Add regex.escape

src/gleam/regex.gleam

@@ -3,7 +3,9 @@
 //// all of the PCRE library is interfaced and some parts of the library go beyond
 //// what PCRE offers. Currently PCRE version 8.40 (release date 2017-01-11) is used.
 
+import gleam/list
 import gleam/option.{type Option}
+import gleam/string
 
 pub type Regex
 
@@ -214,3 +216,23 @@ pub fn replace(
   in string: String,
   with substitute: String,
 ) -> String
+
+/// Escapes all `Regex` characters in a given `String`.
+///
+/// ## Examples
+///
+/// ```gleam
+/// regex.escape("hello$world^test")
+/// // -> "hello\\$world\\^test"
+/// ```
+///
+/// ```gleam
+/// regex.escape("$^.*+?()[]{}|\\")
+/// // -> "\\$\\^\\.\\*\\+\\?\\(\\)\\[\\]\\{\\}\\|\\\\"
+/// ```
+pub fn escape(input: String) -> String {
+  ["\\", "$", "^", ".", "*", "+", "?", "(", ")", "[", "]", "{", "}", "|"]
+  |> list.fold(input, fn(acc, char) {
+    string.replace(in: acc, each: char, with: "\\" <> char)
+  })
+}

test/gleam/regex_test.gleam

@@ -185,3 +185,28 @@ pub fn replace_3_test() {
   regex.replace(re, "🐈🐈 are great!", "🐕")
   |> should.equal("🐕🐕 are great!")
 }
+
+pub fn escape_test() {
+  // Test escaping common regex symbols
+  let input = "$^.*+?()[]{}|\\"
+  let expected = "\\$\\^\\.\\*\\+\\?\\(\\)\\[\\]\\{\\}\\|\\\\"
+  input
+  |> regex.escape
+  |> should.equal(expected)
+}
+
+pub fn escape_no_special_chars_test() {
+  let input = "hello"
+  let expected = "hello"
+  input
+  |> regex.escape
+  |> should.equal(expected)
+}
+
+pub fn escape_mixed_string_test() {
+  let input = "hello$world^test"
+  let expected = "hello\\$world\\^test"
+  input
+  |> regex.escape
+  |> should.equal(expected)
+}