutionTrace;
+
+    let f = forth();
+    let mut trace = ExecutionTrace::default();
+    let script = r#"0 0.5 0.75 3 at "kick" s ."#;
+    f.evaluate_with_trace(script, &default_ctx(), &mut trace).unwrap();
+
+    // Should have 6 selected spans: 3 for at deltas + 3 for sound (one per emit)
+    assert_eq!(trace.selected_spans.len(), 6, "expected 6 selected spans (3 at + 3 sound)");
+
+    // Verify at delta spans (even indices: 0, 2, 4)
+    assert_eq!(&script[trace.selected_spans[0].start..trace.selected_spans[0].end], "0");
+    assert_eq!(&script[trace.selected_spans[2].start..trace.selected_spans[2].end], "0.5");
+    assert_eq!(&script[trace.selected_spans[4].start..trace.selected_spans[4].end], "0.75");
+}