update readme

README.md

@@ -11,13 +11,19 @@ a very simple regex engine written in go.
 - [x] `.` any single character/wildcard
 - [x] `[ ]` bracket notation/ranges
 - [x] `[^ ]` bracket negation notation
-- [ ] Quantifiers
+- [x] quantifiers
   - [x] `*` none or more times
   - [x] `+` one or more times
   - [x] `?` optional
-  - [ ] `{m,n}` more than or equal to `m` and less than equal to `n` times
-- [ ] Capturing Group
+  - [x] `{m,n}` more than or equal to `m` and less than equal to `n` times
+- [x] capturing group
   - [x] `( )` capturing group or subexpression
   - [x] `\n` backreference, e.g, `(dog)\1` where `n` is in `[0, 9]`
   - [x] `\k<name>` named backreference, e.g, `(?<animal>dog)\k<animal>`
 - [ ] `\` escape character
+  - [ ] support special characters - context dependant
+- [ ] better error handling in the API
+- [ ] ability to work on multi-line strings
+  - [ ] `.` should not match the newline - `\n`
+  - [ ] `$` should match the newline - `\n`
+  - [ ] multiple full matches

parse.go

@@ -10,9 +10,6 @@ type regexTokenType uint8
 
 const (
 	Literal         regexTokenType = iota // any literal character, e.g., a, b, 1, 2, etc.
-	NoneOrMore                     = iota // *
-	OneOrMore                      = iota // +
-	Optional                       = iota // ?
 	Or                             = iota // |
 	Bracket                        = iota // []
 	BracketNot                     = iota // [^]
@@ -294,6 +291,7 @@ func processChar(regexString string, memory *parsingContext, ch uint8) {
 		for regexString[endPos] != '}' {
 			endPos++
 		}
+		memory.advTo(endPos)
 		expr := regexString[startPos:endPos]
 		pieces := strings.Split(expr, ",")
 
@@ -306,14 +304,12 @@ func processChar(regexString string, memory *parsingContext, ch uint8) {
 		} else if len(pieces) == 2 {
 			start, _ = strconv.Atoi(pieces[0])
 			if pieces[1] == "" {
-				end = -1 // infinity
+				end = QuantifierInfinity
 			} else {
 				end, _ = strconv.Atoi(pieces[1])
 			}
 		}
 
-		memory.advTo(endPos)
-
 		token := regexToken{
 			tokenType: Quantifier,
 			value: quantifier{