diff --git a/crates/forth/src/ops.rs b/crates/forth/src/ops.rs
index 998f18c..ecbad3b 100644
--- a/crates/forth/src/ops.rs
+++ b/crates/forth/src/ops.rs
@@ -83,4 +83,7 @@ pub enum Op {
     ClearCmd,
     SetSpeed,
     At,
+    IntRange,
+    Generate,
+    GeomRange,
 }
diff --git a/crates/forth/src/types.rs b/crates/forth/src/types.rs
index b1768e8..1fb9db5 100644
--- a/crates/forth/src/types.rs
+++ b/crates/forth/src/types.rs
@@ -140,10 +140,8 @@ impl CmdRegister {
         &self.deltas
     }
 
-    pub(super) fn snapshot(&self) -> Option<(Value, Vec<(String, Value)>)> {
-        self.sound
-            .as_ref()
-            .map(|s| (s.clone(), self.params.clone()))
+    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) {
diff --git a/crates/forth/src/vm.rs b/crates/forth/src/vm.rs
index d8ea3af..9aa157b 100644
--- a/crates/forth/src/vm.rs
+++ b/crates/forth/src/vm.rs
@@ -1,5 +1,6 @@
 use rand::rngs::StdRng;
 use rand::{Rng as RngTrait, SeedableRng};
+use std::borrow::Cow;
 
 use super::compiler::compile_script;
 use super::ops::Op;
@@ -147,13 +148,11 @@ impl Forth {
 
         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 resolved_sound_val = resolve_cycling(&sound_val, emit_idx);
-            // Note: sound span is recorded by Op::Emit, not here
+            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);
-                    // Record selected span for params if they came from a CycleList
                     if let Value::CycleList(_) = v {
                         if let Some(span) = resolved.span() {
                             if let Some(trace) = trace_cell.borrow_mut().as_mut() {
@@ -164,7 +163,7 @@ impl Forth {
                     (k.clone(), resolved.to_param_string())
                 }).collect();
             emit_output(&sound, &resolved_params, ctx.step_duration(), delta_secs, outputs);
-            Ok(Some(resolved_sound_val))
+            Ok(Some(resolved_sound_val.into_owned()))
         };
 
         while pc < ops.len() {
@@ -630,8 +629,15 @@ impl Forth {
                     let top = stack.pop().ok_or("stack underflow")?;
                     let deltas = match &top {
                         Value::Float(..) => vec![top],
-                        Value::Int(n, _) if *n > 0 && stack.len() >= *n as usize => {
+                        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")?);
@@ -639,8 +645,7 @@ impl Forth {
                             vals.reverse();
                             vals
                         }
-                        Value::Int(..) => vec![top],
-                        _ => return Err("at expects number or list".into()),
+                        _ => return Err("at expects float or int count".into()),
                     };
                     cmd.set_deltas(deltas);
                 }
@@ -709,6 +714,50 @@ impl Forth {
                         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;
+                    }
+                }
             }
             pc += 1;
         }
@@ -717,31 +766,34 @@ impl Forth {
     }
 }
 
-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 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 emit_output(
     sound: &str,
@@ -765,7 +817,7 @@ fn emit_output(
         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();
             }
@@ -853,11 +905,11 @@ fn format_cmd(pairs: &[(String, String)]) -> String {
     format!("/{}", parts.join("/"))
 }
 
-fn resolve_cycling(val: &Value, emit_idx: usize) -> Value {
+fn resolve_cycling(val: &Value, emit_idx: usize) -> Cow<'_, Value> {
     match val {
         Value::CycleList(items) if !items.is_empty() => {
-            items[emit_idx % items.len()].clone()
+            Cow::Owned(items[emit_idx % items.len()].clone())
         }
-        other => other.clone(),
+        other => Cow::Borrowed(other),
     }
 }
diff --git a/crates/forth/src/words.rs b/crates/forth/src/words.rs
index 86c547e..a0b59b3 100644
--- a/crates/forth/src/words.rs
+++ b/crates/forth/src/words.rs
@@ -17,6 +17,7 @@ pub struct Word {
     pub desc: &'static str,
     pub example: &'static str,
     pub compile: WordCompile,
+    pub varargs: bool,
 }
 
