String Interpolation Support

implementation from hscript-iris (by inky03)

Note: it needs optimization

hscript/Bytes.hx

@@ -134,6 +134,8 @@ class Bytes {
 			// TODO
 		case ECast(e, _):
 			// TODO
+		case ERegex(e, f):
+			// TODO
 		case EConst(c):
 			doEncodeConst(c);
 		case EIdent(v):

hscript/Expr.hx

@@ -34,7 +34,7 @@ typedef UInt64 = #if cpp cpp.UInt64 #else Int #end;
 enum Const {
 	CInt( v : Int );
 	CFloat( f : Float );
-	CString( s : String );
+	CString( s : String, ?i : Bool );
 }
 
 #if hscriptPos
@@ -84,6 +84,7 @@ enum Expr {
 	EClass( name:String, fields:Array<Expr>, ?extend:String, interfaces:Array<String>, ?isFinal:Bool, ?isPrivate:Bool );
 	EEnum( en:EnumDecl, ?isAbstract:Bool );
 	ECast(e:Expr, ?t:CType);
+	ERegex(e:String, flags:String);
 }
 
 @:structInit

hscript/Interp.hx

@@ -885,6 +885,8 @@ class Interp {
 				variables.set(en.name, enumThingy);
 			case ECast(e, _): // TODO
 				return expr(e);
+			case ERegex(e, f):
+				return new EReg(e, f);
 			case EConst(c):
 				switch (c) {
 					case CInt(v): return v;

hscript/Parser.hx

@@ -43,6 +43,7 @@ enum Token {
 	TDoubleDot;
 	TMeta( s : String );
 	TPrepro( s : String );
+	TRegex( e : String, f:String );
 }
 
 @:structInit
@@ -72,6 +73,11 @@ class Parser {
 	**/
 	public var allowJSON : Bool;
 
+	/**
+		activate Regular Expression parsing 
+	**/
+	public var allowRegex : Bool;
+
 	/**
 		allow types declarations
 	**/
@@ -115,6 +121,8 @@ class Parser {
 
 	#end
 
+	static inline var regexFlags: String = "igmsu";
+
 	public function new() {
 		line = 1;
 		opChars = "+*/-=!><&|^%~";
@@ -332,7 +340,7 @@ class Parser {
 					if( !allowJSON )
 						unexpected(tk);
 					switch( c ) {
-						case CString(s): id = s;
+						case CString(s, _): id = s;
 						default: unexpected(tk);
 					}
 				case TBrClose:
@@ -369,6 +377,11 @@ class Parser {
 				e = mk(EIdent(id));
 			return parseExprNext(e);
 		case TConst(c):
+			switch(c) {
+				case CString(s, i):
+					if(i) return parseExprNext(interpolateString(s));
+				default:
+			}
 			return parseExprNext(mk(EConst(c)));
 		case TPOpen:
 			tk = token();
@@ -513,6 +526,8 @@ class Parser {
 			var e = parseExpr();
 			isVar = false;
 			return mk(EMeta(id, args, e),p1);
+		case TRegex(e, f) if(allowRegex):
+			return mk(ERegex(e, f), p1);
 		default:
 			return unexpected(tk);
 		}
@@ -1628,6 +1643,94 @@ class Parser {
 		}
 		return args;
 	}
+	
+	// From hscript-iris: https://github.com/pisayesiwsi/hscript-iris/blob/dev/crowplexus/hscript/Parser.hx#L409
+	// by inky03
+	function interpolateString(s:String):Expr {
+		var exprs:Array<Expr> = [];
+		var dollarPos:Int = s.indexOf('$');
+
+		if(dollarPos == -1)
+			return mk(EConst(CString(s)));
+
+		final singleFirst:EReg = ~/[a-zA-Z_]/i;
+		final singleExpr:EReg = ~/[a-zA-Z0-9_]/i;
+		// TODO: optimize this using regex
+		while(dollarPos > -1) {
+			var pos:Int = dollarPos;
+			var pre:String = s.substr(0, pos);
+			var next:String = s.charAt(++pos);
+			if(next == '{') {
+				if (pre != '')
+					exprs.push(mk(EConst(CString(pre))));
+				var exprStr:String = '';
+				var depth:Int = 1;
+				while (true) {
+					next = s.charAt(++pos);
+					if (next == '{') {
+						depth++;
+					} else if (next == '}') {
+						depth--;
+					}
+					if (depth < 1)
+						break;
+					if (pos >= s.length) {
+						error(EUnterminatedString, pos, pos);
+					}
+					exprStr += next;
+				}
+				if (exprStr.trim() == '') {
+					error(ECustom("Expression cannot be empty"), pos, pos);
+				}
+				var prevChar = char;
+				var prevInput = input;
+				var prevReadPos = readPos; // a bit stupid innit???
+				#if hscriptPos
+				var prevOrigin = origin;
+				#end
+				var expr = parseString('($exprStr)' #if hscriptPos, origin #end);
+				readPos = prevReadPos; // rolling back parser state because otherwise we get problems...
+				input = prevInput;
+				char = prevChar;
+				#if hscriptPos
+				origin = prevOrigin;
+				#end
+				exprs.push(expr);
+				pos++;
+			}
+			else if(singleFirst.match(next)) {
+				if (pre != '')
+					exprs.push(mk(EConst(CString(pre))));
+				var ident: String = '';
+				while(singleExpr.match(next)) {
+					ident += next;
+					next = s.charAt(++pos);
+				}
+				exprs.push(mk(EIdent(ident)));
+			}
+			else if (next == '$') {
+				var secondToNext: String = s.charAt(pos);
+				if (secondToNext == "$") { // if its another dollar, skip...
+					s = pre + s.substr(pos, pos + 1); // remove $ ahead of the current one
+					break;
+				}
+				exprs.push(mk(EConst(CString(pre + '$'))));
+			}
+			s = s.substr(pos++);
+			dollarPos = s.indexOf('$');
+		}
+		if (exprs.length == 0) {
+			return mk(EConst(CString(s)));
+		} else {
+			exprs.push(mk(EConst(CString(s))));
+			var expr:Null<Expr> = exprs.shift();
+			while(true) {
+				if(exprs.length == 0) break;
+				expr = mk(EBinop('+', expr, exprs.shift()));
+			}
+			return expr;
+		}
+	}
 
