Merge branch 'fix-818' of https://github.com/MegaIng/lark into MegaIng-fix-818

lark/lark.py

@@ -343,9 +343,7 @@ class Lark(Serialize):
                     rule.options.priority = None
 
         # TODO Deprecate lexer_callbacks?
-        lexer_callbacks = (_get_lexer_callbacks(self.options.transformer, self.terminals)
-                           if self.options.transformer
-                           else {})
+        lexer_callbacks = {}
         lexer_callbacks.update(self.options.lexer_callbacks)
 
         self.lexer_conf = LexerConf(self.terminals, re_module, self.ignore_tokens, self.options.postlex, lexer_callbacks, self.options.g_regex_flags, use_bytes=self.options.use_bytes)
@@ -375,8 +373,7 @@ class Lark(Serialize):
         return TraditionalLexer(lexer_conf)
 
     def _prepare_callbacks(self):
-        self.parser_class = get_frontend(self.options.parser, self.options.lexer)
-        self._callbacks = None
+        self._callbacks = {}
         # we don't need these callbacks if we aren't building a tree
         if self.options.ambiguity != 'forest':
             self._parse_tree_builder = ParseTreeBuilder(
@@ -386,9 +383,11 @@ class Lark(Serialize):
                     self.options.parser != 'lalr' and self.options.ambiguity == 'explicit',
                     self.options.maybe_placeholders
                 )
-            self._callbacks = self._parse_tree_builder.create_callback(self.options.transformer)
+            self._callbacks.update(self._parse_tree_builder.create_callback(self.options.transformer))
+        self._callbacks.update(_get_lexer_callbacks(self.options.transformer, self.terminals))
 
     def _build_parser(self):
+        self.parser_class = get_frontend(self.options.parser, self.options.lexer)
         self._prepare_callbacks()
         parser_conf = ParserConf(self.rules, self._callbacks, self.options.start)
         return self.parser_class(self.lexer_conf, parser_conf, options=self.options)
@@ -428,16 +427,21 @@ class Lark(Serialize):
         self.options = LarkOptions.deserialize(options, memo)
         self.rules = [Rule.deserialize(r, memo) for r in data['rules']]
         self.source_path = '<deserialized>'
+        self.parser_class = get_frontend(self.options.parser, self.options.lexer)
+        self.lexer_conf = self.parser_class.deserialize_lexer_conf( # We need the terminals list to for _prepare_callbacks
+            data['parser'], 
+            memo, 
+            self.options)
+        self.terminals = self.lexer_conf.terminals
+        self._terminals_dict = {t.name: t for t in self.terminals}
         self._prepare_callbacks()
         self.parser = self.parser_class.deserialize(
             data['parser'],
             memo,
+            self.lexer_conf,
             self._callbacks,
             self.options,  # Not all, but multiple attributes are used
         )
-        self.lexer_conf = self.parser.lexer_conf
-        self.terminals = self.parser.lexer_conf.terminals
-        self._terminals_dict = {t.name: t for t in self.terminals}
         return self
 
     @classmethod

lark/parser_frontends.py

@@ -38,23 +38,26 @@ class MakeParsingFrontend:
         parser_conf.parser_type = self.parser_type
         lexer_conf.lexer_type = self.lexer_type
         return ParsingFrontend(lexer_conf, parser_conf, options)
-
+    
     @classmethod
-    def deserialize(cls, data, memo, callbacks, options):
-        lexer_conf = LexerConf.deserialize(data['lexer_conf'], memo)
-        parser_conf = ParserConf.deserialize(data['parser_conf'], memo)
-        parser = LALR_Parser.deserialize(data['parser'], memo, callbacks, options.debug)
-        parser_conf.callbacks = callbacks
-
+    def deserialize_lexer_conf(cls, data, memo, options):
+        # We need lexer_conf earley to have the terminals that we need to produce the callback list for paser_conf
+        # So we split deserialize into two methods
         terminals = [item for item in memo.values() if isinstance(item, TerminalDef)]
-
+        lexer_conf = LexerConf.deserialize(data['lexer_conf'], memo)
         lexer_conf.callbacks = _get_lexer_callbacks(options.transformer, terminals)
         lexer_conf.re_module = regex if options.regex else re
         lexer_conf.use_bytes = options.use_bytes
         lexer_conf.g_regex_flags = options.g_regex_flags
         lexer_conf.skip_validation = True
         lexer_conf.postlex = options.postlex
+        return lexer_conf
 
+    @classmethod
+    def deserialize(cls, data, memo, lexer_conf, callbacks, options):
+        parser_conf = ParserConf.deserialize(data['parser_conf'], memo)
+        parser = LALR_Parser.deserialize(data['parser'], memo, callbacks, options.debug)
+        parser_conf.callbacks = callbacks
         return ParsingFrontend(lexer_conf, parser_conf, options, parser=parser)
 
 

lark/parsers/lalr_parser.py

@@ -129,7 +129,7 @@ class ParserState(object):
                 # shift once and return
                 assert not is_end
                 state_stack.append(arg)
-                value_stack.append(token)
+                value_stack.append(token if token.type not in callbacks else callbacks[token.type](token))
                 return
             else:
                 # reduce+shift as many times as necessary

tests/test_parser.py

@@ -10,7 +10,7 @@ from copy import copy, deepcopy
 
 from lark.utils import Py36, isascii
 
-from lark import Token
+from lark import Token, Transformer_NonRecursive
 
 try:
     from cStringIO import StringIO as cStringIO
@@ -34,7 +34,7 @@ from lark import logger
 from lark.lark import Lark
 from lark.exceptions import GrammarError, ParseError, UnexpectedToken, UnexpectedInput, UnexpectedCharacters
 from lark.tree import Tree
-from lark.visitors import Transformer, Transformer_InPlace, v_args
+from lark.visitors import Transformer, Transformer_InPlace, v_args, Transformer_InPlaceRecursive
 from lark.grammar import Rule
 from lark.lexer import TerminalDef, Lexer, TraditionalLexer
 from lark.indenter import Indenter
@@ -162,6 +162,28 @@ class TestParsers(unittest.TestCase):
         r = p.parse("x")
         self.assertEqual( r.children, ["X!"] )
 
+    def test_visit_tokens2(self):
+        g = """
+        start: add+
+        add: NUM "+" NUM
+        NUM: /\d+/
+        %ignore " "
+        """
+        text = "1+2 3+4"
+        expected = Tree('start', [3, 7])
+        for base in (Transformer, Transformer_InPlace, Transformer_NonRecursive, Transformer_InPlaceRecursive):
+            class T(base):
+                def add(self, children):
+                    return sum(children if isinstance(children, list) else children.children)
+                
+                def NUM(self, token):
+                    return int(token)
+                
+            
+            parser = Lark(g, parser='lalr', transformer=T())
+            result = parser.parse(text)
+            self.assertEqual(result, expected)
+
     def test_vargs_meta(self):
 
         @v_args(meta=True)