 use WordCompile::*;
@@ -31,6 +32,7 @@ pub const WORDS: &[Word] = &[
         desc: "Duplicate top of stack",
         example: "3 dup => 3 3",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "dupn",
@@ -40,6 +42,7 @@ pub const WORDS: &[Word] = &[
         desc: "Duplicate a onto stack n times",
         example: "2 4 dupn => 2 2 2 2",
         compile: Simple,
+        varargs: true,
     },
     Word {
         name: "drop",
@@ -49,6 +52,7 @@ pub const WORDS: &[Word] = &[
         desc: "Remove top of stack",
         example: "1 2 drop => 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "swap",
@@ -58,6 +62,7 @@ pub const WORDS: &[Word] = &[
         desc: "Exchange top two items",
         example: "1 2 swap => 2 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "over",
@@ -67,6 +72,7 @@ pub const WORDS: &[Word] = &[
         desc: "Copy second to top",
         example: "1 2 over => 1 2 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "rot",
@@ -76,6 +82,7 @@ pub const WORDS: &[Word] = &[
         desc: "Rotate top three",
         example: "1 2 3 rot => 2 3 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "nip",
@@ -85,6 +92,7 @@ pub const WORDS: &[Word] = &[
         desc: "Remove second item",
         example: "1 2 nip => 2",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "tuck",
@@ -94,6 +102,7 @@ pub const WORDS: &[Word] = &[
         desc: "Copy top under second",
         example: "1 2 tuck => 2 1 2",
         compile: Simple,
+        varargs: false,
     },
     // Arithmetic
     Word {
@@ -104,6 +113,7 @@ pub const WORDS: &[Word] = &[
         desc: "Add",
         example: "2 3 + => 5",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "-",
@@ -113,6 +123,7 @@ pub const WORDS: &[Word] = &[
         desc: "Subtract",
         example: "5 3 - => 2",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "*",
@@ -122,6 +133,7 @@ pub const WORDS: &[Word] = &[
         desc: "Multiply",
         example: "3 4 * => 12",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "/",
@@ -131,6 +143,7 @@ pub const WORDS: &[Word] = &[
         desc: "Divide",
         example: "10 2 / => 5",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "mod",
@@ -140,6 +153,7 @@ pub const WORDS: &[Word] = &[
         desc: "Modulo",
         example: "7 3 mod => 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "neg",
@@ -149,6 +163,7 @@ pub const WORDS: &[Word] = &[
         desc: "Negate",
         example: "5 neg => -5",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "abs",
@@ -158,6 +173,7 @@ pub const WORDS: &[Word] = &[
         desc: "Absolute value",
         example: "-5 abs => 5",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "floor",
@@ -167,6 +183,7 @@ pub const WORDS: &[Word] = &[
         desc: "Round down to integer",
         example: "3.7 floor => 3",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "ceil",
@@ -176,6 +193,7 @@ pub const WORDS: &[Word] = &[
         desc: "Round up to integer",
         example: "3.2 ceil => 4",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "round",
@@ -185,6 +203,7 @@ pub const WORDS: &[Word] = &[
         desc: "Round to nearest integer",
         example: "3.5 round => 4",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "min",
@@ -194,6 +213,7 @@ pub const WORDS: &[Word] = &[
         desc: "Minimum of two values",
         example: "3 5 min => 3",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "max",
@@ -203,6 +223,7 @@ pub const WORDS: &[Word] = &[
         desc: "Maximum of two values",
         example: "3 5 max => 5",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "pow",
@@ -212,6 +233,7 @@ pub const WORDS: &[Word] = &[
         desc: "Exponentiation",
         example: "2 3 pow => 8",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "sqrt",
@@ -221,6 +243,7 @@ pub const WORDS: &[Word] = &[
         desc: "Square root",
         example: "16 sqrt => 4",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "sin",
@@ -230,6 +253,7 @@ pub const WORDS: &[Word] = &[
         desc: "Sine (radians)",
         example: "3.14159 2 / sin => 1.0",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "cos",
@@ -239,6 +263,7 @@ pub const WORDS: &[Word] = &[
         desc: "Cosine (radians)",
         example: "0 cos => 1.0",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "log",
@@ -248,6 +273,7 @@ pub const WORDS: &[Word] = &[
         desc: "Natural logarithm",
         example: "2.718 log => 1.0",
         compile: Simple,
+        varargs: false,
     },
     // Comparison
     Word {
@@ -258,6 +284,7 @@ pub const WORDS: &[Word] = &[
         desc: "Equal",
         example: "3 3 = => 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "!=",
@@ -267,6 +294,7 @@ pub const WORDS: &[Word] = &[
         desc: "Not equal",
         example: "3 4 != => 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "lt",
@@ -276,6 +304,7 @@ pub const WORDS: &[Word] = &[
         desc: "Less than",
         example: "2 3 lt => 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "gt",
@@ -285,6 +314,7 @@ pub const WORDS: &[Word] = &[
         desc: "Greater than",
         example: "3 2 gt => 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "<=",
@@ -294,6 +324,7 @@ pub const WORDS: &[Word] = &[
         desc: "Less or equal",
         example: "3 3 <= => 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: ">=",
@@ -303,6 +334,7 @@ pub const WORDS: &[Word] = &[
         desc: "Greater or equal",
         example: "3 3 >= => 1",
         compile: Simple,
+        varargs: false,
     },
     // Logic
     Word {
@@ -313,6 +345,7 @@ pub const WORDS: &[Word] = &[
         desc: "Logical and",
         example: "1 1 and => 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "or",
@@ -322,6 +355,7 @@ pub const WORDS: &[Word] = &[
         desc: "Logical or",
         example: "0 1 or => 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "not",
@@ -331,6 +365,7 @@ pub const WORDS: &[Word] = &[
         desc: "Logical not",
         example: "0 not => 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "xor",
@@ -340,6 +375,7 @@ pub const WORDS: &[Word] = &[
         desc: "Exclusive or",
         example: "1 0 xor => 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "nand",
@@ -349,6 +385,7 @@ pub const WORDS: &[Word] = &[
         desc: "Not and",
         example: "1 1 nand => 0",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "nor",
@@ -358,6 +395,7 @@ pub const WORDS: &[Word] = &[
         desc: "Not or",
         example: "0 0 nor => 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "ifelse",
@@ -367,6 +405,7 @@ pub const WORDS: &[Word] = &[
         desc: "Execute true-quot if true, else false-quot",
         example: "{ 1 } { 2 } coin ifelse",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "pick",
@@ -376,6 +415,7 @@ pub const WORDS: &[Word] = &[
         desc: "Execute nth quotation (0-indexed)",
         example: "{ 1 } { 2 } { 3 } 2 pick => 3",
         compile: Simple,
+        varargs: true,
     },
     // Sound
     Word {
@@ -386,6 +426,7 @@ pub const WORDS: &[Word] = &[
         desc: "Begin sound command",
         example: "\"kick\" sound",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: ".",
@@ -395,6 +436,7 @@ pub const WORDS: &[Word] = &[
         desc: "Emit current sound",
         example: "\"kick\" s . . . .",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: ".!",
@@ -404,6 +446,7 @@ pub const WORDS: &[Word] = &[
         desc: "Emit current sound n times",
         example: "\"kick\" s 4 .!",
         compile: Simple,
+        varargs: true,
     },
     // Variables (prefix syntax: @name to fetch, !name to store)
     Word {
@@ -414,6 +457,7 @@ pub const WORDS: &[Word] = &[
         desc: "Fetch variable value",
         example: "@freq => 440",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "!<var>",
@@ -423,6 +467,7 @@ pub const WORDS: &[Word] = &[
         desc: "Store value in variable",
         example: "440 !freq",
         compile: Simple,
+        varargs: false,
     },
     // Randomness
     Word {
@@ -433,6 +478,7 @@ pub const WORDS: &[Word] = &[
         desc: "Random in range. Int if both args are int, float otherwise",
         example: "1 6 rand => 4 | 0.0 1.0 rand => 0.42",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "seed",
@@ -442,6 +488,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set random seed",
         example: "12345 seed",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "coin",
@@ -451,6 +498,7 @@ pub const WORDS: &[Word] = &[
         desc: "50/50 random boolean",
         example: "coin => 0 or 1",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "chance",
@@ -460,6 +508,7 @@ pub const WORDS: &[Word] = &[
         desc: "Execute quotation with probability (0.0-1.0)",
         example: "{ 2 distort } 0.75 chance",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "prob",
@@ -469,6 +518,7 @@ pub const WORDS: &[Word] = &[
         desc: "Execute quotation with probability (0-100)",
         example: "{ 2 distort } 75 prob",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "choose",
@@ -478,6 +528,7 @@ pub const WORDS: &[Word] = &[
         desc: "Random pick from n items",
         example: "1 2 3 3 choose",
         compile: Simple,
+        varargs: true,
     },
     Word {
         name: "cycle",
@@ -487,6 +538,7 @@ pub const WORDS: &[Word] = &[
         desc: "Cycle through n items by step runs",
         example: "60 64 67 3 cycle",
         compile: Simple,
+        varargs: true,
     },
     Word {
         name: "pcycle",
@@ -496,6 +548,7 @@ pub const WORDS: &[Word] = &[
         desc: "Cycle through n items by pattern iteration",
         example: "60 64 67 3 pcycle",
         compile: Simple,
+        varargs: true,
     },
     Word {
         name: "tcycle",
@@ -505,6 +558,7 @@ pub const WORDS: &[Word] = &[
         desc: "Create cycle list for emit-time resolution",
         example: "60 64 67 3 tcycle note",
         compile: Simple,
+        varargs: true,
     },
     Word {
         name: "every",
@@ -514,6 +568,7 @@ pub const WORDS: &[Word] = &[
         desc: "True every nth iteration",
         example: "4 every",
         compile: Simple,
+        varargs: false,
     },
     // Probability shortcuts
     Word {
@@ -524,6 +579,7 @@ pub const WORDS: &[Word] = &[
         desc: "Always execute quotation",
         example: "{ 2 distort } always",
         compile: Probability(1.0),
+        varargs: false,
     },
     Word {
         name: "never",
@@ -533,6 +589,7 @@ pub const WORDS: &[Word] = &[
         desc: "Never execute quotation",
         example: "{ 2 distort } never",
         compile: Probability(0.0),
+        varargs: false,
     },
     Word {
         name: "often",
@@ -542,6 +599,7 @@ pub const WORDS: &[Word] = &[
         desc: "Execute quotation 75% of the time",
         example: "{ 2 distort } often",
         compile: Probability(0.75),
+        varargs: false,
     },
     Word {
         name: "sometimes",
@@ -551,6 +609,7 @@ pub const WORDS: &[Word] = &[
         desc: "Execute quotation 50% of the time",
         example: "{ 2 distort } sometimes",
         compile: Probability(0.5),
+        varargs: false,
     },
     Word {
         name: "rarely",
@@ -560,6 +619,7 @@ pub const WORDS: &[Word] = &[
         desc: "Execute quotation 25% of the time",
         example: "{ 2 distort } rarely",
         compile: Probability(0.25),
+        varargs: false,
     },
     Word {
         name: "almostNever",
@@ -569,6 +629,7 @@ pub const WORDS: &[Word] = &[
         desc: "Execute quotation 10% of the time",
         example: "{ 2 distort } almostNever",
         compile: Probability(0.1),
+        varargs: false,
     },
     Word {
         name: "almostAlways",
@@ -578,6 +639,7 @@ pub const WORDS: &[Word] = &[
         desc: "Execute quotation 90% of the time",
         example: "{ 2 distort } almostAlways",
         compile: Probability(0.9),
+        varargs: false,
     },
     // Context
     Word {
@@ -588,6 +650,7 @@ pub const WORDS: &[Word] = &[
         desc: "Current step index",
         example: "step => 0",
         compile: Context("step"),
+        varargs: false,
     },
     Word {
         name: "beat",
@@ -597,6 +660,7 @@ pub const WORDS: &[Word] = &[
         desc: "Current beat position",
         example: "beat => 4.5",
         compile: Context("beat"),
+        varargs: false,
     },
     Word {
         name: "bank",
@@ -606,6 +670,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set sample bank suffix",
         example: "\"a\" bank",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "pattern",
@@ -615,6 +680,7 @@ pub const WORDS: &[Word] = &[
         desc: "Current pattern index",
         example: "pattern => 0",
         compile: Context("pattern"),
+        varargs: false,
     },
     Word {
         name: "pbank",
@@ -624,6 +690,7 @@ pub const WORDS: &[Word] = &[
         desc: "Current pattern's bank index",
         example: "pbank => 0",
         compile: Context("bank"),
+        varargs: false,
     },
     Word {
         name: "tempo",
@@ -633,6 +700,7 @@ pub const WORDS: &[Word] = &[
         desc: "Current BPM",
         example: "tempo => 120.0",
         compile: Context("tempo"),
+        varargs: false,
     },
     Word {
         name: "phase",
@@ -642,6 +710,7 @@ pub const WORDS: &[Word] = &[
         desc: "Phase in bar (0-1)",
         example: "phase => 0.25",
         compile: Context("phase"),
+        varargs: false,
     },
     Word {
         name: "slot",
@@ -651,6 +720,7 @@ pub const WORDS: &[Word] = &[
         desc: "Current slot number",
         example: "slot => 0",
         compile: Context("slot"),
+        varargs: false,
     },
     Word {
         name: "runs",
@@ -660,6 +730,7 @@ pub const WORDS: &[Word] = &[
         desc: "Times this step ran",
         example: "runs => 3",
         compile: Context("runs"),
+        varargs: false,
     },
     Word {
         name: "iter",
@@ -669,6 +740,7 @@ pub const WORDS: &[Word] = &[
         desc: "Pattern iteration count",
         example: "iter => 2",
