split1-when ( ... seq quot: ( ... elt -- ... ? ) -- ... before after ) (original) (raw)
split1-when ( ... seq quot: ( ... elt -- ... ? ) -- ... before after )
Factor handbook » The language » Collections » Sequence operations » Splitting sequences
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Vocabulary
splitting
Inputs
| seq | a sequence |
|---|---|
| quot | a quotation with stack effect ( ... elt -- ... ? ) |
Outputs
| before | a new sequence |
|---|---|
| after | a new sequence |
Word description
Splits seq at the first occurrence of an element for which quot gives a true output and outputs the pieces before and after the split.
Definition
USING: kernel math sequences ;
: split1-when
( ... seq quot: ( ... elt -- ... ? ) -- ... before after )
[ find drop ] keepd swap [ dup 1 + rot snip ] [ f ] if* ;
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