X-Git-Url: https://code.kerkeslager.com/?a=blobdiff_plain;f=parsing.py;h=041f3aa8e0f893072e191328f58e457b0f33a2e4;hb=059e6ff380d17a715ffbd2d55ac59e39c931a954;hp=a7dd838f08a17c8a7e98b9332c9342080fdd597c;hpb=730c0a3faa442985f6fdb73d91a1e6b9f72e6165;p=fur

diff --git a/parsing.py b/parsing.py
index a7dd838..041f3aa 100644
--- a/parsing.py
+++ b/parsing.py
@@ -64,6 +64,7 @@ FurNegationExpression = collections.namedtuple(
     ],
 )
 
+# TODO We don't need to wrap this type
 FurParenthesizedExpression = collections.namedtuple(
     'FurParenthesizedExpression',
     [
@@ -190,17 +191,17 @@ 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)
 
@@ -212,7 +213,7 @@ def _or_level_expression_parser(index, tokens):
     )(index, tokens)
 
 def _comma_separated_list_parser(index, tokens):
-    failure = (False, index, None)
+    start_index = index
 
     expressions = []
 
@@ -221,7 +222,7 @@ def _comma_separated_list_parser(index, tokens):
     if success:
         expressions.append(expression)
     else:
-        return failure
+        return (True, start_index, ())
 
     while success and index < len(tokens) and tokens[index].type == 'comma':
         success = False
@@ -244,6 +245,13 @@ FurFunctionCallExpression = collections.namedtuple(
     ],
 )
 
+FurExpressionStatement = collections.namedtuple(
+    'FurExpressionStatement',
+    [
+        'expression',
+    ],
+)
+
 FurAssignmentStatement = collections.namedtuple(
     'FurAssignmentStatement',
     [
@@ -252,6 +260,14 @@ FurAssignmentStatement = collections.namedtuple(
     ],
 )
 
+FurFunctionDefinitionStatement = collections.namedtuple(
+    'FurFunctionDefinitionStatement',
+    [
+        'name',
+        'statement_list',
+    ],
+)
+
 FurProgram = collections.namedtuple(
     'FurProgram',
     [
@@ -288,6 +304,16 @@ 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)
@@ -312,6 +338,55 @@ def _assignment_statement_parser(index, tokens):
 
     return True, index, FurAssignmentStatement(target=target, expression=expression)
 
+def _function_definition_statement_parser(index, tokens):
+    failure = (False, index, None)
+
+    if tokens[index].type == 'keyword' and tokens[index].match == 'def':
+        index += 1
+    else:
+        return failure
+
+    if tokens[index].type == 'symbol':
+        name = tokens[index].match
+        index += 1
+    else:
+        raise Exception('Expected function name, found "{}" on line {}'.format(
+            tokens[index].match,
+            tokens[index].line,
+        ))
+
+    if tokens[index].type == 'open_parenthese':
+        index += 1
+    else:
+        raise Exception('Expected "(", found "{}" on line {}'.format(
+            tokens[index].match,
+            tokens[index].line,
+        ))
+
+    if tokens[index].type == 'close_parenthese':
+        index += 1
+    else:
+        raise Exception('Expected ")", found "{}" on line {}'.format(
+            tokens[index].match,
+            tokens[index].line,
+        ))
+
+    if tokens[index].type == 'symbol' and tokens[index].match == 'do':
+        index += 1
+    else:
+        return failure
+
+    success, index, statement_list = _zero_or_more_parser(tuple, _statement_parser)(index, tokens)
+
+    _, index, _ = consume_newlines(index, tokens)
+
+    if tokens[index].type == 'keyword' and tokens[index].match == 'end':
+        index += 1
+    else:
+        return failure
+
+    return True, index, FurFunctionDefinitionStatement(name=name, statement_list=statement_list)
+
 def _statement_parser(index, tokens):
     _, index, _ = consume_newlines(index, tokens)
 
@@ -320,7 +395,8 @@ def _statement_parser(index, tokens):
 
     return _or_parser(
         _assignment_statement_parser,
-        _expression_parser,
+        _expression_statement_parser,
+        _function_definition_statement_parser,
     )(index, tokens)
 
 def _program_formatter(statement_list):