Lookaround¶

bcql_py.models.lookaround ¶

Regex-based lookahead and lookbehind assertions require special handling. Note that these occur outside of string literals but are lookarounds on Node values.

LookaheadNode ¶

Bases: BCQLNode

A lookahead assertion: (?=...) (positive) or (?!...) (negative).

Matches a position only if the enclosed query matches (or doesn't match) the tokens that follow.

Attributes:

Name	Type	Description
`positive`	`bool`	`True` for `(?= ...)`, `False` for `(?! ...)`.
`body`	`BCQLNodeUnion`	The sub-query that must (or must not) match ahead.

LookbehindNode ¶

Bases: BCQLNode

A lookbehind assertion: (?<=...) (positive) or (?<!...) (negative).

Matches a position only if the enclosed query matches (or doesn't match) the tokens that precede

Attributes:

Name	Type	Description
`positive`	`bool`	`True` for `(?<=...)`, `False` for `(?<!...)`.
`body`	`BCQLNodeUnion`	The sub-query that must (or must not) match behind