Working on #48 : Added BaseExprParser and BaseNodeParser.py

src/core/sheerka/services/SheerkaExecute.py

@@ -42,7 +42,7 @@ class ParserInput:
         self.yield_oef = yield_oef
 
         self.start = start or 0
-        if end:
+        if end is not None:
             self.original_end = end  # forced index of the last token
             self.end = self.original_end  # index of the last token => len(tokens) - 1 if full tokens
         else:
@@ -115,6 +115,7 @@ class ParserInput:
         self.pos += 1
 
         if self.pos > self.end:
+            self.token = self.tokens[-1]
             return False
 
         self.token = self.tokens[self.pos]
@@ -128,7 +129,11 @@ class ParserInput:
                     return False
                 self.token = self.tokens[self.pos]
 
-        return self.pos <= self.end
+        if self.pos <= self.end:
+            return True
+        else:
+            self.token = self.tokens[-1]
+            return False
 
     def the_token_after(self, skip_whitespace=True):
         """
@@ -137,13 +142,13 @@ class ParserInput:
         """
         my_pos = self.pos + 1
         if my_pos > self.end:
-            return Token(TokenKind.EOF, "", -1, -1, -1)
+            return self.tokens[-1]
 
         if skip_whitespace:
             while self.tokens[my_pos].type in (TokenKind.WHITESPACE, TokenKind.NEWLINE):
                 my_pos += 1
                 if my_pos > self.end:
-                    return Token(TokenKind.EOF, "", -1, -1, -1)
+                    return self.tokens[-1]
 
         return self.tokens[my_pos]
 

src/parsers/BaseCustomGrammarParser.py

@@ -2,7 +2,8 @@ from dataclasses import dataclass, field
 
 import core.utils
 from core.tokenizer import Keywords, TokenKind, Tokenizer
-from parsers.BaseParser import BaseParser, Node, ParsingError, UnexpectedEofParsingError, UnexpectedTokenParsingError
+from parsers.BaseParser import Node, ParsingError, UnexpectedEofParsingError, UnexpectedTokenParsingError, \
+    BaseParserInputParser
 
 
 @dataclass()
@@ -94,7 +95,7 @@ class NameNode(CustomGrammarParserNode):
         return hash(self.get_name())
 
 
-class BaseCustomGrammarParser(BaseParser):
+class BaseCustomGrammarParser(BaseParserInputParser):
     """
     Base class for sheerka specific grammars
     """

src/parsers/BaseNodeParser.py

@@ -4,7 +4,7 @@ from enum import Enum
 import core.utils
 from core.tokenizer import TokenKind, Token
 from core.var_ref import VariableRef
-from parsers.BaseParser import Node, BaseParser, ParsingError
+from parsers.BaseParser import Node, ParsingError, BaseParserInputParser
 
 DEBUG_COMPILED = True
 
@@ -461,7 +461,7 @@ class SyaAssociativity(Enum):
         return self.value
 
 
-class BaseNodeParser(BaseParser):
+class BaseNodeParser(BaseParserInputParser):
     """
     Parser that return LexerNode
     """

src/parsers/BaseParser.py

@@ -62,11 +62,6 @@ class BaseParser:
         self.short_name = name
         self.priority = priority
         self.enabled = enabled
-
-        self.error_sink = []
-        self.context: ExecutionContext = None
-        self.sheerka = None
-        self.parser_input: ParserInput = None
         self.yield_eof = yield_eof
 
     def __eq__(self, other):
@@ -80,6 +75,74 @@ class BaseParser:
     def __repr__(self):
         return self.name
 
+    def log_result(self, context, source, ret):
+        pass
+        # if not self.log.isEnabledFor(logging.DEBUG):
+        #     return
+        #
+        # if ret.status:
+        #     value = context.return_value_to_str(ret)
+        #     context.log(f"Recognized '{source}' as {value}", self.name)
+        # else:
+        #     context.log(f"Failed to recognize '{source}'", self.name)
+
+    def log_multiple_results(self, context, source, list_of_ret):
+        pass
+        # if not self.log.isEnabledFor(logging.DEBUG):
+        #     return
+        #
+        # context.log(f"Recognized '{source}' as multiple concepts", self.name)
+        # for r in list_of_ret:
+        #     value = context.return_value_to_str(r)
+        #     context.log(f"  Recognized '{value}'", self.name)
+
+    def get_return_value_body(self, sheerka, source, parsed, try_parse, errors):
+        """
+        All parsers must return their result in a standard way
+        :param sheerka:
+        :param source:
+        :param parsed:
+        :param try_parse:
+        :param errors:
+        :return:
+        """
+        if len(errors) == 1 and isinstance(errors[0], Concept):
+            return errors[0]
+
+        if len(errors):
+            if parsed is None:
+                return sheerka.new(BuiltinConcepts.NOT_FOR_ME,
+                                   body=source,
+                                   reason=errors)
+            else:
+                return sheerka.new(BuiltinConcepts.ERROR,
+                                   body=errors)
+
+        return sheerka.new(BuiltinConcepts.PARSER_RESULT,
+                           parser=self,
+                           source=source,
+                           body=parsed,
+                           try_parsed=try_parse)
+
+    @staticmethod
+    def get_name(name):
+        return BaseParser.PREFIX + name
+
+
+class BaseParserInputParser(BaseParser):
+    """
+    Base parser for stateful parser where context, parser input, and error sink are part of the class
+    """
+
+    def __init__(self, name, priority: int, enabled=True, yield_eof=False):
+        super(BaseParserInputParser, self).__init__(name, priority, enabled, yield_eof)
+
+        self.error_sink = []
+        self.context: ExecutionContext = None
+        self.sheerka = None
+        self.parser_input: ParserInput = None
+        self.yield_eof = yield_eof
+
     def reset_parser(self, context, parser_input: ParserInput):
         self.context = context
         self.sheerka = context.sheerka
@@ -106,54 +169,6 @@ class BaseParser:
     def has_error(self):
         return len(self.error_sink) > 0
 
