Feat: Add list list comprehension to demo.

Author: dylan-sutton-chavez

compiler/README.md

@@ -142,10 +142,13 @@ cargo test --features wasm-tests
 3. Cytron, Ferrante, Rosen, Wegman & Zadeck, *Efficiently Computing Static Single Assignment Form* (TOPLAS 1991). SSA, $\phi$-nodes.
 4. Gudeman, *Representing Type Information in Dynamically Typed Languages* (1993). NaN-boxing.
 5. Deutsch & Schiffman, *Efficient Implementation of the Smalltalk-80 System* (POPL 1984). Inline caching.
-6. Hölzle & Ungar, *Optimizing Dynamically-Dispatched Calls with Run-Time Type Feedback* (PLDI 1994). Adaptive rewriting.
-7. Michie, *Memo Functions and Machine Learning* (Nature 1968). Memoization.
-8. McCarthy, *Recursive Functions of Symbolic Expressions* (CACM 1960). Mark-sweep garbage collector.
-9. Shannon, PEP 659: *Specializing Adaptive Interpreter* (2021). Tiered specialization.
+6. Ertl & Gregg, *The Structure and Performance of Efficient Interpreters* (JILP 2003). Bytecode dispatch, superinstructions.
+7. Hölzle & Ungar, *Optimizing Dynamically-Dispatched Calls with Run-Time Type Feedback* (PLDI 1994). Adaptive rewriting.
+8. Michie, *Memo Functions and Machine Learning* (Nature 1968). Memoization.
+9. McCarthy, *Recursive Functions of Symbolic Expressions* (CACM 1960). Mark-sweep garbage collector.
+10. Knuth, *The Art of Computer Programming, Vol. 2: Seminumerical Algorithms* (1981). Arbitrary-precision arithmetic, §4.3.
+11. Shannon, PEP 659: *Specializing Adaptive Interpreter* (2021). Tiered specialization.
+12. O'Connor, PEP 709: *Inlined Comprehensions* (2023). Drain-and-reinject compilation.
 
 ### License
 

compiler/src/modules/parser/control.rs

@@ -188,12 +188,12 @@ impl<'src, I: Iterator<Item = Token>> Parser<'src, I> {
             let before = sp as u16;
             let after  = (vars.len() - sp - 1) as u16;
             self.chunk.emit(OpCode::UnpackEx, (before << 8) | after);
-            for var in vars.iter().rev() {
+            for var in &vars {
                 self.store_name(var.clone());
             }
         } else {
             self.chunk.emit(OpCode::UnpackSequence, vars.len() as u16);
-            for var in vars.iter().rev() {
+            for var in &vars {
                 self.store_name(var.clone());
             }
         }

compiler/src/modules/parser/literals.rs

@@ -130,7 +130,7 @@ impl<'src, I: Iterator<Item = Token>> Parser<'src, I> {
                 self.store_name(vars[0].clone());
             } else {
                 self.chunk.emit(OpCode::UnpackSequence, vars.len() as u16);
-                for var in vars.iter().rev() {
+                for var in &vars {
                     self.store_name(var.clone());
                 }
             }

compiler/src/modules/parser/stmt.rs

@@ -195,7 +195,7 @@ impl<'src, I: Iterator<Item = Token>> Parser<'src, I> {
                 self.expr();
                 let after = (targets.len() - 1) as u16;
                 self.chunk.emit(OpCode::UnpackEx, after);
-                for target in targets.into_iter().rev() {
+                for target in targets {
                     self.store_name(target.trim_start_matches('*').to_string());
                 }
                 false
@@ -408,7 +408,7 @@ impl<'src, I: Iterator<Item = Token>> Parser<'src, I> {
                     } else {
                         self.chunk.emit(OpCode::UnpackSequence, targets.len() as u16);
                     }
-                    for target in targets.into_iter().rev() {
+                    for target in targets {
                         self.store_name(target.trim_start_matches('*').to_string());
                     }
                     false

compiler/src/modules/vm/builtins.rs

@@ -14,8 +14,7 @@ impl<'a> VM<'a> {
     */
 
     pub fn call_print(&mut self, op: u16) -> Result<(), VmErr> {
-        let mut args = self.pop_n(op as usize)?;
-        args.reverse();
+        let args = self.pop_n(op as usize)?;
         let s = args.iter().map(|v| self.display(*v)).collect::<Vec<_>>().join(" ");
         self.output.push(s);
         Ok(())

