From f14c933df16ee0faee6bff8004da4e5d3e1caf07 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= Date: Fri, 16 Feb 2018 18:31:46 +0100 Subject: Add (guix glob). * guix/glob.scm, tests/glob.scm: New files. * Makefile.am (MODULES): Add guix/glob.scm. (SCM_TESTS): Add tests/glob.scm. --- guix/glob.scm | 97 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 guix/glob.scm (limited to 'guix/glob.scm') diff --git a/guix/glob.scm b/guix/glob.scm new file mode 100644 index 0000000000..4fc5173ac0 --- /dev/null +++ b/guix/glob.scm @@ -0,0 +1,97 @@ +;;; GNU Guix --- Functional package management for GNU +;;; Copyright © 2018 Ludovic Courtès +;;; +;;; This file is part of GNU Guix. +;;; +;;; GNU Guix is free software; you can redistribute it and/or modify it +;;; under the terms of the GNU General Public License as published by +;;; the Free Software Foundation; either version 3 of the License, or (at +;;; your option) any later version. +;;; +;;; GNU Guix is distributed in the hope that it will be useful, but +;;; WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Guix. If not, see . + +(define-module (guix glob) + #:use-module (ice-9 match) + #:export (compile-glob-pattern + glob-match?)) + +;;; Commentary: +;;; +;;; This is a minimal implementation of "glob patterns" (info "(libc) +;;; Globbbing"). It is currently limited to simple patterns and does not +;;; support braces and square brackets, for instance. +;;; +;;; Code: + +(define (wildcard-indices str) + "Return the list of indices in STR where wildcards can be found." + (let loop ((index 0) + (result '())) + (if (= index (string-length str)) + (reverse result) + (loop (+ 1 index) + (case (string-ref str index) + ((#\? #\*) (cons index result)) + (else result)))))) + +(define (compile-glob-pattern str) + "Return an sexp that represents the compiled form of STR, a glob pattern +such as \"foo*\" or \"foo??bar\"." + (define flatten + (match-lambda + (((? string? str)) str) + (x x))) + + (let loop ((index 0) + (indices (wildcard-indices str)) + (result '())) + (match indices + (() + (flatten (cond ((zero? index) + (list str)) + ((= index (string-length str)) + (reverse result)) + (else + (reverse (cons (string-drop str index) + result)))))) + ((wildcard-index . rest) + (let ((wildcard (match (string-ref str wildcard-index) + (#\? '?) + (#\* '*)))) + (match (substring str index wildcard-index) + ("" (loop (+ 1 wildcard-index) + rest + (cons wildcard result))) + (str (loop (+ 1 wildcard-index) + rest + (cons* wildcard str result))))))))) + +(define (glob-match? pattern str) + "Return true if STR matches PATTERN, a compiled glob pattern as returned by +'compile-glob-pattern'." + (let loop ((pattern pattern) + (str str)) + (match pattern + ((? string? literal) (string=? literal str)) + (((? string? one)) (string=? one str)) + (('*) #t) + (('?) (= 1 (string-length str))) + (() #t) + (('* suffix . rest) + (match (string-contains str suffix) + (#f #f) + (index (loop rest + (string-drop str + (+ index (string-length suffix))))))) + (('? . rest) + (and (>= (string-length str) 1) + (loop rest (string-drop str 1)))) + ((prefix . rest) + (and (string-prefix? prefix str) + (loop rest (string-drop str (string-length prefix)))))))) -- cgit v1.2.3