-    def log_result(self, context, source, ret):
-        pass
-        # if not self.log.isEnabledFor(logging.DEBUG):
-        #     return
-        #
-        # if ret.status:
-        #     value = context.return_value_to_str(ret)
-        #     context.log(f"Recognized '{source}' as {value}", self.name)
-        # else:
-        #     context.log(f"Failed to recognize '{source}'", self.name)
-
-    def log_multiple_results(self, context, source, list_of_ret):
-        pass
-        # if not self.log.isEnabledFor(logging.DEBUG):
-        #     return
-        #
-        # context.log(f"Recognized '{source}' as multiple concepts", self.name)
-        # for r in list_of_ret:
-        #     value = context.return_value_to_str(r)
-        #     context.log(f"  Recognized '{value}'", self.name)
-
-    def get_return_value_body(self, sheerka, source, parsed, try_parse):
-        """
-        All parsers must return their result in a standard way
-        :param sheerka:
-        :param source:
-        :param parsed:
-        :param try_parse:
-        :return:
-        """
-        if len(self.error_sink) == 1 and isinstance(self.error_sink[0], Concept):
-            return self.error_sink[0]
-
-        if self.has_error:
-            if parsed is None:
-                return sheerka.new(BuiltinConcepts.NOT_FOR_ME,
-                                   body=source,
-                                   reason=self.error_sink)
-            else:
-                return sheerka.new(BuiltinConcepts.ERROR,
-                                   body=self.error_sink)
-
-        return sheerka.new(BuiltinConcepts.PARSER_RESULT,
-                           parser=self,
-                           source=source,
-                           body=parsed,
-                           try_parsed=try_parse)
-
     @staticmethod
     def get_input_as_lexer_nodes(parser_input, expected_parser=None):
         """
@@ -229,12 +244,34 @@ class BaseParser:
 
         return list_a
 
-    @staticmethod
-    def get_name(name):
-        return BaseParser.PREFIX + name
-
 
 class BaseExprParser(BaseParser):
 
-    def parse_input(self):
+    def parse_input(self, context, parser_input, error_sink):
         raise NotImplementedError
+
+    def reset_parser_input(self, parser_input: ParserInput, error_sink):
+        try:
+            error_sink.clear()
+            parser_input.reset(self.yield_eof)
+        except LexerError as e:
+            error_sink.add_error(e)
+            return False
+
+        parser_input.next_token()
+        return True
+
+
+class ErrorSink:
+    def __init__(self):
+        self.sink = []
+
+    def add_error(self, error):
+        self.sink.append(error)
+
+    def clear(self):
+        self.sink.clear()
+
+    @property
+    def has_error(self):
+        return len(self.sink) > 0

src/parsers/BnfDefinitionParser.py

@@ -33,6 +33,7 @@ class BnfDefinitionParser(BaseParser):
         self.context = None
         self.source = ""
         self.sheerka = None
+        self.error_sink = []
 
     def __eq__(self, other):
         if not isinstance(other, BnfDefinitionParser):
@@ -60,6 +61,10 @@ class BnfDefinitionParser(BaseParser):
             self.next_token()
         return error
 
+    @property
+    def has_error(self):
+        return len(self.error_sink) > 0
+
     def get_token(self) -> Token:
         return self._current
 
@@ -123,7 +128,7 @@ class BnfDefinitionParser(BaseParser):
                 False,
                 context.sheerka.new(BuiltinConcepts.ERROR, body=[e]))
 
-        value = self.get_return_value_body(context.sheerka, self.source, tree, tree)
+        value = self.get_return_value_body(context.sheerka, self.source, tree, tree, self.error_sink)
 
         ret = self.sheerka.ret(
             self.name,

src/parsers/DefConceptParser.py

@@ -85,7 +85,7 @@ class DefConceptParser(BaseCustomGrammarParser):
         self.parser_input.next_token()
         node = self.parse_def_concept()
 
