nquery ( goal-def/defs n/f -- bindings-array/success? )

Vocabulary

logic

Inputs

goal-def/defs	a goal def or an array of goal defs
n/f	the highest number of responses

Outputs

bindings-array/success?

anser

Word description

The version of query that limits the number of responses. Specify a number greater than or equal to 1. If f is given instead of a number as n/f, there is no limit to the number of answers. That is, the behavior is the same as query.

See also

query

Definition

USING: accessors arrays assocs combinators.short-circuit
continuations formatting kernel logic.private math namespaces
sequences ;

IN: logic

:: nquery ( goal-def/defs n/f -- bindings-array/success? )
    *trace?* get-global :> trace? 0 :> n! f :> success?!
    V{ } clone :> bindings <env> :> env goal-def/defs
    replace-'__' normalize [ def>goal ] map
    env f <cut> <resolver> :> resolver [
        [
            resolver next dup [
                resolver env>> table>> keys
                [ get NORMAL-LOGIC-VAR? ] filter
                [ dup env at ] H{ } map>assoc trace? get-global
                [ dup [ "%u: %u\n" printf ] assoc-each ] when
                bindings push t success?! n/f
                [ n 1 + n! n n/f >= [ return ] when ] when
            ] when
        ] loop
    ] with-return bindings dup
    { [ empty? ] [ first keys empty? ] } 1||
    [ drop success? ] [ >array ] if ;