REBOL 3 Functions: collect

collect body /into output

Evaluates a block, storing values via KEEP function, and returns block of collected values.

Arguments:

body [block!] - Block to evaluate

Refinements:

/into - Insert into a buffer instead (returns position after insert)

output [series!] - The buffer series (modified)

Description

Using the internal keep function, will collect values spread around a block to be stored in another block and returned:

collect [keep 1 2 3 keep 4]
[1 4]

Can also be used with the parse function:

collect [
    parse [a b c d e] [
        any ['c | 'e | set w word! (keep w)]
    ]
]
[a b d]

Blocks are collected and appended to the output as a series of values:

collect [keep 1 keep [2 3]]
[1 2 3]

The keep function has a refinement /only to append blocks as blocks to the output:

collect [keep 1 keep/only [2 3]]
[1 [2 3]]