-        body = self.get_return_value_body(sheerka, parser_input.as_text(), node, node)
+        body = self.get_return_value_body(sheerka, parser_input.as_text(), node, node, self.error_sink)
         ret = sheerka.ret(self.name, not self.has_error, body)
 
         self.log_result(context, parser_input.as_text(), ret)

src/parsers/DefRuleParser.py

@@ -71,7 +71,7 @@ class DefRuleParser(BaseCustomGrammarParser):
         self.parser_input.next_token()
         node = self.parse_def_rule()
 
-        body = self.get_return_value_body(sheerka, parser_input.as_text(), node, node)
+        body = self.get_return_value_body(sheerka, parser_input.as_text(), node, node, self.error_sink)
         ret = sheerka.ret(self.name, not self.has_error, body)
 
         self.log_result(context, parser_input.as_text(), ret)

src/parsers/ExactConceptParser.py

@@ -4,10 +4,10 @@ from core.concept import VARIABLE_PREFIX
 from core.sheerka.services.SheerkaExecute import ParserInput
 from core.tokenizer import TokenKind
 from core.utils import str_concept
-from parsers.BaseParser import BaseParser
+from parsers.BaseParser import BaseParser, BaseParserInputParser
 
 
-class ExactConceptParser(BaseParser):
+class ExactConceptParser(BaseParserInputParser):
     """
     Tries to recognize a single concept
     """
@@ -15,7 +15,7 @@ class ExactConceptParser(BaseParser):
     MAX_WORDS_SIZE = 6
 
     def __init__(self, max_word_size=None, **kwargs):
-        BaseParser.__init__(self, "ExactConcept", 80)
+        BaseParserInputParser.__init__(self, "ExactConcept", 80)
         self.max_word_size = max_word_size
 
     def parse(self, context, parser_input: ParserInput):

src/parsers/ExpressionParser.py

@@ -2,7 +2,7 @@ from core.builtin_concepts_ids import BuiltinConcepts
 from core.sheerka.services.SheerkaExecute import ParserInput
 from core.tokenizer import TokenKind
 from core.utils import get_text_from_tokens
-from parsers.BaseParser import BaseExprParser
+from parsers.BaseParser import BaseExprParser, ErrorSink
 from parsers.FunctionParser import FunctionParser
 from parsers.LogicalOperatorParser import LogicalOperatorParser
 from parsers.RelationalOperatorParser import RelationalOperatorParser
@@ -18,9 +18,10 @@ class ExpressionParser(BaseExprParser):
 
     def __init__(self, **kwargs):
         super().__init__(ExpressionParser.NAME, 60, False, yield_eof=False)
-        self.logical_parser = LogicalOperatorParser()
+        self.variable_parser = VariableOrNamesParser()
-        self.relational_parser = RelationalOperatorParser()
         self.function_parser = FunctionParser()
+        self.relational_parser = RelationalOperatorParser()
+        self.logical_parser = LogicalOperatorParser(expr_parser=self.variable_parser)
 
     def parse(self, context, parser_input: ParserInput):
         """
@@ -40,61 +41,109 @@ class ExpressionParser(BaseExprParser):
                                        False,
                                        sheerka.new(BuiltinConcepts.IS_EMPTY))
 
-        if not self.reset_parser(context, parser_input):
+        error_sink = ErrorSink()
-            return self.sheerka.ret(
+        if not self.reset_parser_input(parser_input, error_sink):
+            return context.sheerka.ret(
                 self.name,
                 False,
-                context.sheerka.new(BuiltinConcepts.ERROR, body=self.error_sink))
+                context.sheerka.new(BuiltinConcepts.ERROR, body=error_sink.sink))
 
-        self.parser_input.next_token()
+        node = self.parse_input(context, parser_input, error_sink)
-
-        node = self.parse_input()
         if isinstance(node, ParenthesisNode):
             node = node.node
 
-        value = self.get_return_value_body(context.sheerka, self.parser_input.as_text(), node, node)
+        value = self.get_return_value_body(context.sheerka, parser_input.as_text(), node, node, error_sink.sink)
 
-        ret = self.sheerka.ret(
+        ret = context.sheerka.ret(
             self.name,
-            not self.has_error,
+            not error_sink.has_error,
             value)
 
         return ret
 
-    def parse_input(self):
+    def parse_input(self, context, parser_input, error_sink):
-        pos = self.parser_input.pos
+        pos = parser_input.pos
-        for parser in []:  # [self.logical_parser, self.relational_parser, self.function_parser]:
+        for parser in [self.logical_parser,
-            self.parser_input.seek(pos)  # reset position
+                       self.variable_parser]:  # [self.logical_parser, self.relational_parser, self.function_parser]:
-            if parser.reset_parser(self.context, self.parser_input):
+            parser_input.seek(pos)  # reset position
-                res = parser.parse_input()
+            res = parser.parse_input(context, parser_input, error_sink)
-                if res and not parser.has_error:
+            if res and not error_sink.has_error:
-                    return res
+                return res
 
