feat: Integer literals parsing; and tests

AST/ast_imp.go

@@ -97,6 +97,7 @@ type ReturnStatement struct{
 	Token token.Token // the token is "return"
 	ReturnValue Expression
 }
+
 //Node interface methods 
 func (reStm *ReturnStatement) TokenLiteral() string{  // satisfies the node interface 
 	return reStm.Token.Value
@@ -111,6 +112,7 @@ func (resStm *ReturnStatement) ToString() string {
 	bf.WriteString(";")
 	return bf.String()
 }
+
 // statements imp
 func (reStm *ReturnStatement) statementNode() { } // satisfies the statement interface
 
@@ -129,6 +131,7 @@ type ExpressionStatement struct{
 func (exStm *ExpressionStatement) TokenLiteral() string{
 	return exStm.Token.Value
 }
+
 func (exStm *ExpressionStatement) ToString() string{
 	var bf bytes.Buffer
 	if exStm.Expression !=nil {
@@ -137,4 +140,27 @@ func (exStm *ExpressionStatement) ToString() string{
 	return bf.String()
 }
 
-func (exStm *ExpressionStatement) statementNode(){}
+func (exStm *ExpressionStatement) statementNode(){}
+
+
+
+
+/*
+* Integer Literals Node
+* they can Occur in different type of expression's
+*/
+type IntegerLiteral struct {
+	Token token.Token
+	Value int // we do not specify int size to make it platform independent (32,64)
+}
+
+func (intLiteral *IntegerLiteral) TokenLiteral() string{
+	return intLiteral.Token.Value
+}
+
+func (intLiteral *IntegerLiteral) expressionNode() {}
+
+func (intLiteral *IntegerLiteral) ToString() string {
+	return intLiteral.Token.Value
+}
+

parser/parser.go

@@ -2,6 +2,7 @@ package parser
 
 import (
 	"fmt"
+	"strconv"
 
 	ast "github.com/houcine7/JIPL/AST"
 	"github.com/houcine7/JIPL/lexer"
@@ -45,6 +46,7 @@ func InitParser(l *lexer.Lexer) *Parser{
 	// init ParseFunctions maps
 	p.prefixParseFuncs = make(map[token.TokenType]prefixParse)
 	p.addPrefixFn(token.IDENTIFIER,p.parseIdentifier)
+	p.addPrefixFn(token.INT,p.parserInt)
 
 	return p;
 }
@@ -79,9 +81,9 @@ func (p *Parser) Parse() *ast.Program{
 	for !p.currentTokenEquals(token.FILE_ENDED) {
 		stm := p.parseStmt()
 		//fmt.Println(stm.TokenLiteral())
-		if stm !=nil {
-			program.Statements =append(program.Statements, stm )
-		}
+		// if stm !=nil {
+		program.Statements =append(program.Statements, stm )
+		// }
 		// Advance with token
 		p.NextToken()
 	}
@@ -175,6 +177,29 @@ func (p *Parser) parseIdentifier() ast.Expression{
 	return &ast.Identifier{Token: p.currToken,Value: p.currToken.Value}
 }
 
+func (p *Parser) parserInt() ast.Expression {
+	exp := &ast.IntegerLiteral{Token: p.currToken}
+	val,err := strconv.ParseInt(p.currToken.Value,0,0)
+
+	if err !=nil {
+		errMsg := fmt.Sprintf("Parsing error, couldn't parse string %s to Integer value",
+		p.currToken.Value)
+		p.errors = append(p.errors, errMsg)
+		return nil
+	}
+
+	exp.Value = int(val)
+
+	return exp
+}
+
+
+
+
+
+
+//Helper functions
+
 func (p *Parser) currentTokenEquals(t token.TokenType) bool{
 	return p.currToken.Type == t;
 }

parser/parser_test.go

@@ -116,6 +116,45 @@ func TestIdentifier(t *testing.T){
 	}
 }
 
+
+// Integer literals test
+func TestIntegerLiteral(t *testing.T){
+	input :="81;"
+
+	lexer := lexer.InitLexer(input)
+	parser := InitParser(lexer)
+
+	pr :=parser.Parse()
+	checkParserErrors(parser,t)
+	checkIsProgramStmLengthValid(pr,t,1)
+
+	stm,ok := pr.Statements[0].(*ast.ExpressionStatement)
+	if !ok {
+		t.Fatalf("program.statement[0] is not of type expressionStatement instead got=%T",
+	pr.Statements[0])
+	}
+
+	intLiteral,ok :=stm.Expression.(*ast.IntegerLiteral)
+	if !ok{
+		t.Fatalf("stm.Expression is not of type *ast.IntegerLiteral instead got=%T",
+	stm.Expression)
+	}
+
+	if intLiteral.Value != int(81){
+		t.Errorf("the Integer literal value is not correct, expected=%d instead got=%d",
+	81,intLiteral.Value)
+	}
+
+	if intLiteral.TokenLiteral() !="81" {
+		t.Errorf("the TokenLiteral value is not correct, expected=%s instead got=%s",
+	"81",intLiteral.TokenLiteral())
+	}
+
+}
+
+
+
+// Tests helper functions 
 func checkIsProgramStmLengthValid(program *ast.Program,t *testing.T,length int){
 	if len(program.Statements) !=length {
 		t.Fatalf("the program.Statements doesn't not contain 3 statements, instead we got %d",