feat(string): add string:ascii?

Author: SuperFola

String.ark

@@ -106,6 +106,11 @@
 # @author https://github.com/SuperFola
 (let setAt (fun (_str _index _x) (builtin__string:setAt _str _index _x)))
 
+# @brief Check if a string is only ASCII
+# @param _str String where the lookup occurs
+# @author https://github.com/SuperFola
+(let ascii? (fun (_str) (= (len _str) (builtin__string:utf8len _str))))
+
 # @brief Check if a string contains a word
 # @param _str String where the lookup occurs
 # @param _word Word to look up for

tests/string-tests.ark

@@ -12,6 +12,13 @@
     (test:eq (builtin__string:removeAt "abcd" -1) "abc")
     (test:eq (builtin__string:setAt "abcd" 1 "z") (string:setAt "abcd" 1 "z")) })
 
+  (test:case "ascii?" {
+    (test:expect (string:ascii? ""))
+    (test:expect (string:ascii? string:asciiLetters))
+    (test:expect (string:ascii? string:whitespace))
+    (test:expect (not (string:ascii? "abcdé")))
+    (test:expect (not (string:ascii? "🏳️‍⚧️"))) })
+
   (test:case "contains?" {
     (test:expect (string:contains? "hello, world" "h"))
     (test:expect (string:contains? "hello, world" "hello"))