+        return None
+
+
+class VariableOrNamesParser(BaseExprParser):
+    NAME = "VariableOrNames"
+
+    def __init__(self, **kwargs):
+        super().__init__(VariableOrNamesParser.NAME, 60, False, yield_eof=False)
+
+    def parse(self, context, parser_input: ParserInput):
+        """
+        :param context:
+        :param parser_input:
+        :return:
+        """
+
+        if not isinstance(parser_input, ParserInput):
+            return None
+
+        context.log(f"Parsing '{parser_input}' with {self.NAME}Parser", self.name)
+        sheerka = context.sheerka
+
+        if parser_input.is_empty():
+            return context.sheerka.ret(self.name,
+                                       False,
+                                       sheerka.new(BuiltinConcepts.IS_EMPTY))
+
+        error_sink = ErrorSink()
+        if not self.reset_parser_input(parser_input, error_sink):
+            return context.sheerka.ret(
+                self.name,
+                False,
+                context.sheerka.new(BuiltinConcepts.ERROR, body=error_sink.sink))
+
+        node = self.parse_input(context, parser_input, error_sink)
+        if isinstance(node, ParenthesisNode):
+            node = node.node
+
+        value = self.get_return_value_body(context.sheerka, parser_input.as_text(), node, node, error_sink.sink)
+
+        ret = context.sheerka.ret(
+            self.name,
+            not error_sink.has_error,
+            value)
+
+        return ret
+
+    def parse_input(self, context, parser_input, error_sink):
         # try to recognize a VariableNode
         dots_found = []
-        for i, token in enumerate(self.parser_input.as_tokens()):
+        pos = parser_input.pos
+        for i, token in enumerate(parser_input.as_tokens()):
             if token.type == TokenKind.DOT:
                 dots_found.append(i)
                 continue
 
             if not (token.type == TokenKind.WHITESPACE or
                     token.type == TokenKind.IDENTIFIER and token.value.isidentifier()):
-                return NameExprNode(self.parser_input.start, self.parser_input.end, self.parser_input.as_tokens())
+                return NameExprNode(parser_input.start, parser_input.end, parser_input.as_tokens())
 
         if len(dots_found) == 0:
-            return VariableNode(pos, self.parser_input.end, self.parser_input.as_tokens(), self.parser_input.as_text())
+            return VariableNode(pos, parser_input.end, parser_input.as_tokens(), parser_input.as_text())
 
         parts = []
         current_dot_pos = pos
         for dot_found in dots_found:
-            parts.append(get_text_from_tokens(self.parser_input.tokens[current_dot_pos: dot_found]))
+            parts.append(get_text_from_tokens(parser_input.tokens[current_dot_pos: dot_found]))
             current_dot_pos = dot_found + 1
 
         # do not forget the trailing part
-        parts.append(get_text_from_tokens(self.parser_input.tokens[current_dot_pos: self.parser_input.end + 1]))
+        parts.append(get_text_from_tokens(parser_input.tokens[current_dot_pos: parser_input.end + 1]))
 
-        return VariableNode(self.parser_input.start,
+        return VariableNode(parser_input.start,
-                            self.parser_input.end,
+                            parser_input.end,
-                            self.parser_input.as_tokens(),
+                            parser_input.as_tokens(),
                             parts[0],
                             *parts[1:])

src/parsers/FunctionParser.py

@@ -7,7 +7,8 @@ from core.sheerka.services.SheerkaExecute import ParserInput
 from core.tokenizer import TokenKind
 from core.utils import get_n_clones
 from parsers.BaseNodeParser import SourceCodeNode, SourceCodeWithConceptNode
-from parsers.BaseParser import UnexpectedTokenParsingError, UnexpectedEofParsingError, Node, BaseExprParser
+from parsers.BaseParser import UnexpectedTokenParsingError, UnexpectedEofParsingError, Node, BaseExprParser, \
+    BaseParserInputParser
 from parsers.BnfNodeParser import BnfNodeParser
 from parsers.PythonWithConceptsParser import PythonWithConceptsParser
 from parsers.RuleParser import RuleParser
@@ -26,7 +27,7 @@ class FunctionParserNode(Node):
     pass
 