compiler/tests/cases/parser_cases.json

@@ -668,14 +668,14 @@
   {
     "src": "a, b = 1, 2", 
     "constants": ["1", "2"], 
-    "names": ["b_1", "a_1"], 
+    "names": ["a_1", "b_1"], 
     "instructions": [["LoadConst",0], ["LoadConst",1], ["BuildTuple",2], ["UnpackSequence",2], ["StoreName",0], ["StoreName",1], ["ReturnValue",0]], 
     "annotations": {}
   },
   {
     "src": "a, b, c = 1, 2, 3", 
     "constants": ["1", "2", "3"], 
-    "names": ["c_1", "b_1", "a_1"], 
+    "names": ["a_1", "b_1", "c_1"], 
     "instructions": [["LoadConst",0], ["LoadConst",1], ["LoadConst",2], ["BuildTuple",3], ["UnpackSequence",3], ["StoreName",0], ["StoreName",1], ["StoreName",2], ["ReturnValue",0]], 
     "annotations": {}
   },
@@ -988,21 +988,21 @@
   {
     "src": "*a, b = [1, 2, 3]", 
     "constants": ["1", "2", "3"], 
-    "names": ["b_1", "a_1"], 
+    "names": ["a_1", "b_1"], 
     "instructions": [["LoadConst",0], ["LoadConst",1], ["LoadConst",2], ["BuildList",3], ["UnpackEx",1], ["StoreName",0], ["StoreName",1], ["ReturnValue",0]], 
     "annotations": {}
   },
   {
     "src": "a, *b = [1, 2, 3]", 
     "constants": ["1", "2", "3"], 
-    "names": ["b_1", "a_1"], 
+    "names": ["a_1", "b_1"], 
     "instructions": [["LoadConst",0], ["LoadConst",1], ["LoadConst",2], ["BuildList",3], ["UnpackEx",256], ["StoreName",0], ["StoreName",1], ["ReturnValue",0]], 
     "annotations": {}
   },
   {
     "src": "a, *b, c = [1, 2, 3, 4]", 
     "constants": ["1", "2", "3", "4"], 
-    "names": ["c_1", "b_1", "a_1"], 
+    "names": ["a_1", "b_1", "c_1"], 
     "instructions": [["LoadConst",0], ["LoadConst",1], ["LoadConst",2], ["LoadConst",3], ["BuildList",4], ["UnpackEx",257], ["StoreName",0], ["StoreName",1], ["StoreName",2], ["ReturnValue",0]], 
     "annotations": {}
   },
@@ -1095,14 +1095,14 @@
   {
     "src": "for a, b in x:\n    pass", 
     "constants": [], 
-    "names": ["x_0", "b_1", "a_1", "a_0", "a_2", "b_0", "b_2"], 
+    "names": ["x_0", "a_1", "b_1", "a_0", "a_2", "b_0", "b_2"], 
     "instructions": [["LoadName",0], ["GetIter",0], ["ForIter",7], ["UnpackSequence",2], ["StoreName",1], ["StoreName",2], ["Jump",2], ["Phi",4], ["Phi",6], ["ReturnValue",0]], 
     "annotations": {}
   },
   {
     "src": "for a, b, c in x:\n    pass", 
     "constants": [], 
-    "names": ["x_0", "c_1", "b_1", "a_1", "a_0", "a_2", "b_0", "b_2", "c_0", "c_2"], 
+    "names": ["x_0", "a_1", "b_1", "c_1", "a_0", "a_2", "b_0", "b_2", "c_0", "c_2"], 
     "instructions": [["LoadName",0], ["GetIter",0], ["ForIter",8], ["UnpackSequence",3], ["StoreName",1], ["StoreName",2], ["StoreName",3], ["Jump",2], ["Phi",5], ["Phi",7], ["Phi",9], ["ReturnValue",0]], 
     "annotations": {}
   },
@@ -1155,14 +1155,14 @@
   {
     "src": "for (a, b) in x:\n    pass", 
     "constants": [], 
-    "names": ["x_0", "b_1", "a_1", "a_0", "a_2", "b_0", "b_2"], 
+    "names": ["x_0", "a_1", "b_1", "a_0", "a_2", "b_0", "b_2"], 
     "instructions": [["LoadName",0], ["GetIter",0], ["ForIter",7], ["UnpackSequence",2], ["StoreName",1], ["StoreName",2], ["Jump",2], ["Phi",4], ["Phi",6], ["ReturnValue",0]], 
     "annotations": {}
   },
   {
     "src": "for a, *b in x:\n    pass", 
     "constants": [], 
-    "names": ["x_0", "b_1", "a_1", "a_0", "a_2", "b_0", "b_2"], 
+    "names": ["x_0", "a_1", "b_1", "a_0", "a_2", "b_0", "b_2"], 
     "instructions": [["LoadName",0], ["GetIter",0], ["ForIter",7], ["UnpackEx",256], ["StoreName",1], ["StoreName",2], ["Jump",2], ["Phi",4], ["Phi",6], ["ReturnValue",0]], 
     "annotations": {}
   },
@@ -1543,10 +1543,10 @@
   {
     "src": "x = {k: v for k, v in items}",
     "constants": [],
-    "names": ["k_0", "v_0", "items_0", "v_1", "k_1", "x_1"],
-    "instructions": [["BuildDict",0], ["LoadName",2], ["GetIter",0], ["ForIter",11], ["UnpackSequence",2], ["StoreName",3], ["StoreName",4], ["LoadName",4], ["LoadName",3], ["MapAdd",0], ["Jump",3], ["StoreName",5], ["ReturnValue",0]],
+    "names": ["k_0", "v_0", "items_0", "k_1", "v_1", "x_1"],
+    "instructions": [["BuildDict",0], ["LoadName",2], ["GetIter",0], ["ForIter",11], ["UnpackSequence",2], ["StoreName",3], ["StoreName",4], ["LoadName",3], ["LoadName",4], ["MapAdd",0], ["Jump",3], ["StoreName",5], ["ReturnValue",0]],
     "annotations": {}
-  }
+  },
   {
     "src": "a[0] = 1", 
     "constants": ["0","1"], 

