Add 'while' loop statement to ZSS

Syntax example:

let i = 0;
map(domino) := 0;

while  < 2 {
	let i =  + 1;
	while map(domino) < (5 * ) {
		map(domino) := map(domino) + 1;
	}
}

While accepts any conditional expression, meaning, it can create infinite loops. In that case, Ikemen GO will freeze.

src/bytecode.go

@@ -2075,13 +2075,16 @@ func (cf callFunction) Run(c *Char, _ []int32) (changeState bool) {
 }
 
 type StateBlock struct {
+	// Basic block fields
 	persistent          int32
 	persistentIndex     int32
 	ignorehitpause      int32
 	ctrlsIgnorehitpause bool
 	trigger             BytecodeExp
 	elseBlock           *StateBlock
 	ctrls               []StateController
+	// Loop fields
+	loopBlock           bool
 }
 
 func newStateBlock() *StateBlock {
@@ -2107,22 +2110,42 @@ func (b StateBlock) Run(c *Char, ps []int32) (changeState bool) {
 		}
 	}
 	sys.workingChar = c
-	if len(b.trigger) > 0 && !b.trigger.evalB(c) {
-		if b.elseBlock != nil {
-			return b.elseBlock.Run(c, ps)
+	if b.loopBlock {
+		for {
+			if len(b.trigger) > 0 && !b.trigger.evalB(c) {
+				break
+			}
+			for _, sc := range b.ctrls {
+				switch sc.(type) {
+				case StateBlock:
+				default:
+					if !b.ctrlsIgnorehitpause && c.hitPause() {
+						continue
+					}
+				}
+				if sc.Run(c, ps) {
+					return true
+				}
+			}
 		}
-		return false
-	}
-	for _, sc := range b.ctrls {
-		switch sc.(type) {
-		case StateBlock:
-		default:
-			if !b.ctrlsIgnorehitpause && c.hitPause() {
-				continue
+	} else {
+		if len(b.trigger) > 0 && !b.trigger.evalB(c) {
+			if b.elseBlock != nil {
+				return b.elseBlock.Run(c, ps)
 			}
+			return false
 		}
-		if sc.Run(c, ps) {
-			return true
+		for _, sc := range b.ctrls {
+			switch sc.(type) {
+			case StateBlock:
+			default:
+				if !b.ctrlsIgnorehitpause && c.hitPause() {
+					continue
+				}
+			}
+			if sc.Run(c, ps) {
+				return true
+			}
 		}
 	}
 	if b.persistentIndex >= 0 {

src/compiler.go

@@ -4522,6 +4522,10 @@ func (c *Compiler) subBlock(line *string, root bool,
 		if err := c.switchBlock(line, bl, sbc, numVars); err != nil {
 			return nil, err
 		}
+	case "while":
+		if err := c.loopBlock(line, bl, sbc, numVars); err != nil {
+			return nil, err
+		}
 	default:
 		return nil, c.yokisinaiToken()
 	}
@@ -4663,6 +4667,27 @@ func (c *Compiler) switchBlock(line *string, bl *StateBlock,
 	}
 	return nil
 }
+func (c *Compiler) loopBlock(line *string, bl *StateBlock,
+	sbc *StateBytecode, numVars *int32) error {
+	bl.loopBlock = true
+	switch c.token {
+	// case "for": // TODO: make for loop
+	case "while":
+		expr, _, err := c.readSentence(line)
+		if err != nil {
+			return err
+		}
+		otk := c.token
+		if bl.trigger, err = c.fullExpression(&expr, VT_Bool); err != nil {
+			return err
+		}
+		c.token = otk
+		if err := c.needToken("{"); err != nil {
+			return err
+		}
+	}
+	return nil
+}
 func (c *Compiler) callFunc(line *string, root bool,
 	ctrls *[]StateController, ret []uint8) error {
 	var cf callFunction
@@ -4757,7 +4782,7 @@ func (c *Compiler) stateBlock(line *string, bl *StateBlock, root bool,
 				return c.yokisinaiToken()
 			}
 			return nil
-		case "if", "ignorehitpause", "persistent", "switch":
+		case "if", "ignorehitpause", "persistent", "switch", "while":
 			if sbl, err := c.subBlock(line, root, sbc, numVars,
 				bl != nil && bl.ctrlsIgnorehitpause); err != nil {
 				return err