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author | Ludovic Courtès <ludo@gnu.org> | 2013-04-28 21:38:40 +0200 |
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committer | Ludovic Courtès <ludo@gnu.org> | 2013-04-28 23:19:03 +0200 |
commit | 2bcfb9e065ac6abb6abf7ac9a263ba3c4d70124f (patch) | |
tree | 2b68896d8f18ed5b1b67c982f9677c84066b357c /guix/utils.scm | |
parent | 19cb51701266404e023eda5a50c026bccb0dc6a0 (diff) | |
download | gnu-guix-2bcfb9e065ac6abb6abf7ac9a263ba3c4d70124f.tar gnu-guix-2bcfb9e065ac6abb6abf7ac9a263ba3c4d70124f.tar.gz |
utils: Add `string-tokenize*'.
* guix/utils.scm (string-tokenize*): New procedure.
* tests/utils.scm ("string-tokenize*"): New test.
Diffstat (limited to 'guix/utils.scm')
-rw-r--r-- | guix/utils.scm | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/guix/utils.scm b/guix/utils.scm index 3cbed2fd0f..0b09affffd 100644 --- a/guix/utils.scm +++ b/guix/utils.scm @@ -60,6 +60,7 @@ version-compare version>? package-name->name+version + string-tokenize* file-extension call-with-temporary-output-file fold2)) @@ -471,6 +472,33 @@ introduce the version part." (let ((dot (string-rindex file #\.))) (and dot (substring file (+ 1 dot) (string-length file))))) +(define (string-tokenize* string separator) + "Return the list of substrings of STRING separated by SEPARATOR. This is +like `string-tokenize', but SEPARATOR is a string." + (define (index string what) + (let loop ((string string) + (offset 0)) + (cond ((string-null? string) + #f) + ((string-prefix? what string) + offset) + (else + (loop (string-drop string 1) (+ 1 offset)))))) + + (define len + (string-length separator)) + + (let loop ((string string) + (result '())) + (cond ((index string separator) + => + (lambda (offset) + (loop (string-drop string (+ offset len)) + (cons (substring string 0 offset) + result)))) + (else + (reverse (cons string result)))))) + (define (call-with-temporary-output-file proc) "Call PROC with a name of a temporary file and open output port to that file; close the file and delete it when leaving the dynamic extent of this |