[Guile-commits] 01/03: Add string-replace-substring to (ice-9 string-fun)

[Daniel Llorens]

lloda pushed a commit to branch wip-exception-truncate
in repository guile.

commit cf5b4a1db8ad4c1060f08f07113791dd34374266
Author: Daniel Llorens <address@hidden>
Date:   Fri Dec 20 12:53:34 2019 +0100

    Add string-replace-substring to (ice-9 string-fun)
---
 module/ice-9/string-fun.scm | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/module/ice-9/string-fun.scm b/module/ice-9/string-fun.scm
index c27ff84..bef841d 100644
--- a/module/ice-9/string-fun.scm
+++ b/module/ice-9/string-fun.scm
@@ -25,7 +25,8 @@
           separate-fields-discarding-char separate-fields-after-char
           separate-fields-before-char string-prefix-predicate string-prefix=?
           sans-surrounding-whitespace sans-trailing-whitespace
-          sans-leading-whitespace sans-final-newline has-trailing-newline?))
+          sans-leading-whitespace sans-final-newline has-trailing-newline?
+           string-replace-substring))
 
 ;;;;
 ;;;
@@ -278,3 +279,25 @@
 ;;;         (fail parts)
 ;;;         (apply return parts))))
 
+
+
+;;; {String Fun: string-replace-substring}
+;;;
+
+;; By A. Wingo in 
https://lists.gnu.org/archive/html/guile-devel/2014-03/msg00058.html
+
+(define (string-replace-substring s substring replacement)
+  "Replace every instance of @var{substring} in string @var{s} by 
@var{replacement}."
+  (let ((sublen (string-length substring)))
+    (with-output-to-string
+      (lambda ()
+        (let lp ((start 0))
+          (cond
+           ((string-contains s substring start)
+            => (lambda (end)
+                 (display (substring/shared s start end))
+                 (display replacement)
+                 (lp (+ end sublen))))
+           (else
+            (display (substring/shared s start)))))))))
+