         compile: Context("iter"),
+        varargs: false,
     },
     Word {
         name: "stepdur",
@@ -678,6 +750,7 @@ pub const WORDS: &[Word] = &[
         desc: "Step duration in seconds",
         example: "stepdur => 0.125",
         compile: Context("stepdur"),
+        varargs: false,
     },
     // Live keys
     Word {
@@ -688,6 +761,7 @@ pub const WORDS: &[Word] = &[
         desc: "True when fill is on (f key)",
         example: "\"snare\" s . fill ?",
         compile: Context("fill"),
+        varargs: false,
     },
     // Music
     Word {
@@ -698,6 +772,7 @@ pub const WORDS: &[Word] = &[
         desc: "MIDI note to frequency",
         example: "69 mtof => 440.0",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "ftom",
@@ -707,6 +782,7 @@ pub const WORDS: &[Word] = &[
         desc: "Frequency to MIDI note",
         example: "440 ftom => 69.0",
         compile: Simple,
+        varargs: false,
     },
     // LFO
     Word {
@@ -717,6 +793,7 @@ pub const WORDS: &[Word] = &[
         desc: "Ramp [0,1]: fract(freq*beat)^curve",
         example: "0.25 2.0 ramp",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "range",
@@ -726,6 +803,7 @@ pub const WORDS: &[Word] = &[
         desc: "Scale [0,1] to [min,max]",
         example: "0.5 200 800 range => 500",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "linramp",
@@ -735,6 +813,7 @@ pub const WORDS: &[Word] = &[
         desc: "Linear ramp (curve=1)",
         example: "1.0 linramp",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "expramp",
@@ -744,6 +823,7 @@ pub const WORDS: &[Word] = &[
         desc: "Exponential ramp (curve=3)",
         example: "0.25 expramp",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "logramp",
@@ -753,6 +833,7 @@ pub const WORDS: &[Word] = &[
         desc: "Logarithmic ramp (curve=0.3)",
         example: "2.0 logramp",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "tri",
@@ -762,6 +843,7 @@ pub const WORDS: &[Word] = &[
         desc: "Triangle wave [0,1]: 0→1→0",
         example: "0.5 tri",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "perlin",
@@ -771,6 +853,7 @@ pub const WORDS: &[Word] = &[
         desc: "Perlin noise [0,1] sampled at freq*beat",
         example: "0.25 perlin",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "loop",
@@ -780,6 +863,7 @@ pub const WORDS: &[Word] = &[
         desc: "Fit sample to n beats",
         example: "\"break\" s 4 loop @",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "tempo!",
@@ -789,6 +873,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set global tempo",
         example: "140 tempo!",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "speed!",
@@ -798,6 +883,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set pattern speed multiplier",
         example: "2.0 speed!",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "chain",
@@ -807,15 +893,17 @@ pub const WORDS: &[Word] = &[
         desc: "Chain to bank/pattern (1-indexed) when current pattern ends",
         example: "1 4 chain",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "at",
         aliases: &[],
         category: "Time",
-        stack: "(list|n --)",
+        stack: "(v1..vn n --)",
         desc: "Set delta context for emit timing",
-        example: "[ 0 0.5 ] at kick s . => emits at 0 and 0.5 of step",
+        example: "0 0.5 2 at kick s . => emits at 0 and 0.5 of step",
         compile: Simple,
+        varargs: true,
     },
     // Quotations
     Word {
@@ -826,6 +914,7 @@ pub const WORDS: &[Word] = &[
         desc: "Execute quotation if true",
         example: "{ 2 distort } 0.5 chance ?",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "!?",
@@ -835,6 +924,7 @@ pub const WORDS: &[Word] = &[
         desc: "Execute quotation if false",
         example: "{ 1 distort } 0.5 chance !?",
         compile: Simple,
+        varargs: false,
     },
     // Sample playback
     Word {
@@ -845,6 +935,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set time offset",
         example: "0.1 time",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "repeat",
@@ -854,6 +945,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set repeat count",
         example: "4 repeat",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "dur",
@@ -863,6 +955,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set duration",
         example: "0.5 dur",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "gate",
@@ -872,6 +965,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set gate time",
         example: "0.8 gate",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "freq",
@@ -881,6 +975,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set frequency (Hz)",
         example: "440 freq",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "detune",
@@ -890,6 +985,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set detune amount",
         example: "0.01 detune",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "speed",
@@ -899,6 +995,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set playback speed",
         example: "1.5 speed",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "glide",
@@ -908,6 +1005,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set glide/portamento",
         example: "0.1 glide",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "pw",
@@ -917,6 +1015,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set pulse width",
         example: "0.5 pw",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "spread",
@@ -926,6 +1025,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set stereo spread",
         example: "0.5 spread",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "mult",
@@ -935,6 +1035,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set multiplier",
         example: "2 mult",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "warp",
@@ -944,6 +1045,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set warp amount",
         example: "0.5 warp",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "mirror",
@@ -953,6 +1055,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set mirror",
         example: "1 mirror",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "harmonics",
@@ -962,6 +1065,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set harmonics (mutable only)",
         example: "4 harmonics",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "timbre",
@@ -971,6 +1075,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set timbre (mutable only)",
         example: "0.5 timbre",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "morph",
@@ -980,6 +1085,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set morph (mutable only)",
         example: "0.5 morph",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "begin",
@@ -989,6 +1095,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set sample start (0-1)",
         example: "0.25 begin",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "end",
@@ -998,6 +1105,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set sample end (0-1)",
         example: "0.75 end",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "gain",
@@ -1007,6 +1115,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set volume (0-1)",
         example: "0.8 gain",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "postgain",
@@ -1016,6 +1125,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set post gain",
         example: "1.2 postgain",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "velocity",
@@ -1025,6 +1135,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set velocity",
         example: "100 velocity",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "pan",
@@ -1034,6 +1145,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set pan (-1 to 1)",
         example: "0.5 pan",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "attack",
@@ -1043,6 +1155,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set attack time",
         example: "0.01 attack",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "decay",
@@ -1052,6 +1165,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set decay time",
         example: "0.1 decay",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "sustain",
@@ -1061,6 +1175,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set sustain level",
         example: "0.5 sustain",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "release",
@@ -1070,6 +1185,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set release time",
         example: "0.3 release",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "adsr",
@@ -1079,6 +1195,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set attack, decay, sustain, release",
         example: "0.01 0.1 0.5 0.3 adsr",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "ad",
@@ -1088,6 +1205,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set attack, decay (sustain=0)",
         example: "0.01 0.1 ad",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: "lpf",
@@ -1097,6 +1215,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set lowpass frequency",
         example: "2000 lpf",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "lpq",
@@ -1106,6 +1225,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set lowpass resonance",
         example: "0.5 lpq",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "lpe",
@@ -1115,6 +1235,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set lowpass envelope",
         example: "0.5 lpe",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "lpa",
@@ -1124,6 +1245,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set lowpass attack",
         example: "0.01 lpa",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "lpd",
@@ -1133,6 +1255,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set lowpass decay",
         example: "0.1 lpd",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "lps",
@@ -1142,6 +1265,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set lowpass sustain",
         example: "0.5 lps",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "lpr",
@@ -1151,6 +1275,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set lowpass release",
         example: "0.3 lpr",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "hpf",
@@ -1160,6 +1285,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set highpass frequency",
         example: "100 hpf",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "hpq",
@@ -1169,6 +1295,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set highpass resonance",
         example: "0.5 hpq",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "hpe",
@@ -1178,6 +1305,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set highpass envelope",
         example: "0.5 hpe",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "hpa",
@@ -1187,6 +1315,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set highpass attack",
         example: "0.01 hpa",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "hpd",
@@ -1196,6 +1325,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set highpass decay",
         example: "0.1 hpd",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "hps",
@@ -1205,6 +1335,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set highpass sustain",
         example: "0.5 hps",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "hpr",
@@ -1214,6 +1345,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set highpass release",
         example: "0.3 hpr",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "bpf",
@@ -1223,6 +1355,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set bandpass frequency",
         example: "1000 bpf",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "bpq",
@@ -1232,6 +1365,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set bandpass resonance",
         example: "0.5 bpq",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "bpe",
@@ -1241,6 +1375,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set bandpass envelope",
         example: "0.5 bpe",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "bpa",
@@ -1250,6 +1385,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set bandpass attack",
         example: "0.01 bpa",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "bpd",
@@ -1259,6 +1395,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set bandpass decay",
         example: "0.1 bpd",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "bps",
@@ -1268,6 +1405,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set bandpass sustain",
         example: "0.5 bps",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "bpr",
@@ -1277,6 +1415,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set bandpass release",
         example: "0.3 bpr",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "llpf",
@@ -1286,6 +1425,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set ladder lowpass frequency",
         example: "2000 llpf",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "llpq",
@@ -1295,6 +1435,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set ladder lowpass resonance",
         example: "0.5 llpq",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "lhpf",
@@ -1304,6 +1445,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set ladder highpass frequency",
         example: "100 lhpf",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "lhpq",
@@ -1313,6 +1455,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set ladder highpass resonance",
         example: "0.5 lhpq",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "lbpf",
@@ -1322,6 +1465,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set ladder bandpass frequency",
         example: "1000 lbpf",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "lbpq",
@@ -1331,6 +1475,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set ladder bandpass resonance",
         example: "0.5 lbpq",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "ftype",
@@ -1340,6 +1485,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set filter type",
         example: "1 ftype",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "penv",
