X-Git-Url: https://code.kerkeslager.com/?p=fur;a=blobdiff_plain;f=parsing.py;h=b2a14a888b820346c0f0086beb52e4b58c38e4a0;hp=7240b5243e40ffd7655b4dc5bc4fbb94fbe65f5a;hb=3da330f045ed7fcb66ee9d9447de320680263699;hpb=74c7456042282dd86f9be673cbd1e00496b28710

diff --git a/parsing.py b/parsing.py
index 7240b52..b2a14a8 100644
--- a/parsing.py
+++ b/parsing.py
@@ -39,21 +39,21 @@ def _zero_or_more_parser(formatter, parser):
 FurIntegerLiteralExpression = collections.namedtuple(
     'FurIntegerLiteralExpression',
     [
-        'value',
+        'integer',
     ],
 )
 
 FurStringLiteralExpression = collections.namedtuple(
     'FurStringLiteralExpression',
     [
-        'value',
+        'string',
     ],
 )
 
 FurSymbolExpression = collections.namedtuple(
     'FurSymbolExpression',
     [
-        'value',
+        'symbol',
     ],
 )
 
@@ -82,41 +82,47 @@ def _integer_literal_expression_parser(index, tokens):
     value = int(tokens[index].match)
     index += 1
 
-    return True, index, FurIntegerLiteralExpression(value=value)
+    return True, index, FurIntegerLiteralExpression(integer=value)
 
 def _string_literal_expression_parser(index, tokens):
     if tokens[index].type == 'single_quoted_string_literal':
-        return (True, index + 1, FurStringLiteralExpression(value=tokens[index].match[1:-1]))
+        return (True, index + 1, FurStringLiteralExpression(string=tokens[index].match[1:-1]))
 
     return (False, index, None)
 
 def _symbol_expression_parser(index, tokens):
     if tokens[index].type == 'symbol':
-        return (True, index + 1, FurSymbolExpression(value=tokens[index].match))
+        return (True, index + 1, FurSymbolExpression(symbol=tokens[index].match))
 
     return (False, index, None)
 
-def _parenthesized_expression_parser(index, tokens):
-    failure = (False, index, None)
+def _parenthese_wrapped_parser(internal_parser):
+    def result_parser(index, tokens):
+        failure = (False, index, None)
 
-    if tokens[index].type == 'open_parenthese':
-        index += 1
-    else:
-        return failure
+        if tokens[index].type == 'open_parenthese':
+            index += 1
+        else:
+            return failure
 
-    success, index, internal = _expression_parser(index, tokens)
-    if not success:
-        return failure
+        success, index, internal = internal_parser(index, tokens)
+        if not success:
+            return failure
 
-    if tokens[index].type == 'close_parenthese':
-        index += 1
-    else:
-        raise Exception('Expected ")" on line {}, found "{}"'.format(
-            tokens[index].line,
-            tokens[index].match,
-        ))
+        if tokens[index].type == 'close_parenthese':
+            index += 1
+        else:
+            raise Exception('Expected ")" on line {}, found "{}"'.format(
+                tokens[index].line,
+                tokens[index].match,
+            ))
+
+        return True, index, internal
 
-    return True, index, internal
+    return result_parser
+
+def _parenthesized_expression_parser(index, tokens):
+    return _parenthese_wrapped_parser(_expression_parser)(index, tokens)
 
 def _negation_expression_parser(index, tokens):
     failure = (False, index, None)
@@ -274,8 +280,6 @@ FurProgram = collections.namedtuple(
 )
 
 def _function_call_expression_parser(index, tokens):
-    # TODO Allow function calls as the source of the function. This requires a
-    # left-recursive parser, however.
     failure = (False, index, None)
 
     # We have to be careful what expressions we add here. Otherwise expressions
@@ -288,23 +292,28 @@ def _function_call_expression_parser(index, tokens):
     if not success:
         return failure
 
-    if tokens[index].type != 'open_parenthese':
-        return failure
-    index += 1
-
-    success, index, arguments = _comma_separated_expression_list_parser(index, tokens)
+    success, index, arguments = _parenthese_wrapped_parser(_comma_separated_expression_list_parser)(
+        index,
+        tokens,
+    )
 
     if not success:
         return failure
 
-    if tokens[index].type != 'close_parenthese':
-        raise Exception('Expected ")", found "{}" on line {}'.format(
-            tokens[index].match,
-            tokens[index].line,
-        ))
-    index += 1
+    while success and index < len(tokens):
+        # "function" is actually the full function call if the next parse attempt doesn't succeed
+        # We can't give this a better name without a bunch of checks, however.
+        function = FurFunctionCallExpression(
+            function=function,
+            arguments=arguments,
+        )
+
+        success, index, arguments = _parenthese_wrapped_parser(_comma_separated_expression_list_parser)(
+            index,
+            tokens,
+        )
 
-    return True, index, FurFunctionCallExpression(function=function, arguments=arguments)
+    return True, index, function
 
 _expression_parser = _or_level_expression_parser
 
@@ -318,18 +327,28 @@ def _expression_statement_parser(index, tokens):
 
     return (True, index, FurExpressionStatement(expression=expression))
 
+BUILTINS = {'print', 'pow'}
+
 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)
 
-    if tokens[index].type != 'symbol':
+    if tokens[index].type == 'symbol':
+        target = tokens[index].match
+        target_assignment_line = tokens[index].line
+
+        index += 1
+    else:
         return failure
-    target = tokens[index].match
-    index += 1
 
-    if tokens[index].type != 'assignment_operator':
+
+    if tokens[index].type == 'assignment_operator':
+        if target in BUILTINS:
+            raise Exception(
+                'Trying to assign to builtin "{}" on line {}'.format(target, target_assignment_line),
+            )
+        assignment_operator_index = index
+    else:
         return failure
-    assignment_operator_index = index
 
     success, index, expression = _expression_parser(index + 1, tokens)
 
@@ -396,7 +415,7 @@ def _function_definition_statement_parser(index, tokens):
 
     return True, index, FurFunctionDefinitionStatement(
         name=name,
-        argument_name_list=tuple(an.value for an in argument_name_list),
+    argument_name_list=tuple(an.symbol for an in argument_name_list),
         statement_list=statement_list,
     )
 
@@ -443,7 +462,7 @@ if __name__ == '__main__':
                 (
                     True,
                     1,
-                    FurStringLiteralExpression(value='Hello, world'),
+                    FurStringLiteralExpression(string='Hello, world'),
                 ),
             )
 
@@ -456,7 +475,7 @@ if __name__ == '__main__':
                     4,
                     FurFunctionCallExpression(
                         name='print',
-                        arguments=(FurStringLiteralExpression(value='Hello, world'),),
+                        arguments=(FurStringLiteralExpression(string='Hello, world'),),
                     ),
                 ),
             )