chore: add deprecation warnings when casting string/bytes to regex

modules/internal/ChapelBase.chpl

@@ -1444,7 +1444,10 @@ module ChapelBase {
       // string to a type. Otherwise, we can't resolve chpl_debug_writeln in
       // `range.these`
       { var dummyRange = 1..0; for i in dummyRange {} }
-      return str:t;
+      if t:string == "regex(string)" || t:string == "regex(bytes)" then
+        return compile(str);
+      else
+        return str:t;
     }
   }
   // param s is used for error reporting

modules/standard/Regex.chpl

@@ -1142,12 +1142,14 @@ inline operator :(x: regex(bytes), type t: bytes) {
 
 // Cast string to regex
 pragma "no doc"
+deprecated "Casting strings to regex is deprecated. Use regex.compile(string) instead."
 inline operator :(x: string, type t: regex(string)) throws {
   return compile(x);
 }
 
 // Cast bytes to regex
 pragma "no doc"
+deprecated "Casting bytes to regex is deprecated. Use regex.compile(bytes) instead."
 inline operator :(x: bytes, type t: regex(bytes)) throws {
   return compile(x);
 }

test/deprecated/regexTertiary.good

@@ -1,3 +1,5 @@
+regexTertiary.chpl:8: warning: Casting strings to regex is deprecated. Use regex.compile(string) instead.
+regexTertiary.chpl:9: warning: Casting bytes to regex is deprecated. Use regex.compile(bytes) instead.
 regexTertiary.chpl:11: warning: string.search is deprecated, use regex search instead
 regexTertiary.chpl:12: warning: bytes.search is deprecated, use regex search instead
 regexTertiary.chpl:14: warning: string.search is deprecated, use regex search instead

test/regex/bytes/cast.chpl

@@ -13,3 +13,13 @@ writeln(b"contains regular expression".find(rb));
 
 writeln("doesn't contain regular expression".find(rs));
 writeln(b"doesn't contain regular expression".find(rb));
+
+
+var rcs = compile(s);
+var rcb = compile(b);
+
+writeln("contains regular expression".find(rcs));
+writeln(b"contains regular expression".find(rcb));
+
+writeln("doesn't contain regular expression".find(rcs));
+writeln(b"doesn't contain regular expression".find(rcb));

test/regex/bytes/cast.good

@@ -1,3 +1,9 @@
+cast.chpl:8: warning: Casting strings to regex is deprecated. Use regex.compile(string) instead.
+cast.chpl:9: warning: Casting bytes to regex is deprecated. Use regex.compile(bytes) instead.
+0
+0
+-1
+-1
 0
 0
 -1