feat(core): add and & or infixExpression keywords

evaluator/evaluator.go

@@ -98,10 +98,8 @@ func Eval(node ast.Node, env *object.Environment) object.Object {
 			} else {
 				env.Set(ident.Value, value)
 			}
-
-			return &object.Null{}
-		}
-		return newError(node.Token.FileName, node.Token.Line, node.Token.Column, "expected identifier on left got=%T", node.Left)
+		} else {
+		return newError(node.Token.FileName, node.Token.Line, node.Token.Column, "expected identifier on left got=%T", node.Left) }
 	case *ast.BacktickLiteral:
 		return backTickOperation(node.Value)
 	case *ast.AssignStatement:
@@ -330,9 +328,9 @@ func evalInfixExpression(operator string, node ast.Expression, leftOperand, righ
 			return nativeBoolToBooleanObject(leftOperand == rightOperand)
 		case operator == "!=":
 			return nativeBoolToBooleanObject(leftOperand != rightOperand)
-		case operator == "&&":
+		case operator == "&&" || operator == "and":
 			return nativeBoolToBooleanObject(objectToNativeBoolean(leftOperand) && objectToNativeBoolean(rightOperand))
-		case operator == "-|":
+		case operator == "||" || operator == "or":
 			return nativeBoolToBooleanObject(objectToNativeBoolean(leftOperand) || objectToNativeBoolean(rightOperand))
 		case leftOperand.Type() != rightOperand.Type():
 			return newError(node.Token.FileName, node.Token.Line, node.Token.Column, "type mismatch: %s %s %s", leftOperand.Type(), operator, rightOperand.Type())

parser/parser.go

@@ -128,6 +128,8 @@ func New(L *lexer.Lexer) *Parser {
 	p.registerInfix(token.MOD, p.parseInfixExpression)
 	p.registerInfix(token.AND, p.parseInfixExpression)
 	p.registerInfix(token.OR, p.parseInfixExpression)
+	p.registerInfix(token.STRING_OR, p.parseInfixExpression)
+	p.registerInfix(token.STRING_AND, p.parseInfixExpression)
 	p.registerInfix(token.LPAREN, p.parseCallExpression)
 	p.registerInfix(token.LBRACKET, p.parseIndexExpression)
 	p.registerInfix(token.PERIOD, p.parseMethodCallExpression)
@@ -180,7 +182,7 @@ func (P *Parser) parseIfExpression() ast.Expression {
 
 	expression.Consequence = P.parseBlockStatement()
 
-	if P.peekTokenLS(token.ELSE_IF) {
+	if P.peekTokenMatches(token.ELSE_IF) {
 		P.nextToken()
 		expression.Alternative = &ast.BlockStatement{
 			Statements: []ast.Statement{
@@ -192,7 +194,7 @@ func (P *Parser) parseIfExpression() ast.Expression {
 		return expression
 	}
 
-	if P.peekTokenLS(token.ELSE) {
+	if P.peekTokenMatches(token.ELSE) {
 		P.nextToken()
 
 		if !P.expectPeek(token.LBRACE) {
@@ -213,7 +215,7 @@ parseBoolean parses a boolean expression
 func (P *Parser) parseBoolean() ast.Expression {
 	return &ast.Boolean{
 		Token: P.currentToken,
-		Value: P.currentTokenLS(token.TRUE),
+		Value: P.currentTokenMatches(token.TRUE),
 	}
 }
 
@@ -297,7 +299,7 @@ func (P *Parser) parseReturnStatement() *ast.ReturnStatement {
 	stmt := &ast.ReturnStatement{Token: P.currentToken}
 	P.nextToken()
 	stmt.ReturnValue = P.parseExpression(LOWEST)
-	if P.peekTokenLS(token.SEMICOLON) {
+	if P.peekTokenMatches(token.SEMICOLON) {
 		P.nextToken()
 	}
 	return stmt
@@ -321,7 +323,7 @@ func (P *Parser) parseLetStatement() *ast.LetStatement {
 
 	stmt.Value = P.parseExpression(LOWEST)
 
-	if P.peekTokenLS(token.SEMICOLON) {
+	if P.peekTokenMatches(token.SEMICOLON) {
 		P.nextToken()
 	}
 
