Package nltk :: Package sem :: Module logic :: Class LogicParser

type LogicParser

object --+
         |
        LogicParser

Known Subclasses:

A lambda calculus expression parser.

Instance Methods

[hide private]

__init__(self, type_check=False)

source code

parse(self, data, signature=None)
Parse the expression.

source code

process(self, data)
Split the data into tokens

source code

process_quoted_token(self, data_idx, data)

source code

get_all_symbols(self)
This method exists to be overridden

source code

inRange(self, location)
Return TRUE if the given location is within the buffer

source code

token(self, location=None)
Get the next waiting token.

source code

isvariable(self, tok)

source code

parse_Expression(self, context)
Parse the next complete expression from the stream and return it.

source code

handle(self, tok, context)
This method is intended to be overridden for logics that use different operators or expressions

source code

attempt_adjuncts(self, expression, context)

source code

handle_negation(self, tok, context)

source code

make_NegatedExpression(self, expression)

source code

handle_variable(self, tok, context)

source code

get_next_token_variable(self, description)

source code

handle_lambda(self, tok, context)

source code

handle_quant(self, tok, context)

source code

get_QuantifiedExpression_factory(self, tok)
This method serves as a hook for other logic parsers that have different quantifiers

source code

make_QuanifiedExpression(self, factory, variable, term)

source code

handle_open(self, tok, context)

source code

attempt_EqualityExpression(self, expression, context)
Attempt to make an equality expression.

source code

make_EqualityExpression(self, first, second)
This method serves as a hook for other logic parsers that have different equality expression classes

source code

attempt_BooleanExpression(self, expression, context)
Attempt to make a boolean expression.

source code

get_BooleanExpression_factory(self, tok)
This method serves as a hook for other logic parsers that have different boolean operators

source code

make_BooleanExpression(self, factory, first, second)

source code

attempt_ApplicationExpression(self, expression, context)
Attempt to make an application expression.

source code

make_ApplicationExpression(self, function, argument)

source code

make_VariableExpression(self, name)

source code

make_LambdaExpression(self, variable, term)

source code

has_priority(self, operation, context)

source code

assertNextToken(self, expected)

source code

assertToken(self, tok, expected)

source code

__repr__(self)

source code

ensure_abstractable(self, tok)

Instance Variables

[hide private]

type_check
A list of tuples of quote characters.

Method Details

[hide private]

init(self, type_check=False)
(Constructor)

source code

Parameters:

type_check - boolean should type checking be performed? to their types.

Overrides: object.__init__

parse(self, data, signature=None)

source code

Parse the expression.

Parameters:

data - str for the input to be parsed
signature - dict<str, str> that maps variable names to type strings

Returns:

a parsed Expression

token(self, location=None)

source code

Get the next waiting token. If a location is given, then return the token at currentIndex+location without advancing currentIndex; setting it gives lookahead/lookback capability.

attempt_EqualityExpression(self, expression, context)

source code

Attempt to make an equality expression. If the next token is an equality operator, then an EqualityExpression will be returned. Otherwise, the parameter will be returned.

attempt_BooleanExpression(self, expression, context)

source code

Attempt to make a boolean expression. If the next token is a boolean operator, then a BooleanExpression will be returned. Otherwise, the parameter will be returned.

attempt_ApplicationExpression(self, expression, context)

source code

Attempt to make an application expression. The next tokens are a list of arguments in parens, then the argument expression is a function being applied to the arguments. Otherwise, return the argument expression.

repr(self)
(Representation operator)

source code

Overrides: object.__repr__: (inherited documentation)

Instance Variable Details

[hide private]

type_check

A list of tuples of quote characters. The 4-tuple is comprised of the start character, the end character, the escape character, and a boolean indicating whether the quotes should be included in the result. Quotes are used to signify that a token should be treated as atomic, ignoring any special characters within the token. The escape character allows the quote end character to be used within the quote. If True, the boolean indicates that the final token should contain the quote and escape characters. This method exists to be overridden

type LogicParser

__init__(self, type_check=False) (Constructor)

parse(self, data, signature=None)

token(self, location=None)

attempt_EqualityExpression(self, expression, context)

attempt_BooleanExpression(self, expression, context)

attempt_ApplicationExpression(self, expression, context)

__repr__(self) (Representation operator)

type_check

init(self, type_check=False)
(Constructor)

repr(self)
(Representation operator)