concat ( seq -- newseq )
Factor handbook » The language » Collections » Sequence operations » Appending sequences

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Vocabulary
sequences

Inputs

seq	a sequence

Outputs

newseq

a sequence

Word description
Concatenates a sequence of sequences together into one sequence. If seq is empty, outputs { }, otherwise the resulting sequence is of the same class as the first element of seq.

Errors
Throws an error if one of the sequences in seq contains elements not permitted in sequences of the same class as the first element of seq.

See also
join, join-as, concat-as

Definition

USING: kernel ;

IN: sequences

: concat ( seq -- newseq )
    [ { } ] [ dup first concat-as ] if-empty ;