@@ -330,7 +332,7 @@ func (P *Parser) parseLetStatement() *ast.LetStatement {
 
 // expectPeek checks if the next token is as expected - returns a boolean
 func (P *Parser) expectPeek(t token.TokenType) bool {
-	if P.peekTokenLS(t) {
+	if P.peekTokenMatches(t) {
 		P.nextToken()
 		return true
 	} else {
@@ -339,19 +341,19 @@ func (P *Parser) expectPeek(t token.TokenType) bool {
 	}
 }
 
-// currentTokenLS checks if the current matches the expected tokenType - returns a boolean
-func (P *Parser) currentTokenLS(t token.TokenType) bool { return P.currentToken.Type == t }
+// currentTokenMatches checks if the current token type matches the expected tokenType - returns a boolean
+func (P *Parser) currentTokenMatches(t token.TokenType) bool { return P.currentToken.Type == t }
 
-// peekTokenLS checks if the next token matches the expected tokenType - returns a boolean
-func (P *Parser) peekTokenLS(t token.TokenType) bool { return P.peekToken.Type == t }
+// peekTokenMatches checks if the next token matches the expected tokenType - returns a boolean
+func (P *Parser) peekTokenMatches(t token.TokenType) bool { return P.peekToken.Type == t }
 
 // parseExpressionStatement parses an expression statement such as 5 + 5 or x * y;
 func (P *Parser) parseExpressionStatement() *ast.ExpressionStatement {
 	// defer untrace(trace("parseExpressionStatement"))
 	stmt := &ast.ExpressionStatement{Token: P.currentToken}
 	stmt.Expression = P.parseExpression(LOWEST)
 
-	for P.peekTokenLS(token.SEMICOLON) {
+	for P.peekTokenMatches(token.SEMICOLON) {
 		P.nextToken()
 	}
 	return stmt
@@ -419,7 +421,7 @@ func (p *Parser) parseExpression(precedence int) ast.Expression {
 		return nil
 	}
 	leftExp := prefix()
-	for !p.peekTokenLS(token.SEMICOLON) && precedence < p.peekPrecedence() {
+	for !p.peekTokenMatches(token.SEMICOLON) && precedence < p.peekPrecedence() {
 		infix := p.infixParseFns[p.peekToken.Type]
 		if infix == nil {
 			return leftExp
@@ -453,7 +455,7 @@ func (P *Parser) parseBlockStatement() *ast.BlockStatement {
 
 	P.nextToken()
 
-	for !P.currentTokenLS(token.RBRACE) && !P.currentTokenLS(token.EOF) {
+	for !P.currentTokenMatches(token.RBRACE) && !P.currentTokenMatches(token.EOF) {
 		stmt := P.parseStatement()
 		if stmt != nil {
 			block.Statements = append(block.Statements, stmt)
@@ -486,7 +488,7 @@ func (P *Parser) parseFunctionLiteral() ast.Expression {
 func (P *Parser) parseFunctionParameters() []*ast.Identifier {
 	identifiers := []*ast.Identifier{}
 
-	if P.peekTokenLS(token.RPAREN) {
+	if P.peekTokenMatches(token.RPAREN) {
 		P.nextToken()
 		return identifiers
 	}
@@ -495,7 +497,7 @@ func (P *Parser) parseFunctionParameters() []*ast.Identifier {
 	ident := &ast.Identifier{Token: P.currentToken, Value: P.currentToken.Literal}
 	identifiers = append(identifiers, ident)
 
-	for P.peekTokenLS(token.COMMA) {
+	for P.peekTokenMatches(token.COMMA) {
 		P.nextToken()
 		P.nextToken()
 		ident := &ast.Identifier{
@@ -528,7 +530,7 @@ func (P *Parser) parseCallArguments() []ast.Expression {
 	args := []ast.Expression{}
 
 	// no arguments
-	if P.peekTokenLS(token.RPAREN) {
+	if P.peekTokenMatches(token.RPAREN) {
 		P.nextToken()
 		return args
 	}
@@ -538,7 +540,7 @@ func (P *Parser) parseCallArguments() []ast.Expression {
 	args = append(args, P.parseExpression(LOWEST))
 
