From 208706fb52436b99341c384e5a5ee5068c6c3547 Mon Sep 17 00:00:00 2001
From: Felix Roos <flix91@gmail.com>
Date: Thu, 20 Mar 2025 09:09:29 +0100
Subject: [PATCH] simplify mondo: ":" is just another operator

---
 packages/mondo/mondo.mjs           | 42 +++++-------------------------
 packages/mondo/test/mondo.test.mjs |  1 +
 2 files changed, 8 insertions(+), 35 deletions(-)

diff --git a/packages/mondo/mondo.mjs b/packages/mondo/mondo.mjs
index fc4069434..5997feb40 100644
--- a/packages/mondo/mondo.mjs
+++ b/packages/mondo/mondo.mjs
@@ -19,8 +19,7 @@ export class MondoParser {
     number: /^-?[0-9]*\.?[0-9]+/, // before pipe!
     pipe: /^\./,
     stack: /^[,$]/,
-    op: /^[*/]/,
-    tail: /^:/,
+    op: /^[*/:]/,
     plain: /^[a-zA-Z0-9-~_^]+/,
   };
   // matches next token
@@ -97,7 +96,6 @@ export class MondoParser {
     return this.consume(next);
   }
   desugar_children(children) {
-    children = this.resolve_tails(children);
     children = this.resolve_ops(children);
     children = this.resolve_pipes(children);
     return children;
@@ -146,32 +144,10 @@ export class MondoParser {
     });
     return [{ type: 'plain', value: 'stack' }, ...args];
   }
-  resolve_tails(children) {
-    while (true) {
-      let opIndex = children.findIndex((child) => child.type === 'tail');
-      if (opIndex === -1) break;
-      const op = { type: 'plain', value: children[opIndex].value };
-      if (opIndex === children.length - 1) {
-        throw new Error(`cannot use operator as last child.`);
-      }
-      if (opIndex === 0) {
-        // regular function call (assuming each operator exists as function)
-        children[opIndex] = op;
-        continue;
-      }
-      const left = children[opIndex - 1];
-      const right = children[opIndex + 1];
-
-      // convert infix to prefix notation
-      const call = { type: 'list', children: [op, left, right] };
-
-      // insert call while keeping other siblings
-      children = [...children.slice(0, opIndex - 1), call, ...children.slice(opIndex + 2)];
-      // unwrap double list.. e.g. (s jazz) * 2
-      if (children.length === 1) {
-        // there might be a cleaner solution
-        children = children[0].children;
-      }
+  // prevents to get a list, e.g. ((x y)) => (x y)
+  unwrap_children(children) {
+    if (children.length === 1) {
+      return children[0].children;
     }
     return children;
   }
@@ -188,6 +164,7 @@ export class MondoParser {
         children[opIndex] = op;
         continue;
       }
+      // convert infix to prefix notation
       const left = children[opIndex - 1];
       const right = children[opIndex + 1];
       if (left.type === 'pipe') {
@@ -195,15 +172,10 @@ export class MondoParser {
         children[opIndex] = op;
         continue;
       }
-      // convert infix to prefix notation
       const call = { type: 'list', children: [op, left, right] };
       // insert call while keeping other siblings
       children = [...children.slice(0, opIndex - 1), call, ...children.slice(opIndex + 2)];
-      // unwrap double list.. e.g. (s jazz) * 2
-      if (children.length === 1) {
-        // there might be a cleaner solution
-        children = children[0].children;
-      }
+      children = this.unwrap_children(children);
     }
     return children;
   }
diff --git a/packages/mondo/test/mondo.test.mjs b/packages/mondo/test/mondo.test.mjs
index c78712e9d..e21ec75b0 100644
--- a/packages/mondo/test/mondo.test.mjs
+++ b/packages/mondo/test/mondo.test.mjs
@@ -101,6 +101,7 @@ describe('mondo sugar', () => {
   it('should desugar []*x', () => expect(desguar('[a [b c]*3]')).toEqual('(seq a (* (seq b c) 3))'));
   it('should desugar x:y', () => expect(desguar('x:y')).toEqual('(: x y)'));
   it('should desugar x:y:z', () => expect(desguar('x:y:z')).toEqual('(: (: x y) z)'));
+  it('should desugar x:y*x', () => expect(desguar('bd:0*2')).toEqual('(* (: bd 0) 2)'));
 
   it('should desugar README example', () =>
     expect(desguar('s [bd hh*2 cp.(crush 4) <mt ht lt>] . speed .8')).toEqual(