chain word and better save/load UI

crates/forth/src/words.rs

@@ -428,6 +428,13 @@ pub const WORDS: &[Word] = &[
         example: "pattern => 0",
         compile: Context("pattern"),
     },
+    Word {
+        name: "pbank",
+        stack: "(-- n)",
+        desc: "Current pattern's bank index",
+        example: "pbank => 0",
+        compile: Context("bank"),
+    },
     Word {
         name: "tempo",
         stack: "(-- f)",
@@ -621,6 +628,13 @@ pub const WORDS: &[Word] = &[
         example: "140 tempo!",
         compile: Simple,
     },
+    Word {
+        name: "chain",
+        stack: "(bank pattern --)",
+        desc: "Chain to bank/pattern (1-indexed) when current pattern ends",
+        example: "1 4 chain",
+        compile: Simple,
+    },
     // Lists
     Word {
         name: "[",
@@ -1550,6 +1564,7 @@ pub(super) fn simple_op(name: &str) -> Option<Op> {
         "ramp" => Op::Ramp,
         "range" => Op::Range,
         "noise" => Op::Noise,
+        "chain" => Op::Chain,
         _ => return None,
     })
 }