added continue keyword

Author: RednibCoding

README.md

@@ -539,14 +539,26 @@ while x < 5 {
 ```
 
 ### Break
-In order to break out of a loop early, you can use the break keyword
+In order to break out of a loop early, you can use the `break` keyword
 ```js
 while true {
     println("I am not an endless loop")
     break
 }
 ```
 
+### Continue
+In order to stop the current iteration of a loop and skip right to the loop condition, you can use the `continue` keyword
+```js
+a = 10
+while a > 0 {
+    a = a -1
+    if a % 2 == 0 then continue
+    println(a)
+}
+```
+
+
 ## Data Types
 
 ### Number

ast.go

@@ -3,25 +3,26 @@ package runevm
 type ExprType string
 
 const (
-	Num    ExprType = "num"
-	Str    ExprType = "str"
-	Bool   ExprType = "bool"
-	Var    ExprType = "var"
-	Assign ExprType = "assign"
-	Binary ExprType = "binary"
-	Unary  ExprType = "unary"
-	Fun    ExprType = "fun"
-	If     ExprType = "if"
-	Block  ExprType = "block"
-	Call   ExprType = "call"
-	Return ExprType = "return"
-	While  ExprType = "while"
-	Break  ExprType = "break"
-	Array  ExprType = "array"
-	Table  ExprType = "table"
-	Pair   ExprType = "pair"
-	Index  ExprType = "Index"
-	Import ExprType = "import"
+	Num      ExprType = "num"
+	Str      ExprType = "str"
+	Bool     ExprType = "bool"
+	Var      ExprType = "var"
+	Assign   ExprType = "assign"
+	Binary   ExprType = "binary"
+	Unary    ExprType = "unary"
+	Fun      ExprType = "fun"
+	If       ExprType = "if"
+	Block    ExprType = "block"
+	Call     ExprType = "call"
+	Return   ExprType = "return"
+	While    ExprType = "while"
+	Break    ExprType = "break"
+	Continue ExprType = "continue"
+	Array    ExprType = "array"
+	Table    ExprType = "table"
+	Pair     ExprType = "pair"
+	Index    ExprType = "Index"
+	Import   ExprType = "import"
 )
 
 type Expr struct {

editor/vscode/rune/rune-1.0.0.vsix

@@ -14,9 +14,6 @@
 	  {
 		"include": "#numbers"
 	  },
-	  {
-		"include": "#functions"
-	  },
 	  {
 		"include": "#user-defined-functions"
 	  },
@@ -41,11 +38,11 @@
 		"patterns": [
 		  {
 			"name": "keyword.control.rune",
-			"match": "\\b(import|if|then|elif|else|while|break|return)\\b"
+			"match": "\\b(import|if|then|elif|else|while|break|continue|return)\\b"
 		  },
 		  {
 			"name": "constant.language.rune",
-			"match": "\\b(fun|true|false|not|array|table)\\b"
+			"match": "\\b(true|false|not|array|table|fun)\\b"
 		  }
 		]
 	  },
@@ -72,22 +69,15 @@
 		  }
 		]
 	  },
-	  "functions": {
-		"patterns": [
-		  {
-			"name": "entity.name.function.rune",
-			"match": "\\b(fun)\\s+([a-zA-Z_][a-zA-Z0-9_]*)\\b"
-		  }
-		]
-	  },
+	
 	  "user-defined-functions": {
 		"patterns": [
 		  {
 			"name": "entity.name.function.user-defined.rune",
 			"begin": "\\b([a-zA-Z_][a-zA-Z0-9_]*)\\b\\s*=\\s*\\b(fun)\\b",
 			"beginCaptures": {
 			  "1": { "name": "entity.name.function.rune" },
-			  "2": { "name": "keyword.control.rune" }
+			  "2": { "name": "constant.language.rune" }
 			},
 			"end": "(?={|;)",
 			"patterns": [

editor/vscode/rune/syntaxes/rune.tmLanguage.json

@@ -25,6 +25,10 @@ type BreakValue struct {
 	Value bool
 }
 
+type ContinueValue struct {
+	Value bool
+}
+
 func (e *Evaluator) evaluate(exp *Expr, env *Environment) interface{} {
 	if exp == nil {
 		Error(exp, "Null expression error, this is a bug and should never happen!. Please file a bug!")
@@ -160,12 +164,20 @@ func (e *Evaluator) evaluate(exp *Expr, env *Environment) interface{} {
 			if !cond.(bool) {
 				break
 			}
+			shouldContinue := false
 			for _, exp := range exp.Body.Block {
 				result := e.evaluate(exp, env)
 				if _, ok := result.(BreakValue); ok {
 					return false
+				} else if _, ok := result.(ContinueValue); ok {
+					shouldContinue = true
+					break
 				}
 			}
+			if shouldContinue {
+				shouldContinue = false
+				continue
+			}
 		}
 		return false
 
@@ -229,6 +241,9 @@ func (e *Evaluator) evaluate(exp *Expr, env *Environment) interface{} {
 	case Break:
 		return BreakValue{Value: false}
 
+	case Continue:
+		return ContinueValue{Value: false}
+
 	case Import:
 		path := e.evaluate(exp.Left, env).(string) + ".rune"
 		if _, alreadyImported := e.importedPaths[path]; alreadyImported {

evaluator.go

@@ -1,18 +1,22 @@
 
-a = 1
+a = 10
 
 while true {
-    if a <= 0 then break
     a = a -1
+    if a <= 0 then break
+    if a % 2 == 0 then continue
     println(a)
 }
 
+println("Loop finished")
+
 main = fun() {
     println("Hello, World!")
     return = 42
     println("After return")
 
 }
+
 val = main()
 println(val)
 

example/test.rune

@@ -436,6 +436,18 @@ func (p *Parser) parseBreakExpr() *Expr {
 	}
 }
 
+func (p *Parser) parseContinueExpr() *Expr {
+	tok := p.input.Peek()
+	p.skipKw("continue")
+	return &Expr{
+		Type:  Continue,
+		Right: FALSE,
+		File:  tok.File,
+		Line:  tok.Line,
+		Col:   tok.Col,
+	}
+}
+
 func (p *Parser) parseAtom() *Expr {
 	var expr *Expr
 	if p.isPunc("(") != nil {
@@ -465,6 +477,8 @@ func (p *Parser) parseAtom() *Expr {
 		expr = p.parseReturnExpr()
 	} else if p.isKw("break") != nil {
 		expr = p.parseBreakExpr()
+	} else if p.isKw("continue") != nil {
+		expr = p.parseContinueExpr()
 
 	} else {
 		tok := p.input.Next()

parser.go

@@ -24,7 +24,7 @@ type TokenStream struct {
 
 func NewTokenStream(input *InputStream) *TokenStream {
 	keywords := map[string]bool{
-		"if": true, "then": true, "elif": true, "else": true, "while": true, "break": true, "fun": true, "return": true,
+		"if": true, "then": true, "elif": true, "else": true, "while": true, "break": true, "continue": true, "fun": true, "return": true,
 		"true": true, "false": true, "array": true, "table": true, "import": true, "not": true,
 	}
 	return &TokenStream{input: input, keywords: keywords}