 
-class FunctionParser(BaseExprParser):
+class FunctionParser(BaseParserInputParser):
     """
     The parser will be used to parse func(x, y, z)
     where x, y and z can be source code, concepts or other functions

src/parsers/LogicalOperatorParser.py

@@ -7,7 +7,7 @@ from core.sheerka.services.sheerka_service import FailedToCompileError
 from core.tokenizer import TokenKind, Tokenizer, Keywords
 from core.utils import get_text_from_tokens
 from parsers.BaseNodeParser import UnrecognizedTokensNode
-from parsers.BaseParser import BaseParser, UnexpectedTokenParsingError, UnexpectedEofParsingError, BaseExprParser
+from parsers.BaseParser import UnexpectedTokenParsingError, UnexpectedEofParsingError, BaseExprParser, ErrorSink
 from parsers.PythonWithConceptsParser import PythonWithConceptsParser
 from parsers.expressions import ParenthesisNode, OrNode, AndNode, NotNode, LeftPartNotFoundError, \
     ParenthesisMismatchError, NameExprNode, ExprNode, VariableNode, ComparisonNode
@@ -76,6 +76,7 @@ class LogicalOperatorParser(BaseExprParser):
         self.and_tokens = list(Tokenizer(" and ", yield_eof=False))
         self.and_not_tokens = list(Tokenizer(" and not ", yield_eof=False))
         self.not_tokens = list(Tokenizer("not ", yield_eof=False))
+        self.expr_parser = kwargs.get("expr_parser", None)
 
     @staticmethod
     def clean_parenthesis_nodes(nodes):
@@ -101,144 +102,161 @@ class LogicalOperatorParser(BaseExprParser):
                                        False,
                                        sheerka.new(BuiltinConcepts.IS_EMPTY))
 
-        if not self.reset_parser(context, parser_input):
+        error_sink = ErrorSink()
-            return self.sheerka.ret(
+        if not self.reset_parser_input(parser_input, error_sink):
+            return context.sheerka.ret(
                 self.name,
                 False,
-                context.sheerka.new(BuiltinConcepts.ERROR, body=self.error_sink))
+                context.sheerka.new(BuiltinConcepts.ERROR, body=error_sink.sink))
 
-        self.parser_input.next_token()
+        tree = self.parse_input(context, parser_input, error_sink)
-        tree = self.parse_input()
+
-        token = self.parser_input.token
+        token = parser_input.token
         if token and token.type != TokenKind.EOF:
-            self.add_error(UnexpectedTokenParsingError(f"Unexpected token '{token}'", token, []))
+            error_sink.add_error(UnexpectedTokenParsingError(f"Unexpected token '{token}'", token, []))
 
         if isinstance(tree, ParenthesisNode):
             tree = tree.node
-        value = self.get_return_value_body(context.sheerka, self.parser_input.as_text(), tree, tree)
 
-        ret = self.sheerka.ret(
+        value = self.get_return_value_body(context.sheerka,
-            self.name,
+                                           parser_input.as_text(),
-            not self.has_error,
+                                           tree,
-            value)
+                                           tree,
+                                           error_sink.sink)
+
+        ret = context.sheerka.ret(self.name,
+                                  not error_sink.has_error,
+                                  value)
 
         return ret
 
-    def parse_input(self):
+    def parse_input(self, context, parser_input, error_sink):
-        return self.parse_or()
+        return self.parse_or(context, parser_input, error_sink)
 
-    def parse_or(self):
+    def parse_or(self, context, parser_input, error_sink):
-        start = self.parser_input.pos
+        start = parser_input.pos
-        expr = self.parse_and()
+        expr = self.parse_and(context, parser_input, error_sink)
-        token = self.parser_input.token
+        token = parser_input.token
         if token.type != TokenKind.IDENTIFIER or token.value != "or":
             return expr
 
         parts = [expr]
         while token.type == TokenKind.IDENTIFIER and token.value == "or":
-            self.parser_input.next_token()
+            parser_input.next_token()
-            expr = self.parse_and()
+            expr = self.parse_and(context, parser_input, error_sink)
             if expr is None:
-                self.add_error(UnexpectedEofParsingError("When parsing 'or'"))
+                error_sink.add_error(UnexpectedEofParsingError("When parsing 'or'"))
-                end = self.parser_input.pos
+                end = parser_input.pos
                 self.clean_parenthesis_nodes(parts)
-                return OrNode(start, end, self.parser_input.tokens[start: end + 1], *parts)
+                return OrNode(start, end, parser_input.tokens[start: end + 1], *parts)
             parts.append(expr)
-            token = self.parser_input.token
+            token = parser_input.token
 
         end = parts[-1].end
         self.clean_parenthesis_nodes(parts)
-        return OrNode(start, end, self.parser_input.tokens[start: end + 1], *parts)
+        return OrNode(start, end, parser_input.tokens[start: end + 1], *parts)
 
-    def parse_and(self):
+    def parse_and(self, context, parser_input, error_sink):
-        start = self.parser_input.pos
+        start = parser_input.pos
-        expr = self.parse_not()
+        expr = self.parse_not(context, parser_input, error_sink)
-        token = self.parser_input.token
+        token = parser_input.token
         if token.type != TokenKind.IDENTIFIER or token.value != "and":
             return expr
 
         parts = [expr]
         while token.type == TokenKind.IDENTIFIER and token.value == "and":
-            self.parser_input.next_token()
+            parser_input.next_token()
-            expr = self.parse_not()
+            expr = self.parse_not(context, parser_input, error_sink)
             if expr is None:
-                self.add_error(UnexpectedEofParsingError("When parsing 'and'"))
+                error_sink.add_error(UnexpectedEofParsingError("When parsing 'and'"))
-                end = self.parser_input.pos
+                end = parser_input.pos
                 self.clean_parenthesis_nodes(parts)
-                return AndNode(start, end, self.parser_input.tokens[start: end + 1], *parts)
+                return AndNode(start, end, parser_input.tokens[start: end + 1], *parts)
             parts.append(expr)
-            token = self.parser_input.token
+            token = parser_input.token
 
         end = parts[-1].end
         self.clean_parenthesis_nodes(parts)
-        return AndNode(start, end, self.parser_input.tokens[start: end + 1], *parts)
+        return AndNode(start, end, parser_input.tokens[start: end + 1], *parts)
 