 	// get args separated by commas
-	for P.peekTokenLS(token.COMMA) {
+	for P.peekTokenMatches(token.COMMA) {
 		P.nextToken()
 		P.nextToken()
 		args = append(args, P.parseExpression(LOWEST))
@@ -568,15 +570,15 @@ func (P *Parser) parseArrayLiteral() ast.Expression {
 func (P *Parser) parseExpressionList(end token.TokenType) []ast.Expression {
 	list := []ast.Expression{}
 
-	if P.peekTokenLS(end) {
+	if P.peekTokenMatches(end) {
 		P.nextToken()
 		return list
 	}
 
 	P.nextToken()
 	list = append(list, P.parseExpression(LOWEST))
 
-	for P.peekTokenLS(token.COMMA) {
+	for P.peekTokenMatches(token.COMMA) {
 		P.nextToken()
 		P.nextToken()
 		list = append(list, P.parseExpression(LOWEST))
@@ -625,7 +627,7 @@ func (P *Parser) parseHashLiteral() ast.Expression {
 	hash := &ast.HashLiteral{Token: P.currentToken}
 	hash.Pairs = make(map[ast.Expression]ast.Expression)
 
-	for !P.peekTokenLS(token.RBRACE) {
+	for !P.peekTokenMatches(token.RBRACE) {
 		P.nextToken()
 
 		key := P.parseExpression(LOWEST)
@@ -638,7 +640,7 @@ func (P *Parser) parseHashLiteral() ast.Expression {
 		value := P.parseExpression(LOWEST)
 
 		hash.Pairs[key] = value
-		if !P.peekTokenLS(token.RBRACE) && !P.expectPeek(token.COMMA) {
+		if !P.peekTokenMatches(token.RBRACE) && !P.expectPeek(token.COMMA) {
 			return nil
 		}
 	}
@@ -726,16 +728,16 @@ func (P *Parser) parseFunctionDefParameter() (map[string]ast.Expression, []*ast.
 	identifiers := make([]*ast.Identifier, 0)
 
 	// Is the next parameter ")" ?  If so we're done. No args.
-	if P.peekTokenLS(token.RPAREN) {
+	if P.peekTokenMatches(token.RPAREN) {
 		P.nextToken()
 		return m, identifiers
 	}
 	P.nextToken()
 
 	// Keep going until we find a ")"
-	for !P.currentTokenLS(token.RPAREN) {
+	for !P.currentTokenMatches(token.RPAREN) {
 
-		if P.currentTokenLS(token.EOF) {
+		if P.currentTokenMatches(token.EOF) {
 			P.errors = append(P.errors, "unterminated function parameters")
 			return nil, nil
 		}
@@ -747,15 +749,15 @@ func (P *Parser) parseFunctionDefParameter() (map[string]ast.Expression, []*ast.
 
 		// If there is "=xx" after the name then that's
 		// the default parameter.
-		if P.currentTokenLS(token.ASSIGN) {
+		if P.currentTokenMatches(token.ASSIGN) {
 			P.nextToken()
 			// Save the default value.
 			m[ident.Value] = P.parseExpressionStatement().Expression
 			P.nextToken()
 		}
 
 		// Skip any comma.
-		if P.currentTokenLS(token.COMMA) {
+		if P.currentTokenMatches(token.COMMA) {
 			P.nextToken()
 		}
 	}

repl/repl.go

@@ -76,7 +76,7 @@ func Start(in io.Reader, out io.Writer) {
 			}
 		} else {
 			line = strings.Trim(line, " ")
-			if line[0] == ':' {
+			if len(line) != 0 && line[0] == ':' {
 				evaluateReplCommand(line[1:])
 			} else {
 				evaluteInput("repl.eso", line, logger, environmnet)

token/token.go

@@ -62,7 +62,9 @@ const (
 	WHEN        = "WHEN"
 	MOD         = "%"
 	AND         = "&&"
-	OR          = "-|"
+	OR          = "||"
+	STRING_OR   = "OR"
+	STRING_AND  = "AND"
 	PERIOD      = "."
 	IMPORT      = "IMPORT"
 )
@@ -71,6 +73,8 @@ const (
 var keywords = map[string]TokenType{
 	"fn":     FUNCTION,
 	"let":    LET,
+	"and":    AND,
+	"or":     OR,
 	"true":   TRUE,
 	"false":  FALSE,
 	"if":     IF,