FEAT: implemented case and no-case PARSE keywords

resolves: Oldes/Rebol-issues#1898

Author: Oldes

src/boot/words.reb

@@ -156,6 +156,8 @@ while
 return
 limit
 ??
+case
+no-case
 accept
 break
 ; match words:

src/core/u-parse.c

@@ -810,6 +810,13 @@ void Print_Parse_Index(REBCNT type, REBVAL *rules, REBSER *series, REBCNT index)
 					case SYM_QQ:
 						Print_Parse_Index(parse->type, rules, series, index);
 						continue;
+
+					case SYM_CASE:
+						parse->flags |= AM_FIND_CASE;
+						continue;
+					case SYM_NO_CASE:
+						parse->flags &= ~AM_FIND_CASE;
+						continue;
 					}
 				}
 				// Any other cmd must be a match command, so proceed...

src/tests/units/parse-test.r3

@@ -122,6 +122,24 @@ Rebol [
 ===end-group===
 
 
+===start-group=== "CASE / NO-CASE"
+;@@ https://github.com/Oldes/Rebol-issues/issues/1898
+--test-- "case/no-case 1"
+	--assert parse      "aAaBbBcccDDD" [no-case "AAA" case "BbB" "ccc" no-case "ddd"]
+	--assert parse/case "aAaBbBcccDDD" [no-case "AAA" case "BbB" "ccc" no-case "ddd"]
+--test-- "case/no-case 2"
+	--assert all [parse b: ["aAa"][case ["AAA" | change "aAa" "AAA"]] b == ["AAA"]]
+	--assert all [parse b: ["aAa"][case "AAA" | no-case change "aaa" "AAA"] b == ["AAA"]]
+--test-- "case/no-case 3"
+	--assert parse "aaaAB" [case thru #"A" #"B"]
+	--assert parse "aaaAB" [case thru #"A" no-case #"b"]
+--test-- "case/no-case 4"
+	--assert     parse to binary! "aaaAB" [thru #"A" #"B"]
+	--assert     parse to binary! "aaaAB" [thru #"A" no-case #"b"]
+	--assert not parse to binary! "aaaAB" [thru #"A" #"b"]
+===end-group===
+
+
 ===start-group=== "CHANGE"
 
 --test-- "CHANGE string"