Use bash command when assigning valuables

src/std/text.ab

@@ -8,23 +8,26 @@ fun bash_version(): Num {
 
 /// Replaces all occurrences of a pattern in the content with the provided replace text.
 pub fun replace(source, search, replace) {
-    search = trust $ echo \$\{{nameof search}//\\\\/\\\\\\\\} $
+    // Here we use commands for assigning values to avoid the side effect of Amber
+    // Escape `\` as `\\`.
+    trust $ {nameof search}="\$\{{nameof search}//\\\\/\\\\\\\}" $
     if bash_version() >= 502 {
-        replace = trust $ echo \$\{{nameof replace}//\\\\/\\\\\\\\} $
+        trust $ {nameof replace}="\$\{{nameof replace}//\\\\/\\\\\\\\}" $
     } else {
-        replace = trust $ echo \$\{{nameof replace}//\\\\/\\\\} $
+        trust $ {nameof replace}="\$\{{nameof replace}//\\\\/\\\\}" $
     }
-    return trust $ echo \$\{{nameof source}//{search}/{replace}} $
+    return trust $ echo "\$\{{nameof source}//{search}/{replace}}" $
 }
 
 /// Replaces the first occurrence of a pattern in the content with the provided replace text.
 pub fun replace_once(source, search, replace) {
-    search = replace(search, "\\", "\\\\")
+    // Here we use commands for assigning values to avoid the side effect of Amber
+    trust $ {nameof search}="\$\{{nameof search}//\\\\/\\\\\\\}" $
     if bash_version() >= 502 {
-        replace = replace(replace, "\\", "\\\\")
+        trust $ {nameof replace}="\$\{{nameof replace}//\\\\/\\\\\\\\}" $
     }
 
-    return trust $ echo \$\{{nameof source}/{search}/{replace}} $
+    return trust $ echo "\$\{{nameof source}/{search}/{replace}}" $
 }
 
 /// Replaces all occurrences of a regex pattern in the content with the provided replace text.

src/tests/stdlib/replace.ab

@@ -4,8 +4,13 @@ import * from "std/text"
 // TWO TWO TWO
 // a\\b\\c\\d
 // first..second..third..fourth
+// mono
+// di
+// tri
 main {
     echo replace("one one one", "one", "TWO")
     echo replace("a\\b\\c\\d", "\\", "\\\\")
     echo replace("first\nsecond\nthird\nfourth", "\n", "..")
+    // other newlines should not be touched
+    echo replace("mono\ndo\ntri", "do\n", "di\n")
 }

src/tests/stdlib/replace_once.ab

@@ -6,9 +6,14 @@ import * from "std/text"
 // first..second
 // third
 // fourth
+// mono
+// di
+// tri
 
 main {
     echo replace_once("one one one", "one", "TWO")
     echo replace_once("a\\b\\c\\d", "\\", "\\\\")
     echo replace_once("first\nsecond\nthird\nfourth", "\n", "..")
+    // other newlines should not be touched
+    echo replace_once("mono\ndo\ntri", "do\n", "di\n")
 }