From fe0547445967f3ca3543da915fcb38d403b707a1 Mon Sep 17 00:00:00 2001
From: David Halter <davidhalter88@gmail.com>
Date: Fri, 14 Dec 2012 12:19:07 +0100
Subject: [PATCH] added a first version of fast_parser

---
 jedi/fast_parser.py | 138 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 138 insertions(+)
 create mode 100644 jedi/fast_parser.py

diff --git a/jedi/fast_parser.py b/jedi/fast_parser.py
new file mode 100644
index 00000000..f4f09431
--- /dev/null
+++ b/jedi/fast_parser.py
@@ -0,0 +1,138 @@
+import re
+import operator
+from functools import reduce
+
+import parsing
+from _compatibility import use_metaclass
+
+parser_cache = {}
+
+
+class Module(parsing.Simple, parsing.Module):
+    def __init__(self, parsers):
+        super(Module, self).__init__((0,0))
+        self.parsers = parsers
+        self.reset_caches()
+
+        self.subscopes = []
+        self.imports = []
+        self.statements = []
+        self.asserts = []
+
+    def reset_caches(self):
+        """ This module does a whole lot of caching, because it uses different
+        parsers. """
+        self.cache = {}
+        self.modules = [p.module for p in self.parsers]
+
+    def _get(self, name, operation, *args, **kwargs):
+        key = (name, args, frozenset(kwargs.items()))
+        if key not in self.cache:
+            objs = (getattr(m, name)(*args, **kwargs) for m in self.modules)
+            self.cache[key] = reduce(operation, objs)
+        return self.cache[key]
+
+    def __getattr__(self, name):
+        operators = {'get_imports': operator.add,
+                     'get_code': operator.add,
+                     'get_set_vars': operator.add,
+                     'get_defined_names': operator.add,
+                     'is_empty': operator.and_
+                    }
+        properties = {'subscopes': operator.add,
+                      'imports': operator.add,
+                      'statements': operator.add,
+                      'imports': operator.add,
+                      'asserts': operator.add
+                     }
+        if name in operators:
+            return lambda *args, **kwargs: self._get(name, operators[name],
+                                                        *args, **kwargs)
+        elif name in properties:
+            return self._get(name, properties[name])
+
+    def get_statement_for_position(self, pos):
+        key = 'get_statement_for_position', pos
+        if key not in self.cache:
+            for p in self.parsers:
+                s = p.module.get_statement_for_position(self)
+                if s:
+                    self.cache[key] = s
+                    break
+        return self.cache[key]
+
+    @property
+    def docstr(self):
+        return self.modules[0].docstr
+
+    @property
+    def name(self):
+        return self.modules[0].name
+
+    @property
+    def is_builtin(self):
+        return self.modules[0].is_builtin
+
+    def __repr__(self):
+        return "<%s: %s@%s-%s>" % (type(self).__name__, self.name,
+                                    self.start_pos[0], self.end_pos[0])
+
+
+class CachedFastParser(type):
+    """ This is a metaclass for caching `FastParser`. """
+    def __call__(self, code, module_path=None, user_position=None):
+        if module_path is None or module_path not in parser_cache:
+            p = super(CachedFastParser, self).__call__(code, module_path)
+            parser_cache[module_path] = p
+        else:
+            p = parser_cache[module_path]
+            p.update(code, user_position)
+        return p
+
+
+class FastParser(use_metaclass(CachedFastParser)):
+    def __init__(self, code, module_path=None, user_position=None):
+        # set values like `parsing.Module`.
+        self.module_path = module_path
+        self.user_position = user_position
+
+        self.parsers = []
+        self.module = Module(self.parsers)
+        self._parse(code)
+
+        self.reset_caches()
+
+    @property
+    def user_scope(self):
+        if self._user_scope is None:
+            for p in self.parsers:
+                if p.user_scope:
+                    self._user_scope = p.user_scope
+        return self._user_scope
+
+    @property
+    def user_stmt(self):
+        if self._user_stmt is None:
+            for p in self.parsers:
+                if p.user_stmt:
+                    self._user_stmt = p.user_stmt
+        return self._user_stmt
+
+    def update(self, code, user_position=None):
+        self.user_position = user_position
+        self._parse(code)
+        self.reset_caches()
+
+    def _parse(self, code):
+        parts = re.split(r'\n(?:def|class).*?(?!\n(?:def|class))')
+        line_offset = 0
+        for p in parts:
+            lines = p.count('\n')
+            p = parsing.PyFuzzyParser(p, self.module_path, self.user_position,
+                                line_offset=line_offset, stop_on_scope=True)
+            line_offset += lines
+            self.parsers.append(p)
+
+    def reset_caches(self):
+        self._user_scope = None
+        self.module.reset_caches()