Implements __alloc_bytes__, uses it in the buffer example

Also, updated todo, remove broken code from buffer example

Makefile

@@ -3,7 +3,7 @@ WABT_DIR := /home/johan/Sources/github.com/WebAssembly/wabt
 WAT2WASM := $(WABT_DIR)/bin/wat2wasm
 WASM2C := $(WABT_DIR)/bin/wasm2c
 
-%.wat: %.py phasm/*.py venv/.done
+%.wat: %.py $(shell find phasm -name '*.py') venv/.done
 	venv/bin/python -m phasm $< $@
 
 %.wat.html: %.wat

TODO.md

@@ -1,6 +1,5 @@
 # TODO
 
-- Rename ourlang.Struct to OurTypeStruct
-  - Maybe rename this to a types module?
-- Fix naming in Suite() calls
+- Implement foldl for bytes
 - Replace ___new_reference___ by stdlib.alloc.__alloc__
+- Implement a trace() builtin for debugging

examples/buffer.html

@@ -30,22 +30,20 @@ WebAssembly.instantiateStreaming(fetch('buffer.wasm'), importObject)
     // Allocate room within the memory of the WebAssembly class
     let size = 8;
 
-    // TODO: Use bytes constructor
-    let offset = app.instance.exports.___new_reference___(size);
-    new Uint32Array(app.instance.exports.memory.buffer, offset, 1)[0] = size;
+    stdlib_alloc___init__ = app.instance.exports['stdlib.alloc.__init__']
+    stdlib_alloc___init__()
+
+    stdlib_types___alloc_bytes__ = app.instance.exports['stdlib.types.__alloc_bytes__']
+
+    let offset = stdlib_types___alloc_bytes__(size)
     var i8arr = new Uint8Array(app.instance.exports.memory.buffer, offset + 4, size);
 
     //Fill it
-    let sum = 0;
     for (var i = 0; i < size; i++) {
       i8arr[i] = i + 5;
-      sum += i8arr[i];
       let from_wasm = app.instance.exports.index(offset, i);
       log('i8arr[' + i + '] = ' + from_wasm);
     }
-
-    log('expected result = ' + sum);
-    log('actual result = ' + app.instance.exports.sum(offset));
   });
 </script>
 

examples/buffer.py

@@ -1,7 +1,3 @@
-@exported
-def sum() -> i32: # TODO: Should be [i32] -> i32
-    return 0 # TODO: Implement me
-
 @exported
 def index(inp: bytes, idx: i32) -> i32:
     return inp[idx]

phasm/compiler.py

@@ -6,9 +6,9 @@ from typing import Generator
 from . import ourlang
 from . import typing
 from . import wasm
-from . import wasmeasy
 
 from .stdlib import alloc as stdlib_alloc
+from .stdlib import types as stdlib_types
 from .wasmeasy import i32, i64
 
 Statements = Generator[wasm.Statement, None, None]
@@ -380,6 +380,7 @@ def module(inp: ourlang.Module) -> wasm.Module:
         stdlib_alloc.__init__,
         stdlib_alloc.__find_free_block__,
         stdlib_alloc.__alloc__,
+        stdlib_types.__alloc_bytes__,
         _generate____access_bytes_index___(inp),
     ] + [
         function(x)

phasm/stdlib/types.py

@@ -0,0 +1,32 @@
+"""
+stdlib: Standard types that are not wasm primitives
+"""
+from phasm.wasmgenerator import Generator, VarType_i32 as i32, func_wrapper
+
+from phasm.stdlib import alloc
+
+@func_wrapper()
+def __alloc_bytes__(g: Generator, length: i32) -> i32:
+    """
+    Allocates room for a bytes instance, but does not write
+    anything to the allocated memory
+    """
+    result = i32('result')
+
+    # Allocate the length of the byte string, as well
+    # as 4 bytes for a length header
+    g.local.get(length)
+    g.i32.const(4)
+    g.i32.add()
+    g.call(alloc.__alloc__)
+
+    # Store the address in a variable so we can use it up
+    # for writing the length header
+    g.local.tee(result)
+    g.local.get(length)
+    g.i32.store()
+
+    # Get the address back from the variable as return
+    g.local.get(result)
+
+    return i32('return') # To satisfy mypy