-    def parse_not(self):
+    def parse_not(self, context, parser_input, error_sink):
-        token = self.parser_input.token
+        token = parser_input.token
-        start = self.parser_input.pos
+        start = parser_input.pos
         if token.type == TokenKind.IDENTIFIER and token.value == "not":
-            self.parser_input.next_token()
+            parser_input.next_token()
-            parsed = self.parse_not()
+            parsed = self.parse_not(context, parser_input, error_sink)
             node = parsed.node if isinstance(parsed, ParenthesisNode) else parsed
             return NotNode(start,
                            parsed.end,
-                           self.parser_input.tokens[start: parsed.end + 1],
+                           parser_input.tokens[start: parsed.end + 1],
                            node)
         else:
-            return self.parse_names()
+            return self.parse_names(context, parser_input, error_sink)
 
-    def parse_names(self):
+    def parse_names(self, context, parser_input, error_sink):
 
         def stop():
             return token.type == TokenKind.EOF or \
                    paren_count == 0 and token.type == TokenKind.RPAR or \
                    token.type == TokenKind.IDENTIFIER and token.value in ("and", "or", "not")
 
-        token = self.parser_input.token
+        token = parser_input.token
         if token.type == TokenKind.EOF:
             return None
 
         if token.type == TokenKind.LPAR:
-            start = self.parser_input.pos
+            start = parser_input.pos
-            self.parser_input.next_token()
+            parser_input.next_token()
-            expr = self.parse_or()
+            expr = self.parse_or(context, parser_input, error_sink)
-            token = self.parser_input.token
+            token = parser_input.token
             if token.type != TokenKind.RPAR:
-                self.error_sink.append(
+                error_sink.add_error(
                     UnexpectedTokenParsingError(f"Unexpected token '{token}'", token, [TokenKind.RPAR]))
                 return expr
-            end = self.parser_input.pos
+            end = parser_input.pos
-            self.parser_input.next_token()
+            parser_input.next_token()
             return ParenthesisNode(start, end, None, expr)
 
-        buffer = []
         paren_count = 0
         last_paren = None
-        start = self.parser_input.pos
+        start = parser_input.pos
+        end = parser_input.pos
+        last_is_whitespace = False
         while not stop():
-            buffer.append(token)
+            last_is_whitespace = token.type == TokenKind.WHITESPACE
+            end += 1
             if token.type == TokenKind.LPAR:
                 last_paren = token
                 paren_count += 1
             if token.type == TokenKind.RPAR:
                 paren_count -= 1
-            self.parser_input.next_token(False)
+            parser_input.next_token(False)
-            token = self.parser_input.token
+            token = parser_input.token
 
-        if len(buffer) == 0:
+        if last_is_whitespace:
+            end -= 1
+
+        if start == end:
             if token.type != TokenKind.RPAR:
-                self.error_sink.append(LeftPartNotFoundError())
+                error_sink.add_error(LeftPartNotFoundError())
             return None
 
         if paren_count != 0:
-            self.error_sink.append(ParenthesisMismatchError(last_paren))
+            error_sink.add_error(ParenthesisMismatchError(last_paren))
             return None
 
-        if buffer[-1].type == TokenKind.WHITESPACE:
+        if self.expr_parser:
-            buffer.pop()
+            new_parsing_input = ParserInput(
-
+                None,
-        end = start + len(buffer) - 1
+                tokens=parser_input.tokens,
-        return NameExprNode(start, end, buffer)
+                length=parser_input.length,
+                start=start,
+                end=end - 1,
+                yield_oef=False).reset()
+            new_parsing_input.next_token()
+            return self.expr_parser.parse_input(context, new_parsing_input, error_sink)
+        else:
+            return NameExprNode(start, end - 1, parser_input.tokens[start:end])
 
     def compile_conjunctions(self, context, conjunctions, who):
         """

src/parsers/PythonParser.py

@@ -6,7 +6,7 @@ import core.utils
 from core.builtin_concepts import BuiltinConcepts
 from core.sheerka.services.SheerkaExecute import ParserInput
 from core.tokenizer import TokenKind
-from parsers.BaseParser import BaseParser, Node, ParsingError
+from parsers.BaseParser import BaseParser, Node, ParsingError, BaseParserInputParser
 
 log = logging.getLogger(__name__)
 
