HINTS:
Factor handbook » The implementation » Optimizing compiler » Compiler specialization hints

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specialized-def ( word -- quot )

Vocabulary
hints

Inputs
None

Outputs
None

Word description
Defines specialization hints for a word or a method.

Each sequence in the list will cause a specialized version of the word to be compiled. Classes are tested for using their predicate, and literals are tested using eq?.

Examples
The append word has a specializer for the very common case where two strings or two arrays are appended:

USING: arrays hints sequences strings ; HINTS: append { string string } { array array } ;

Specializers can also be defined on methods:

USING: assocs hashtables hints kernel sequences ; GENERIC: count-occurrences ( elt obj -- n ) M: sequence count-occurrences [ = ] with count ; M: assoc count-occurrences swap [ = nip ] curry assoc-filter assoc-size ; HINTS: M\ sequence count-occurrences { object array } ; HINTS: M\ assoc count-occurrences { object hashtable } ;

Definition

USING: accessors definitions kernel parser sequences words ;

IN: hints

SYNTAX: HINTS:
    scan-object dup wrapper? [ wrapped>> ] when
    [ changed-definition ]
    [ subwords [ changed-definition ] each ]
    [ parse-definition { } like set-specializer ] tri ;