demo/main.js

@@ -13,7 +13,7 @@ const WASM_SOURCES = DEV
     ? [`https://demo.edgepython.com/compiler_lib.wasm${_bust}`]
     : [`./compiler_lib.wasm${_bust}`];
 
-const DEFAULT_CODE = `"""\nImplements a pure functional pipeline using head-tail recursion to avoid state mutation.\n\nReferences:\n* Backus, J. (1978). Algebra of Programs (Function composition).\n"""\n\ndef double(n: int) -> int:\n    return n * 2\n\ndef square(n: int) -> int:\n    return n * n\n\ndef apply_pipeline(value: int, steps: list[int]) -> int:\n    # Stop recursion when no steps remain\n    if not steps:\n        return value\n\n    first_fn = steps[0]\n    remaining_steps = steps[1:]\n\n    return apply_pipeline(first_fn(value), remaining_steps)\n\ndef transform_list(elements: list[int], steps: list[int]) -> list[int]:\n    # Stop recursion when list is empty\n    if not elements:\n        return []\n\n    head = elements[0]\n    tail = elements[1:]\n\n    transformed = apply_pipeline(head, steps)\n\n    return [transformed] + transform_list(tail, steps)\n\ndata: list[int] = [1, 2, 3]\npipeline: list = [double, square]\n\nresult = transform_list(data, pipeline)\n\nprint(f"Input: {data}")\nprint(f"Output: {result}")`;
+const DEFAULT_CODE = `"""\nImplements a functional pipeline using function composition and list comprehensions.\nReferences: Backus, J. (1978).\n"""\n\ndef double(n: int) -> int:\n    return n * 2\n\ndef square(n: int) -> int:\n    return n * n\n\ndef apply_pipeline(value: int, steps: list) -> int:\n    # Stop recursion when no steps remain\n    if not steps:\n        return value\n\n    first_fn = steps[0]\n    remaining_steps = steps[1:]\n\n    return apply_pipeline(first_fn(value), remaining_steps)\n\ndata: list[int] = [1, 2, 3]\npipeline: list = [double, square]\n\nresult = [apply_pipeline(x, pipeline) for x in data] # Stop recursion when list is empty\n\nprint(f"Input: {data}")\nprint(f"Output: {result}")`;
 
 const CLS = { ok: 'ml-auto text-[#7daf7a]', err: 'ml-auto text-[#d67f6d]' };
 const MAX_LINES = 99;