@@ -107,7 +107,7 @@ class PythonGetNamesVisitor(ast.NodeVisitor):
         self.names.add(node.id)
 
 
-class PythonParser(BaseParser):
+class PythonParser(BaseParserInputParser):
     """
     Parse Python scripts
     """
@@ -116,7 +116,7 @@ class PythonParser(BaseParser):
 
     def __init__(self, **kwargs):
 
-        BaseParser.__init__(self, PythonParser.NAME, 50)
+        BaseParserInputParser.__init__(self, PythonParser.NAME, 50)
         self.source = kwargs.get("source", "<undef>")
 
     def parse(self, context, parser_input: ParserInput):

src/parsers/PythonWithConceptsParser.py

@@ -2,13 +2,13 @@ from core.builtin_concepts import BuiltinConcepts
 from core.builtin_helpers import CreateObjectIdentifiers
 from parsers.BaseNodeParser import ConceptNode, RuleNode, VariableNode
 from parsers.BaseNodeParser import SourceCodeWithConceptNode
-from parsers.BaseParser import BaseParser
+from parsers.BaseParser import BaseParser, BaseParserInputParser
 from parsers.UnrecognizedNodeParser import UnrecognizedNodeParser
 
 unrecognized_nodes_parser = UnrecognizedNodeParser()
 
 
-class PythonWithConceptsParser(BaseParser):
+class PythonWithConceptsParser(BaseParserInputParser):
     def __init__(self, **kwargs):
         super().__init__("PythonWithConcepts", 20)
 

src/parsers/RelationalOperatorParser.py

@@ -4,12 +4,12 @@ from core.builtin_concepts_ids import BuiltinConcepts
 from core.sheerka.services.SheerkaExecute import ParserInput, SheerkaExecute
 from core.tokenizer import TokenKind, Token
 from core.utils import get_text_from_tokens
-from parsers.BaseParser import UnexpectedTokenParsingError, BaseExprParser
+from parsers.BaseParser import UnexpectedTokenParsingError, BaseExprParser, BaseParserInputParser
 from parsers.expressions import ComparisonNode, ParenthesisMismatchError, NameExprNode, ComparisonType, VariableNode, \
     ParenthesisNode, LeftPartNotFoundError
 
 
-class RelationalOperatorParser(BaseExprParser):
+class RelationalOperatorParser(BaseParserInputParser):
     """
     Parses xxx (== | > | < | >= | <= | != | in | not in) yyy
     Nothing else
@@ -53,7 +53,7 @@ class RelationalOperatorParser(BaseExprParser):
         if isinstance(node, ParenthesisNode):
             node = node.node
 
-        value = self.get_return_value_body(context.sheerka, self.parser_input.as_text(), node, node)
+        value = self.get_return_value_body(context.sheerka, self.parser_input.as_text(), node, node, self.error_sink)
 
         ret = self.sheerka.ret(
             self.name,

src/parsers/RuleParser.py

@@ -2,7 +2,7 @@ from core.builtin_concepts import BuiltinConcepts
 from core.rule import Rule
 from core.sheerka.services.SheerkaExecute import ParserInput
 from core.tokenizer import TokenKind
-from parsers.BaseParser import BaseParser, ParsingError, UnexpectedTokenParsingError
+from parsers.BaseParser import BaseParser, ParsingError, UnexpectedTokenParsingError, BaseParserInputParser
 
 
 class RuleNotFoundError(ParsingError):
@@ -14,7 +14,7 @@ class RuleNotFoundError(ParsingError):
         return f"RuleNotFoundError(id={self.id}, key={self.key}"
 
 
-class RuleParser(BaseParser):
+class RuleParser(BaseParserInputParser):
     """
     Tries to recognize rules
     """
@@ -22,7 +22,7 @@ class RuleParser(BaseParser):
     NAME = "Rule"
 
     def __init__(self, **kwargs):
-        BaseParser.__init__(self, RuleParser.NAME, 80)
+        BaseParserInputParser.__init__(self, RuleParser.NAME, 80)
 
     def parse(self, context, parser_input: ParserInput):
         """

src/parsers/UnrecognizedNodeParser.py

@@ -4,7 +4,7 @@ import core.utils
 from core.builtin_concepts import BuiltinConcepts
 from core.builtin_helpers import only_successful, get_lexer_nodes, update_compiled
 from parsers.BaseNodeParser import ConceptNode, UnrecognizedTokensNode, SourceCodeNode, SourceCodeWithConceptNode
-from parsers.BaseParser import BaseParser, ParsingError
+from parsers.BaseParser import BaseParser, ParsingError, BaseParserInputParser
 from parsers.BnfNodeParser import BnfNodeParser
 from parsers.SequenceNodeParser import SequenceNodeParser
 from parsers.SyaNodeParser import SyaNodeParser
@@ -22,7 +22,7 @@ class CannotParseError(ParsingError):
     unrecognized: UnrecognizedTokensNode
 
