Strings

lexer/lexer.go

@@ -91,6 +91,9 @@ func (l *Lexer) NextToken() token.Token {
 	case 0:
 		tok.Literal = ""
 		tok.Type = token.EOF
+	case '"':
+		tok.Type = token.STRING
+		tok.Literal = l.readString()
 	default:
 		if isLetter(l.ch) {
 			tok.Literal = l.readIdentifier()
@@ -145,3 +148,14 @@ func (l *Lexer) skipWhitespace() {
 		l.readChar()
 	}
 }
+
+func (l *Lexer) readString() string {
+	position := l.position + 1
+	for {
+		l.readChar()
+		if l.ch == '"' || l.ch == 0 {
+			break
+		}
+	}
+	return l.input[position:l.position]
+}

lexer/lexer_test.go

@@ -7,25 +7,27 @@ import (
 
 func TestNextToken(t *testing.T) {
 	input := `let five = 5;
-let ten = 10;
-
-let add = fn(x, y) {
-  x + y;
-};
-
-let result = add(five, ten);
-!-/*5;
-5 < 10 > 5;
-
-if (5 < 10) {
-    return true;
-} else {
-    return false;
-}
-
-10 == 10;
-10 != 9;
-`
+				let ten = 10;
+				
+				let add = fn(x, y) {
+				  x + y;
+				};
+				
+				let result = add(five, ten);
+				!-/*5;
+				5 < 10 > 5;
+				
+				if (5 < 10) {
+					return true;
+				} else {
+					return false;
+				}
+				
+				10 == 10;
+				10 != 9;
+				"foobar"
+				"foo bar"
+			`
 
 	tests := []struct {
 		expectedType    token.TokenType
@@ -113,6 +115,8 @@ if (5 < 10) {
 		{token.INT, "9"},
 		{token.SEMICOLON, ";"},
 
+		{token.STRING, "foobar"},
+		{token.STRING, "foo bar"},
 		{token.EOF, ""},
 	}