@@ -1349,6 +1495,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set pitch envelope",
         example: "0.5 penv",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "patt",
@@ -1358,6 +1505,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set pitch attack",
         example: "0.01 patt",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "pdec",
@@ -1367,6 +1515,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set pitch decay",
         example: "0.1 pdec",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "psus",
@@ -1376,6 +1525,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set pitch sustain",
         example: "0 psus",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "prel",
@@ -1385,6 +1535,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set pitch release",
         example: "0.1 prel",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "vib",
@@ -1394,6 +1545,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set vibrato rate",
         example: "5 vib",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "vibmod",
@@ -1403,6 +1555,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set vibrato depth",
         example: "0.5 vibmod",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "vibshape",
@@ -1412,6 +1565,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set vibrato shape",
         example: "0 vibshape",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "fm",
@@ -1421,6 +1575,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set FM frequency",
         example: "200 fm",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "fmh",
@@ -1430,6 +1585,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set FM harmonic ratio",
         example: "2 fmh",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "fmshape",
@@ -1439,6 +1595,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set FM shape",
         example: "0 fmshape",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "fme",
@@ -1448,6 +1605,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set FM envelope",
         example: "0.5 fme",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "fma",
@@ -1457,6 +1615,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set FM attack",
         example: "0.01 fma",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "fmd",
@@ -1466,6 +1625,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set FM decay",
         example: "0.1 fmd",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "fms",
@@ -1475,6 +1635,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set FM sustain",
         example: "0.5 fms",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "fmr",
@@ -1484,6 +1645,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set FM release",
         example: "0.1 fmr",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "am",
@@ -1493,6 +1655,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set AM frequency",
         example: "10 am",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "amdepth",
@@ -1502,6 +1665,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set AM depth",
         example: "0.5 amdepth",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "amshape",
@@ -1511,6 +1675,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set AM shape",
         example: "0 amshape",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "rm",
@@ -1520,6 +1685,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set RM frequency",
         example: "100 rm",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "rmdepth",
@@ -1529,6 +1695,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set RM depth",
         example: "0.5 rmdepth",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "rmshape",
@@ -1538,6 +1705,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set RM shape",
         example: "0 rmshape",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "phaser",
@@ -1547,6 +1715,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set phaser rate",
         example: "1 phaser",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "phaserdepth",
@@ -1556,6 +1725,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set phaser depth",
         example: "0.5 phaserdepth",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "phasersweep",
@@ -1565,6 +1735,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set phaser sweep",
         example: "0.5 phasersweep",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "phasercenter",
@@ -1574,6 +1745,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set phaser center",
         example: "1000 phasercenter",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "flanger",
@@ -1583,6 +1755,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set flanger rate",
         example: "0.5 flanger",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "flangerdepth",
@@ -1592,6 +1765,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set flanger depth",
         example: "0.5 flangerdepth",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "flangerfeedback",
@@ -1601,6 +1775,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set flanger feedback",
         example: "0.5 flangerfeedback",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "chorus",
@@ -1610,6 +1785,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set chorus rate",
         example: "1 chorus",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "chorusdepth",
@@ -1619,6 +1795,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set chorus depth",
         example: "0.5 chorusdepth",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "chorusdelay",
@@ -1628,6 +1805,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set chorus delay",
         example: "0.02 chorusdelay",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "eqlo",
@@ -1637,6 +1815,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set low shelf gain (dB)",
         example: "3 eqlo",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "eqmid",
@@ -1646,6 +1825,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set mid peak gain (dB)",
         example: "-2 eqmid",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "eqhi",
@@ -1655,6 +1835,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set high shelf gain (dB)",
         example: "1 eqhi",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "tilt",
@@ -1664,6 +1845,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set tilt EQ (-1 dark, 1 bright)",
         example: "-0.5 tilt",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "width",
@@ -1673,6 +1855,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set stereo width (0 mono, 1 normal, 2 wide)",
         example: "0 width",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "haas",
@@ -1682,6 +1865,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set Haas delay in ms (spatial placement)",
         example: "8 haas",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "comb",
@@ -1691,6 +1875,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set comb filter mix",
         example: "0.5 comb",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "combfreq",
@@ -1700,6 +1885,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set comb frequency",
         example: "200 combfreq",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "combfeedback",
@@ -1709,6 +1895,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set comb feedback",
         example: "0.5 combfeedback",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "combdamp",
@@ -1718,6 +1905,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set comb damping",
         example: "0.5 combdamp",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "coarse",
@@ -1727,6 +1915,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set coarse tune",
         example: "12 coarse",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "crush",
@@ -1736,6 +1925,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set bit crush",
         example: "8 crush",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "sub",
@@ -1745,6 +1935,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set sub oscillator level",
         example: "0.5 sub",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "suboct",
@@ -1754,6 +1945,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set sub oscillator octave",
         example: "2 suboct",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "subwave",
@@ -1763,6 +1955,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set sub oscillator waveform",
         example: "1 subwave",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "fold",
@@ -1772,6 +1965,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set wave fold",
         example: "2 fold",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "wrap",
@@ -1781,6 +1975,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set wave wrap",
         example: "0.5 wrap",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "distort",
@@ -1790,6 +1985,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set distortion",
         example: "0.5 distort",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "distortvol",
@@ -1799,6 +1995,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set distortion volume",
         example: "0.8 distortvol",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "delay",
@@ -1808,6 +2005,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set delay mix",
         example: "0.3 delay",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "delaytime",
@@ -1817,6 +2015,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set delay time",
         example: "0.25 delaytime",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "delayfeedback",
@@ -1826,6 +2025,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set delay feedback",
         example: "0.5 delayfeedback",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "delaytype",
@@ -1835,6 +2035,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set delay type",
         example: "1 delaytype",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "verb",
@@ -1844,6 +2045,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set reverb mix",
         example: "0.3 verb",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "verbdecay",
@@ -1853,6 +2055,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set reverb decay",
         example: "2 verbdecay",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "verbdamp",
@@ -1862,6 +2065,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set reverb damping",
         example: "0.5 verbdamp",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "verbpredelay",
@@ -1871,6 +2075,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set reverb predelay",
         example: "0.02 verbpredelay",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "verbdiff",
@@ -1880,6 +2085,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set reverb diffusion",
         example: "0.7 verbdiff",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "voice",
@@ -1889,6 +2095,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set voice number",
         example: "1 voice",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "orbit",
@@ -1898,6 +2105,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set orbit/bus",
         example: "0 orbit",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "note",
@@ -1907,6 +2115,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set MIDI note",
         example: "60 note",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "size",
@@ -1916,6 +2125,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set size",
         example: "1 size",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "n",
@@ -1925,6 +2135,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set sample number",
         example: "0 n",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "cut",
@@ -1934,6 +2145,7 @@ pub const WORDS: &[Word] = &[
         desc: "Set cut group",
         example: "1 cut",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "reset",
@@ -1943,6 +2155,7 @@ pub const WORDS: &[Word] = &[
         desc: "Reset parameter",
         example: "1 reset",
         compile: Param,
+        varargs: false,
     },
     Word {
         name: "clear",
@@ -1952,6 +2165,7 @@ pub const WORDS: &[Word] = &[
         desc: "Clear sound register (sound and all params)",
         example: "\"kick\" s 0.5 gain . clear \"hat\" s .",
         compile: Simple,
+        varargs: false,
     },
     // Quotation execution
     Word {
@@ -1962,6 +2176,7 @@ pub const WORDS: &[Word] = &[
         desc: "Execute quotation unconditionally",
         example: "{ 2 * } apply",
         compile: Simple,
+        varargs: false,
     },
     // Word definitions
     Word {
@@ -1972,6 +2187,7 @@ pub const WORDS: &[Word] = &[
         desc: "Begin word definition",
         example: ": kick \"kick\" s emit ;",
         compile: Simple,
+        varargs: false,
     },
     Word {
         name: ";",
@@ -1981,6 +2197,38 @@ pub const WORDS: &[Word] = &[
         desc: "End word definition",
         example: ": kick \"kick\" s emit ;",
         compile: Simple,
+        varargs: false,
+    },
+    // Generator
+    Word {
+        name: "..",
+        aliases: &[],
+        category: "Generator",
+        stack: "(start end -- start start+1 ... end)",
+        desc: "Push arithmetic sequence from start to end",
+        example: "1 4 .. => 1 2 3 4",
+        compile: Simple,
+        varargs: false,
+    },
+    Word {
+        name: "gen",
+        aliases: &[],
+        category: "Generator",
+        stack: "(quot n -- results...)",
+        desc: "Execute quotation n times, push all results",
+        example: "{ 1 6 rand } 4 gen => 4 random values",
+        compile: Simple,
+        varargs: true,
+    },
+    Word {
+        name: "geom..",
+        aliases: &[],
+        category: "Generator",
+        stack: "(start ratio count -- start start*r start*r^2 ...)",
+        desc: "Push geometric sequence",
+        example: "1 2 4 geom.. => 1 2 4 8",
+        compile: Simple,
+        varargs: false,
     },
 ];
 
