join-as ( seq glue exemplar -- newseq )
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Vocabulary
sequences

Inputs

seq	a sequence
glue	a sequence
exemplar	a sequence

Outputs

newseq

a sequence

Word description
Concatenates a sequence of sequences together into one sequence, placing a copy of glue between each pair of sequences. The resulting sequence is of the same class as glue.

Notes
If the glue sequence is empty, this word calls concat-as.

Examples
Join a list of strings as a string buffer:

USING: sequences prettyprint ; { "a" "b" "c" } "1" SBUF" " join-as .
SBUF" a1b1c"

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

See also
join, concat, concat-as

Definition

USING: kernel sequences.private ;

IN: sequences

: join-as ( seq glue exemplar -- newseq )
    over empty?
    [ nip concat-as ] [
        [
            2dup joined-length over new-resizable [
                [ [ push-all ] 2curry ]
                [ nip [ push-all ] curry ] 2bi interleave
            ] keep
        ] dip like
    ] if ;