Fix method call, index and prefix's precedence.

compiler/bytecode/statement_generation.go

@@ -34,6 +34,10 @@ func (g *Generator) compileStatements(stmts []ast.Statement, scope *scope, table
 func (g *Generator) compileStatement(is *InstructionSet, statement ast.Statement, scope *scope, table *localTable) {
 	switch stmt := statement.(type) {
 	case *ast.ExpressionStatement:
+		if stmt.Expression == nil {
+			return
+		}
+
 		if !g.REPL && stmt.Expression.IsStmt() {
 			g.compileExpression(is, stmt.Expression, scope, table)
 			is.define(Pop, statement.Line())

compiler/parser/expression_parsing.go

@@ -163,6 +163,10 @@ func (p *Parser) parseExpression(precedence int) ast.Expression {
 
 	leftExp := parseFn()
 
+	if leftExp == nil {
+		return nil
+	}
+
 	/*
 		Precedence example:
 
@@ -194,10 +198,6 @@ func (p *Parser) parseExpression(precedence int) ast.Expression {
 		leftExp = infixFn(leftExp)
 	}
 
-	if p.peekTokenIs(token.Semicolon) {
-		p.nextToken()
-	}
-
 	return leftExp
 }
 

compiler/parser/parser.go

@@ -118,7 +118,7 @@ func (p *Parser) ParseProgram() (program *ast.Program, err *errors.Error) {
 		if recover() != nil {
 			err = p.error
 			if err == nil {
-				msg := fmt.Sprintf("Some panic happen token: %s. Line: %d", p.curToken.Literal, p.curToken.Line)
+				msg := fmt.Sprintf("Some panic happen token: %s Line: %d", p.curToken.Literal, p.curToken.Line)
 				err = errors.InitError(msg, errors.SyntaxError)
 			}
 		}

compiler/parser/precedence/precedence.go

@@ -15,9 +15,9 @@ const (
 	Sum
 	Product
 	BangPrefix
-	Index
 	Call
 	MinusPrefix
+	Index
 )
 
 // LookupTable maps token to its corresponding precedence