at* ( key assoc -- value/f ? )
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Vocabulary
assocs

Inputs

key	an object to look up in the assoc
assoc	an assoc

Outputs

value/f	the value associated to the key, or f if the key is not present in the assoc
?	a boolean indicating if the key was present

Generic word contract
Looks up the value associated with a key. The boolean flag can decide between the case of a missing value, and a value of f.

See also
at, key?, ?at, of, ?of

Definition

IN: assocs

GENERIC: at* ( key assoc -- value/f ? )

Methods

USING: assocs kernel sequences xml.data ;

M: attrs at* attr@ nip [ second t ] [ f f ] if* ;


USING: accessors assocs biassocs ;

M: biassoc at* from>> at* ; inline


USING: accessors assocs bitcask bitcask.private io
io.encodings.binary io.files kernel ;

M:: bitcask at* ( key bitcask -- value/f ? )
    key bitcask index>> at* [
        bitcask path>> binary
        [ seek-absolute seek-input read-entry ] with-file-reader
    ] [ drop f f ] if ;


USING: accessors assocs cache kernel ;

M: cache-assoc at*
    assoc>> at* [ [ 0 >>age value>> ] ?call ] dip ;


USING: accessors assocs logic.private ;

M: callback-env at* env>> at* ; inline


USING: accessors assocs kernel sequences sequences.private ;

M: enumerated at*
    seq>> 2dup bounds-check? [ nth-unsafe t ] [ 2drop f f ] if ;
    inline


USING: assocs env environment kernel ;

M: env at* drop os-env dup >boolean ;


USING: assocs kernel ;

M: f at* 2drop f f ; inline


USING: accessors assocs kernel kernel.private namespaces.private
;

M: global-hashtable at*
    boxes>> at*
    [ { global-box } declare value>> t ] [ drop f f ] if ;
    inline


USING: assocs hashtables hashtables.private kernel math.private
slots.private ;

M: hashtable at*
    key@ [ 3 fixnum+fast slot t ] [ 2drop f f ] if ;


USING: assocs xmode.keyword-map ;

M: keyword-map at* handle-case at* ;


USING: accessors assocs kernel linked-assocs sequences.private ;

M: linked-assoc at*
    assoc>> at* [ [ obj>> second-unsafe ] when ] keep ;


USING: accessors assocs classes classes.tuple combinators kernel
logic.private sequences ;

M: logic-env at*
    dereference {
        {
            [ over logic-goal? ]
            [ [ [ pred>> ] [ args>> ] bi ] dip at <goal> t ]
        }
        {
            [ over tuple? ]
            [
                [ at ] curry [ [ tuple-slots ] ] dip
                [ map ] curry compose
                [ class-of slots>tuple ] bi t
            ]
        }
        { [ over sequence? ] [ [ at ] curry map t ] }
        [ drop t ]
    } cond ; inline


USING: accessors assocs deques dlists kernel lru-cache
sequences.private ;

M: lru-cache at*
    [ assoc>> at* ] [ dlist>> dup ] bi
    [ [ delete-node ] curry ] dip [ push-node-back ] curry
    [ [ obj>> second-unsafe ] tri ] 2curry [ when ] curry keep ;


USING: accessors assocs kernel mirrors slots slots.private ;

M: mirror at*
    [ nip object>> ] [ object-slots slot-named ] 2bi
    [ offset>> slot t ] [ drop f f ] if* ;


USING: assocs kernel sequences sequences.n-based
sequences.n-based.private sequences.private ;

M: n-based-assoc at*
    n-based@ 2dup bounds-check?
    [ nth-unsafe t ] [ 2drop f f ] if ;


USING: assocs classes.tuple kernel named-tuples slots.private ;

M: named-tuple at*
    [ nip ] [ ?offset-of-slot ] 2bi [ slot t ] [ drop f f ] if*
    ;


USING: accessors assocs kernel pairs ;

M: pair at*
    [ value>> t ] [ [ at* ] [ 2drop f f ] if-hash ] if-key ;
    inline


USING: accessors assocs kernel math persistent.hashtables
persistent.hashtables.nodes ;

M: persistent-hash at*
    [ dup hashcode >fixnum ] [ root>> ] bi* (entry-at) dup
    [ value>> t ] [ f ] if ;


USING: assocs quadtrees quadtrees.private ;

M: quadtree at* at-point ;


USING: assocs kernel redis ;

M: redis at* [ redis-get dup >boolean ] with-redis ;


USING: assocs assocs.private kernel sequences ;

M: sequence at* search-alist [ second t ] [ f ] if ;


USING: accessors assocs kernel trees.splay trees.splay.private ;

M: splay at*
    dup root>>
    [ get-splay [ dup [ value>> ] when ] dip ] [ 2drop f f ] if
    ;


USING: accessors alien arrays assocs classes.struct.prettyprint
combinators combinators.short-circuit kernel math sequences ;

M: struct-mirror at*
    object>> {
        { [ over "underlying" = ] [ nip >c-ptr t ] }
        {
            [ over { [ array? ] [ length 1 >= ] } 1&& ]
            [ swap first get-struct-slot ]
        }
        [ 2drop f f ]
    } cond ;


USING: accessors assocs kernel xml.data ;

M: tag at* [ attrs>> ] call \ at* execute ;


USING: accessors alien.c-types alien.data assocs kernel
sequences serialize tokyo.abstractdb tokyo.alien.tcadb
tokyo.alien.tcutil tokyo.utils ;

M: tokyo-abstractdb at*
    handle>> swap object>bytes dup length 0 int <ref> tcadbget
    [ [ memory>object ] [ tcfree ] bi t ] [ f f ] if* ;


USING: accessors alien.c-types alien.data assocs kernel
sequences serialize tokyo.alien.tcrdb tokyo.alien.tcutil
tokyo.remotedb tokyo.utils ;

M: tokyo-remotedb at*
    handle>> swap object>bytes dup length 0 int <ref> tcrdbget
    [ [ memory>object ] [ tcfree ] bi t ] [ f f ] if* ;


USING: accessors assocs trees trees.private ;

M: tree at* root>> node-at* ;


USING: accessors assocs kernel math vlists vlists.private ;

M: valist at*
    vlist>> >vlist< [ 2 - ] [ underlying>> ] bi* valist-at ;


USING: assocs hashtables.wrapped hashtables.wrapped.private ;

M: wrapped-hashtable at* wrapper@ at* ; inline


USING: arrays assocs combinators.short-circuit kernel math
sequences splitting zim ;

M: zim at*
    [
        [
            "/" split dup
            { [ length 1 > ] [ first length 1 = ] } 1&&
            [ unclip-slice first ] [ f ] if swap "/" join
        ] [ read-entry-url 2array t ] bi*
    ] with-zim ;