[WIP] Syntax Recovery

README.md

@@ -4,7 +4,7 @@
 [![Coverage Status](https://coveralls.io/repos/github/jdpage/jeff65/badge.svg?branch=master)](https://coveralls.io/github/jdpage/jeff65?branch=master)
 
 *jeff65* is a compiler for the Commodore 64 (and perhaps in the future, other
-6502-based computers). It is implemented in Python 3 and produces .prg files
+6502-based computers). It is implemented in Python 3.6 (or newer) and produces .prg files
 which can be loaded directly in VICE, or combined into .d64 disk images, written
 to a floppy disk, and run on real hardware.
 
@@ -26,6 +26,16 @@ Invocation:
       -h, --help  show this help message and exit
 
 
+## Status
+
+* Basic syntax definition: finished, needs formal documentation.
+* Lexer / Tokenizer: finished.
+* Stage 1 Parsing (AST Generation): 75% finished.
+* Stage 2 Parsing (AST validation and traversal): 15% finished.
+* Stage 3 Parsing (AST optimization): not planned (for now).
+* 6502 ASM Code Generation: not yet begun.
+
+
 ## Licensing
 
 The *jeff65* compiler itself is provided under the GPLv3 license; if you

jeff65/gold/compiler.py

@@ -58,6 +58,19 @@ def parse(fileobj, name):
     return builder.ast
 
 
+def parse_expr(fileobj, name):
+    lexer = Lexer(fileobj, name=name)
+    tokens = antlr4.CommonTokenStream(lexer)
+    parser = Parser(tokens)
+    tree = parser.expr()
+    if parser._syntaxErrors > 0:
+        raise ast.ParseError("Unit {} had errors; terminating".format(name))
+    builder = ast.AstBuilder()
+    builder._push(ast.AstNode('<expr>', (0, 0)))
+    antlr4.ParseTreeWalker.DEFAULT.walk(builder, tree)
+    return builder.ast
+
+
 def translate(unit, verbose=False):
     with open_unit(unit) as input_file:
         obj = parse(input_file, name=unit.name)

requirements.txt

@@ -1,4 +1,5 @@
 nose==1.3.7
+coverage==4.4.2
 flake8==3.5.0
 coverage==4.5.1
 antlr4-python3-runtime==4.5.2