@@ -2056,6 +2304,9 @@ pub(super) fn simple_op(name: &str) -> Option<Op> {
         "oct" => Op::Oct,
         ".!" => Op::EmitN,
         "clear" => Op::ClearCmd,
+        ".." => Op::IntRange,
+        "gen" => Op::Generate,
+        "geom.." => Op::GeomRange,
         _ => return None,
     })
 }
diff --git a/crates/ratatui/src/scope.rs b/crates/ratatui/src/scope.rs
index 93140ea..712d44f 100644
--- a/crates/ratatui/src/scope.rs
+++ b/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);
+                }
             }
         }
-    }
+    });
 }
diff --git a/src/engine/audio.rs b/src/engine/audio.rs
index 7afe59b..0e921ee 100644
--- a/src/engine/audio.rs
+++ b/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();
diff --git a/src/engine/sequencer.rs b/src/engine/sequencer.rs
index dbc100b..a3275b9 100644
--- a/src/engine/sequencer.rs
+++ b/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,
         }
@@ -366,7 +368,6 @@ pub(crate) struct TickOutput {
 }
 
 struct StepResult {
-    audio_commands: Vec<String>,
     completed_iterations: Vec<PatternId>,
     any_step_fired: bool,
 }
@@ -384,15 +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 {
@@ -406,11 +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(),
         }
     }
 