 	function checkAccess(get:FieldPropertyAccess, set:FieldPropertyAccess, ?expr:Expr, ?type:CType) {
 		#if hscriptPos
@@ -1863,8 +1966,9 @@ class Parser {
 		return StringTools.fastCodeAt(input, readPos++);
 	}
 
-	function readString( until:Int ):String {
+	function readString( until:Int, regex:Bool = false, interpolate:Bool = false ):String {
 		var c = 0;
+		var prev = 0;
 		var b = new StringBuf();
 		var esc = false;
 		var old = line;
@@ -1911,18 +2015,93 @@ class Parser {
 					b.addChar(k);
 				default: invalidChar(c);
 				}
-			} else if( c == 92 )
+			} else if( c == 92 && !regex)
 				esc = true;
-			else if( c == until )
-				break;
+			else if( c == until ) {
+				if(regex && prev == 92) {
+					b.addChar(c);
+					prev = c;
+				}
+				else
+					break;
+			}
+			else if (c == 36 && interpolate) { // brace for impact !!
+				// From hscript-iris: https://github.com/pisayesiwsi/hscript-iris/blob/dev/crowplexus/hscript/Parser.hx#L1665
+				// by inky03
+				// TODO: optimize this
+				b.addChar(c);
+				var next = readChar();
+				if (next == 123) {
+					b.addChar(next);
+					var depth:Int = 0;
+					while (true) {
+						next = readChar();
+						if (StringTools.isEof(next)) {
+							error(EUnterminatedString, p1, p1);
+						}
+						b.addChar(next);
+						if (next == "'".code) {
+							var nextStr:String = readString("'".code, false, true);
+							for (char in nextStr) {
+								b.addChar(char);
+							}
+							b.addChar("'".code);
+							next = readChar();
+							b.addChar(next);
+						}
+						if (next == 125) {
+							depth--;
+							if (depth < 0)
+								break;
+						}
+					}
+				} else {
+					readPos--;
+				}
+			}
 			else {
 				if( c == 10 ) line++;
 				b.addChar(c);
+				if(regex)
+					prev = c;
 			}
 		}
 		return b.toString();
 	}
 
+	function readFlags():String {
+		if(!allowRegex) return null;
+		var c = 0;
+		var b = new StringBuf();
+		var old = line;
+		var s = input;
+		#if hscriptPos
+		var p1 = readPos - 1;
+		#end
+
+		while(true) {
+			var c = readChar();
+			if( StringTools.isEof(c) ) {
+				line = old;
+				error(EUnterminatedString, p1, p1);
+				break;
+			}
+			// semicolon
+			if(c == 59) {
+				this.char = c;
+				break;
+			}
+			
+			var f = String.fromCharCode(c);
+			if(regexFlags.indexOf(f) != -1) 
+				b.addChar(c);
+			else
+				invalidChar(c);
+		}
+
+		return b.toString();
+	}
+
 	function token():Token {
 	//function token(?infos : Null<haxe.PosInfos>) {
 		//function ttrace(v:Dynamic, ?infos : Null<haxe.PosInfos>) {
@@ -2090,7 +2269,10 @@ class Parser {
 			case "}".code: return TBrClose;
 			case "[".code: return TBkOpen;
 			case "]".code: return TBkClose;
-			case "'".code, '"'.code: return TConst( CString(readString(char)) );
+			case "'".code:
+				return TConst( CString(readString(char, false, true), true) );
+			case '"'.code: 
+				return TConst( CString(readString(char), false) );
 			case "?".code:
 				char = readChar();
 				switch (char) {
@@ -2146,7 +2328,7 @@ class Parser {
 				invalidChar(char);
 			default:
 				if( ops[char] ) {
-					var op = String.fromCharCode(char);
+					var op:String = String.fromCharCode(char);
 					while( true ) {
 						char = readChar();
 						if( StringTools.isEof(char) ) char = 0;
@@ -2156,6 +2338,11 @@ class Parser {
 						}
 						var pop = op;
 						op += String.fromCharCode(char);
+						if( allowRegex && op == "~/") {
+							var e = readString(char, true);
+							var f = readFlags();
+							return TRegex(e, f);
+						}
 						if( !opPriority.exists(op) && opPriority.exists(pop) ) {
 							if( op == "//" || op == "/*" )
 								return tokenComment(op,char);
@@ -2346,7 +2533,7 @@ class Parser {
 		return switch(c) {
 		case CInt(v): Std.string(v);
 		case CFloat(f): Std.string(f);
-		case CString(s): s; // TODO : escape + quote
+		case CString(s, _): s; // TODO : escape + quote
 		}
 	}
 
@@ -2370,6 +2557,7 @@ class Parser {
 		case TDoubleDot: ":";
 		case TMeta(id): "@" + id;
 		case TPrepro(id): "#" + id;
+		case TRegex(e, f): '~/$e/$f';
 		}
 	}
 

hscript/Printer.hx

@@ -186,6 +186,9 @@ class Printer {
 				addType(t);
 				add(")");
 			}
+		case ERegex(e, f):
+			add('~/$e/$f');
+			add(';\n');
 		case EConst(c):
 			switch( c ) {
 			case CInt(i): add(i);