Use order instead of operator to normalize infix expressions

[fur] / parsing.py

diff --git a/parsing.py b/parsing.py
index 5a88fdc..23bf65e 100644 (file)
--- a/parsing.py
+++ b/parsing.py
@@ -1,5 +1,11 @@
 import collections
 
+def consume_newlines(index, tokens):
+    while index < len(tokens) and tokens[index].type == 'newline':
+        index += 1
+
+    return True, index, None
+
 def _or_parser(*parsers):
     def result_parser(index, tokens):
         failure = (False, index, None)
@@ -184,17 +190,17 @@ def _addition_level_expression_parser(index, tokens):
         'addition_level',
     )(index, tokens)
 
-def _equality_level_expression_parser(index, tokens):
+def _comparison_level_expression_parser(index, tokens):
     return _left_recursive_infix_operator_parser(
-        lambda token: token.type == 'equality_level_operator',
+        lambda token: token.type == 'comparison_level_operator',
         _addition_level_expression_parser,
-        'equality_level',
+        'comparison_level',
     )(index, tokens)
 
 def _and_level_expression_parser(index, tokens):
     return _left_recursive_infix_operator_parser(
         lambda token: token.type == 'symbol' and token.match == 'and',
-        _equality_level_expression_parser,
+        _comparison_level_expression_parser,
         'and_level',
     )(index, tokens)
 
@@ -238,6 +244,13 @@ FurFunctionCallExpression = collections.namedtuple(
     ],
 )
 
+FurExpressionStatement = collections.namedtuple(
+    'FurExpressionStatement',
+    [
+        'expression',
+    ],
+)
+
 FurAssignmentStatement = collections.namedtuple(
     'FurAssignmentStatement',
     [
@@ -282,6 +295,16 @@ def _function_call_expression_parser(index, tokens):
 
 _expression_parser = _or_level_expression_parser
 
+def _expression_statement_parser(index, tokens):
+    failure = (False, index, None)
+
+    success, index, expression = _expression_parser(index, tokens)
+
+    if not success:
+        return failure
+
+    return (True, index, FurExpressionStatement(expression=expression))
+
 def _assignment_statement_parser(index, tokens):
     # TODO Use a FurSymbolExpression for the target? Maybe this is actually not a good idea
     failure = (False, index, None)
@@ -307,10 +330,14 @@ def _assignment_statement_parser(index, tokens):
     return True, index, FurAssignmentStatement(target=target, expression=expression)
 
 def _statement_parser(index, tokens):
-    # TODO It would be good to include newlines in the parsing of this because it removes the ambiguity between "function(argument)" (one statement) and "function\n(argument)" (two statements)
+    _, index, _ = consume_newlines(index, tokens)
+
+    if index == len(tokens):
+        return (False, index, None)
+
     return _or_parser(
         _assignment_statement_parser,
-        _expression_parser,
+        _expression_statement_parser,
     )(index, tokens)
 
 def _program_formatter(statement_list):