@@ -459,7 +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 => {}
@@ -491,7 +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(),
         }
@@ -500,13 +533,14 @@ 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.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(),
         }
@@ -547,7 +581,7 @@ 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);
@@ -565,32 +599,29 @@ 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());
@@ -634,13 +665,13 @@ 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);
                                 }
                             }
                         }
@@ -681,18 +712,18 @@ 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 {
@@ -738,7 +769,7 @@ 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,
         }
diff --git a/src/input.rs b/src/input.rs
index b9f38e7..62b841e 100644
--- a/src/input.rs
+++ b/src/input.rs
@@ -476,7 +476,7 @@ fn handle_modal_input(ctx: &mut InputContext, key: KeyEvent) -> InputResult {
                 KeyCode::Char('p') if ctrl => {
                     editor.search_prev();
                 }
-                KeyCode::Char('k') if ctrl => {
+                KeyCode::Char('s') if ctrl => {
                     ctx.app.editor_ctx.show_stack = !ctx.app.editor_ctx.show_stack;
                 }
                 KeyCode::Char('a') if ctrl => {
diff --git a/src/state/editor.rs b/src/state/editor.rs
index b9d26f0..125941b 100644
--- a/src/state/editor.rs
+++ b/src/state/editor.rs
@@ -1,3 +1,4 @@
+use std::cell::RefCell;
 use std::ops::RangeInclusive;
 
