callback ( head quot: ( callback-env -- ? ) -- )

Vocabulary

logic

Inputs

head	an array
quot	a quotation

Outputs

None

Word description

Set the quotation to be called. Such quotations take an environment which holds the binding of logic variables, and returns t or f as a result of execution. To retrieve the values of logic variables in the environment, use of or at.

Examples

LOGIC-PRED: N_>_0 { N_>_0 N } [ N of 0 > ] callback

See also

callbacks

Definition

USING: accessors kernel logic.private sequences ;

IN: logic

:: callback ( head quot: ( callback-env -- ? ) -- )
    head def>goal :> head-goal head-goal pred>>
    [ { head-goal quot } suffix! ] change-defs drop ;