 
-class UnrecognizedNodeParser(BaseParser):
+class UnrecognizedNodeParser(BaseParserInputParser):
     """
     This parser comes after the other NodeParsers (Atom, Bnf or Sya)
     It will try to resolve all UnrecognizedTokensNode.

tests/parsers/test_BaseParser.py

@@ -1,7 +1,7 @@
 import pytest
 
 from core.tokenizer import Tokenizer
-from parsers.BaseParser import BaseParser
+from parsers.BaseParser import BaseParser, BaseParserInputParser
 
 
 @pytest.mark.parametrize("tokens, expected", [
@@ -17,4 +17,4 @@ from parsers.BaseParser import BaseParser
     (list(Tokenizer(" a ", yield_eof=False)), (1, 1)),
 ])
 def test_i_can_get_tokens_boundaries(tokens, expected):
-    assert BaseParser.get_tokens_boundaries(tokens) == expected
+    assert BaseParserInputParser.get_tokens_boundaries(tokens) == expected

tests/parsers/test_ExpressionParser.py

@@ -3,10 +3,11 @@ import pytest
 from core.builtin_concepts_ids import BuiltinConcepts
 from core.sheerka.services.SheerkaExecute import ParserInput
 from core.tokenizer import Tokenizer
+from parsers.BaseParser import ErrorSink
 from parsers.ExpressionParser import ExpressionParser
 from parsers.expressions import VariableNode
 from tests.TestUsingMemoryBasedSheerka import TestUsingMemoryBasedSheerka
-from tests.parsers.parsers_utils import get_expr_node_from_test_node, VAR, EXPR
+from tests.parsers.parsers_utils import get_expr_node_from_test_node, VAR, EXPR, AND
 
 
 class TestExpressionParser(TestUsingMemoryBasedSheerka):
@@ -17,9 +18,10 @@ class TestExpressionParser(TestUsingMemoryBasedSheerka):
 
     def input_parser_with_source(self, source):
         sheerka, context, parser = self.init_parser()
-        parser.reset_parser(context, ParserInput(source))
+        error_sink = ErrorSink()
-        parser.parser_input.next_token()
+        parser_input = ParserInput(source)
-        return sheerka, context, parser
+        parser.reset_parser_input(parser_input, error_sink)
+        return sheerka, context, parser, parser_input, error_sink
 
     def test_i_can_detect_empty_expression(self):
         sheerka, context, parser = self.init_parser()
@@ -29,17 +31,18 @@ class TestExpressionParser(TestUsingMemoryBasedSheerka):
         assert sheerka.isinstance(res.body, BuiltinConcepts.IS_EMPTY)
 
     @pytest.mark.parametrize("expression, expected", [
-        ("var1 + var 2", EXPR("var1 + var 2")),
+        ("var1 + var2", EXPR("var1 + var2")),
         ("variable", VAR("variable")),
         ("var.attr", VAR("var.attr")),
+        ("var1 and var2", AND(VAR("var1"), VAR("var2")))
     ])
     def test_i_can_parse_input(self, expression, expected):
-        sheerka, context, parser = self.input_parser_with_source(expression)
+        sheerka, context, parser, parser_input, error_sink = self.input_parser_with_source(expression)
         expected = get_expr_node_from_test_node(expression, expected)
 
-        parsed = parser.parse_input()
+        parsed = parser.parse_input(context, parser_input, error_sink)
 
-        assert not parser.has_error
+        assert not error_sink.has_error
         assert parsed == expected
 
     @pytest.mark.parametrize("expression", [
@@ -47,10 +50,10 @@ class TestExpressionParser(TestUsingMemoryBasedSheerka):
         "var . attr1 . attr2",
     ])
     def test_i_can_parse_variable(self, expression):
-        sheerka, context, parser = self.input_parser_with_source(expression)
+        sheerka, context, parser, parser_input, error_sink = self.input_parser_with_source(expression)
-        parsed = parser.parse_input()
+        parsed = parser.parse_input(context, parser_input, error_sink)
 
-        assert not parser.has_error
+        assert not error_sink.has_error
         assert isinstance(parsed, VariableNode)
         assert parsed.name == "var"
         assert parsed.attributes == ["attr1", "attr2"]
@@ -60,9 +63,9 @@ class TestExpressionParser(TestUsingMemoryBasedSheerka):
 
         expression = "do not care var1 + var2 do not care either"
         parser_input = ParserInput("text", list(Tokenizer(expression, yield_eof=False)), start=6, end=10)
+        error_sink = ErrorSink()
+        parser.reset_parser_input(parser_input, error_sink)
+        parsed = parser.parse_input(context, parser_input, error_sink)
 
-        parser.reset_parser(context, parser_input)
+        assert not error_sink.has_error
-        parsed = parser.parse_input()
-
-        assert not parser.has_error
         assert parsed == get_expr_node_from_test_node(expression, EXPR("var1 + var2"))