 use cagire_ratatui::Editor;
@@ -55,6 +56,14 @@ pub struct EditorContext {
     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)]
@@ -96,6 +105,7 @@ impl Default for EditorContext {
             selection_anchor: None,
             copied_steps: None,
             show_stack: false,
+            stack_cache: RefCell::new(None),
         }
     }
 }
diff --git a/src/state/mod.rs b/src/state/mod.rs
index d1f6a48..acc19e2 100644
--- a/src/state/mod.rs
+++ b/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};
diff --git a/src/views/highlight.rs b/src/views/highlight.rs
index d178c81..a6e6af3 100644
--- a/src/views/highlight.rs
+++ b/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
@@ -98,11 +152,11 @@ pub fn tokenize_line(line: &str) -> Vec<Token> {
         }
 
         if c == ';' && chars.peek().map(|(_, ch)| *ch) == Some(';') {
-            // ;; starts a comment to end of line
             tokens.push(Token {
                 start,
                 end: line.len(),
                 kind: TokenKind::Comment,
+                varargs: false,
             });
             break;
         }
@@ -119,6 +173,7 @@ pub fn tokenize_line(line: &str) -> Vec<Token> {
                 start,
                 end,
                 kind: TokenKind::String,
+                varargs: false,
             });
             continue;
         }
@@ -133,35 +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)> {
@@ -179,13 +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
@@ -196,6 +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 {
@@ -207,7 +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
diff --git a/src/views/render.rs b/src/views/render.rs
index 1e91632..1162e17 100644
--- a/src/views/render.rs
+++ b/src/views/render.rs
@@ -1,4 +1,6 @@
+use std::collections::hash_map::DefaultHasher;
 use std::collections::HashMap;
+use std::hash::{Hash, Hasher};
 use std::sync::{Arc, Mutex};
 use std::time::Instant;
 
