ExpressionTree Class Reference

Parses and evaluates operator expressions like "a AND (b OR NOT c)". More...

Public Member Functions
	__init__ (self, **props)
	configure (self, **props)
	Overrides instance configuration.
	evaluate (self, tree, terminal=None, eager=())
	Returns result of evaluating expression tree.
	format (self, tree, terminal=None)
	Returns expression tree formatted as string.
	parse (self, text, terminal=None)
	Returns an operator expression like "a AND (b OR NOT c)" parsed into a binary tree.

Static Public Attributes
	AND
tuple	BINARIES = (AND, OR)
bool	CASED = False
	ESCAPE
dict	FORMAT_TEMPLATES = {AND: "%s and %s", OR: "%s or %s", NOT: "not %s"}
	IMPLICIT = AND
	LBRACE
	NOT
dict	OPERATORS = {AND: (lambda a, b: a and b), OR: (lambda a, b: a or b), NOT: lambda a: not a}
	OR
	QUOTES
dict	RANKS = {VAL: 1, NOT: 2, AND: 3, OR: 4}
	RBRACE
	SEPARATORS = WHITESPACE + LBRACE + RBRACE
dict	SHORTCIRCUITS = {AND: False, OR: True}
tuple	UNARIES = (NOT, )
	VAL
	VOID = None
	WHITESPACE

Detailed Description

Parses and evaluates operator expressions like "a AND (b OR NOT c)".

Operands can be quoted strings, '\' can be used to escape quotes within the string. Operators are case-insensitive.

Definition at line 579 of file search.py.

Constructor & Destructor Documentation

__init__()

__init__	(		self,
		**	props
	)

Parameters

props

class property overrides, case-insensitive, e.g. cased=False

Definition at line 600 of file search.py.

Member Function Documentation

configure()

configure	(		self,
		**	props
	)

Overrides instance configuration.

Parameters

props

class property overrides, case-insensitive, e.g. cased=False

Definition at line 610 of file search.py.

evaluate()

evaluate	(		self,
			tree,
			terminal = None,
			eager = ()
	)

Returns result of evaluating expression tree.

Parameters

tree	expression tree structure as given by parse()
terminal	callback(value) to evaluate value nodes with, if not using value directly
eager	operators where to evaluate both operands in full, despite short-circuit

Definition at line 626 of file search.py.

format()

format	(		self,
			tree,
			terminal = None
	)

Returns expression tree formatted as string.

Parameters

tree	expression tree structure as given by parse()
terminal	callback(value) to format value nodes with, if not using value directly

Definition at line 647 of file search.py.

parse()

parse	(		self,
			text,
			terminal = None
	)

Returns an operator expression like "a AND (b OR NOT c)" parsed into a binary tree.

Binary tree like ["AND", [["VAL", "a"], ["OR", [["VAL", "b"], ["NOT", [["VAL", "c"]]]]]]]. Raises on invalid expression.

Parameters

terminal

callback(text) returning node value for operands, if not using plain text

Definition at line 669 of file search.py.

Member Data Documentation

AND

AND

static

Definition at line 583 of file search.py.

BINARIES

tuple BINARIES = (AND, OR)

static

Definition at line 588 of file search.py.

CASED

bool CASED = False

static

Definition at line 585 of file search.py.

ESCAPE

ESCAPE

static

Definition at line 581 of file search.py.

FORMAT_TEMPLATES

dict FORMAT_TEMPLATES = {AND: "%s and %s", OR: "%s or %s", NOT: "not %s"}

static

Definition at line 593 of file search.py.

IMPLICIT

IMPLICIT = AND

static

Definition at line 586 of file search.py.

LBRACE

LBRACE

static

Definition at line 581 of file search.py.

NOT

NOT

static

Definition at line 583 of file search.py.

OPERATORS

dict OPERATORS = {AND: (lambda a, b: a and b), OR: (lambda a, b: a or b), NOT: lambda a: not a}

static

Definition at line 589 of file search.py.

OR

OR

static

Definition at line 583 of file search.py.

QUOTES

QUOTES

static

Definition at line 581 of file search.py.

RANKS

dict RANKS = {VAL: 1, NOT: 2, AND: 3, OR: 4}

static

Definition at line 590 of file search.py.

RBRACE

RBRACE

static

Definition at line 581 of file search.py.

SEPARATORS

SEPARATORS = WHITESPACE + LBRACE + RBRACE

static

Definition at line 582 of file search.py.

SHORTCIRCUITS

dict SHORTCIRCUITS = {AND: False, OR: True}

static

Definition at line 592 of file search.py.

UNARIES

tuple UNARIES = (NOT, )

static

Definition at line 587 of file search.py.

VAL

VAL

static

Definition at line 583 of file search.py.

VOID

VOID = None

static

Definition at line 594 of file search.py.

WHITESPACE

WHITESPACE

static

Definition at line 581 of file search.py.

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The documentation for this class was generated from the following file:

• grepros/search.py