Merge pull request #1356 from lark-parser/standalone_interactive

Standalone: Added support for interactive parser.

Author: erezsh

lark/parsers/lalr_interactive_parser.py

@@ -7,6 +7,7 @@
 from lark.exceptions import UnexpectedToken
 from lark.lexer import Token, LexerThread
 
+###{standalone
 
 class InteractiveParser:
     """InteractiveParser gives you advanced control over parsing and error handling when parsing with LALR.
@@ -152,3 +153,5 @@ def as_mutable(self):
         """Convert to an ``InteractiveParser``."""
         p = copy(self)
         return InteractiveParser(p.parser, p.parser_state, p.lexer_thread)
+
+###}

lark/tools/standalone.py

@@ -24,6 +24,7 @@
 #
 #
 
+from copy import deepcopy
 from abc import ABC, abstractmethod
 from types import ModuleType
 from typing import (
@@ -65,6 +66,7 @@
     'parsers/lalr_analysis.py',
     'parsers/lalr_parser_state.py',
     'parsers/lalr_parser.py',
+    'parsers/lalr_interactive_parser.py',
     'parser_frontends.py',
     'lark.py',
     'indenter.py',

tests/test_parser.py

@@ -2542,7 +2542,7 @@ def test_parser_interactive_parser(self):
 
             res = ip.feed_eof(ip.lexer_thread.state.last_token)
             self.assertEqual(res, Tree('start', ['a', 'b']))
-            self.assertRaises(UnexpectedToken ,ip.feed_eof)
+            self.assertRaises(UnexpectedToken, ip.feed_eof)
 
             self.assertRaises(UnexpectedToken, ip_copy.feed_token, Token('A', 'a'))
             ip_copy.feed_token(Token('B', 'b'))

tests/test_tools.py

@@ -51,6 +51,46 @@ def test_simple(self):
         l = _Lark()
         x = l.parse('12 elephants')
 
+    def test_interactive(self):
+        grammar = """
+                start: A+ B*
+                A: "a"
+                B: "b"
+        """
+        context = self._create_standalone(grammar)
+        parser: Lark = context['Lark_StandAlone']()
+
+        ip = parser.parse_interactive()
+
+        UnexpectedToken = context['UnexpectedToken']
+        Token = context['Token']
+
+        self.assertRaises(UnexpectedToken, ip.feed_eof)
+        self.assertRaises(TypeError, ip.exhaust_lexer)
+        ip.feed_token(Token('A', 'a'))
+        res = ip.feed_eof()
+        self.assertEqual(res, Tree('start', ['a']))
+
+        ip = parser.parse_interactive("ab")
+
+        ip.exhaust_lexer()
+
+        ip_copy = ip.copy()
+        self.assertEqual(ip_copy.parser_state, ip.parser_state)
+        self.assertEqual(ip_copy.lexer_thread.state, ip.lexer_thread.state)
+        self.assertIsNot(ip_copy.parser_state, ip.parser_state)
+        self.assertIsNot(ip_copy.lexer_thread.state, ip.lexer_thread.state)
+        self.assertIsNot(ip_copy.lexer_thread.state.line_ctr, ip.lexer_thread.state.line_ctr)
+
+        res = ip.feed_eof(ip.lexer_thread.state.last_token)
+        self.assertEqual(res, Tree('start', ['a', 'b']))
+        self.assertRaises(UnexpectedToken, ip.feed_eof)
+
+        self.assertRaises(UnexpectedToken, ip_copy.feed_token, Token('A', 'a'))
+        ip_copy.feed_token(Token('B', 'b'))
+        res = ip_copy.feed_eof()
+        self.assertEqual(res, Tree('start', ['a', 'b', 'b']))
+
     def test_contextual(self):
         grammar = """
         start: a b