@@ -15,7 +17,7 @@ use crate::app::App;
 use crate::engine::{LinkState, SequencerSnapshot};
 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,
@@ -25,43 +27,67 @@ 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) -> String {
+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");
 
-    if script.trim().is_empty() {
-        return "Stack: []".to_string();
-    }
+    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 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,
+        };
 
-    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}"),
+        }
     };
 
-    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 {
@@ -740,13 +766,13 @@ fn render_modal(frame: &mut Frame, app: &App, snapshot: &SequencerSnapshot, term
                 ]);
                 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);
+                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-k", key),
+                    Span::styled("C-s", key),
                     Span::styled(" hide", dim),
                 ]);
                 let [hint_left, stack_right] = Layout::horizontal([
@@ -767,7 +793,7 @@ fn render_modal(frame: &mut Frame, app: &App, snapshot: &SequencerSnapshot, term
                     Span::styled(" eval  ", dim),
                     Span::styled("C-f", key),
                     Span::styled(" find  ", dim),
-                    Span::styled("C-k", key),
+                    Span::styled("C-s", key),
                     Span::styled(" stack  ", dim),
                     Span::styled("C-u", key),
                     Span::styled("/", dim),
diff --git a/tests/forth.rs b/tests/forth.rs
index 36d7df1..91c9ccb 100644
--- a/tests/forth.rs
+++ b/tests/forth.rs
@@ -48,3 +48,6 @@ mod list_words;
 
 #[path = "forth/ramps.rs"]
 mod ramps;
+
+#[path = "forth/generator.rs"]
+mod generator;
diff --git a/tests/forth/generator.rs b/tests/forth/generator.rs
new file mode 100644
index 0000000..8dc3b97
--- /dev/null
+++ b/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");
+}