From 23d2d07b1a6cbbc7c96f1926e226316302596e6a Mon Sep 17 00:00:00 2001
From: Nikolay Puzanov <np@embddr.com>
Date: Wed, 30 Nov 2022 10:58:30 +0300
Subject: [PATCH] Add Racket-like string-replace function

---
 embddr/common.scm | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/embddr/common.scm b/embddr/common.scm
index e469478..47d3dff 100644
--- a/embddr/common.scm
+++ b/embddr/common.scm
@@ -16,6 +16,7 @@
           string-c-radix->number
           has-duplicates? find-duplicates
           insert-between
+          string-replace-text
 
           make-mux-selectors))
  (else
@@ -174,3 +175,18 @@
       lst
       (cons* (car lst) x
              (insert-between (cdr lst) x))))
+
+;;; Racket-like string-replace
+(define* (string-replace-text str from to #:key (all #t))
+  (let ((flen (string-length from))
+        (tlen (string-length to)))
+    (let replace ((str str) (idx 0))
+      (if (>= idx (string-length str))
+          str
+          (let ((occ (string-contains str from idx)))
+            (if occ
+                (let ((str (string-replace str to occ (+ occ flen))))
+                  (if all
+                      (replace str (+ occ tlen 1))
+                      str))
+                str))))))