implement LT_EQ and GT_EQ (#48)

Flipez · Jan 16, 2022 · b655395 · b655395 · vercel · Jan 16, 2022
1 parent 91199d8
commit b655395
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Showing 7 changed files with 48 additions and 5 deletions.
diff --git a/evaluator/evaluator_test.go b/evaluator/evaluator_test.go
@@ -1,11 +1,12 @@
 package evaluator
 
 import (
+	"testing"
+
 	"github.com/flipez/rocket-lang/lexer"
 	"github.com/flipez/rocket-lang/object"
 	"github.com/flipez/rocket-lang/parser"
 	"github.com/flipez/rocket-lang/utilities"
-	"testing"
 )
 
 func TestEvalIntegerExpression(t *testing.T) {
@@ -47,6 +48,12 @@ func TestEvalBooleanExpression(t *testing.T) {
 		{"1 > 2", false},
 		{"1 < 1", false},
 		{"1 > 1", false},
+		{"1 <= 2", true},
+		{"2 <= 2", true},
+		{"3 <= 2", false},
+		{"2 >= 1", true},
+		{"2 >= 2", true},
+		{"2 >= 3", false},
 		{"1 == 1", true},
 		{"1 != 1", false},
 		{"1 == 2", false},

diff --git a/evaluator/infix.go b/evaluator/infix.go
@@ -22,8 +22,12 @@ func evalIntegerInfix(operator string, left, right object.Object) object.Object
 		return &object.Integer{Value: leftVal / rightVal}
 	case "<":
 		return nativeBoolToBooleanObject(leftVal < rightVal)
+	case "<=":
+		return nativeBoolToBooleanObject(leftVal <= rightVal)
 	case ">":
 		return nativeBoolToBooleanObject(leftVal > rightVal)
+	case ">=":
+		return nativeBoolToBooleanObject(leftVal >= rightVal)
 	default:
 		return newError("unknown operator: %s %s %s", left.Type(), operator, right.Type())
 	}
@@ -47,8 +51,12 @@ func evalFloatInfix(operator string, left, right object.Object) object.Object {
 		return &object.Float{Value: leftVal / rightVal}
 	case "<":
 		return nativeBoolToBooleanObject(leftVal < rightVal)
+	case "<=":
+		return nativeBoolToBooleanObject(leftVal <= rightVal)
 	case ">":
 		return nativeBoolToBooleanObject(leftVal > rightVal)
+	case ">=":
+		return nativeBoolToBooleanObject(leftVal >= rightVal)
 	default:
 		return newError("unknown operator: %s %s %s", left.Type(), operator, right.Type())
 	}

diff --git a/lexer/lexer.go b/lexer/lexer.go
@@ -68,9 +68,21 @@ func (l *Lexer) NextToken() token.Token {
 	case '*':
 		tok = token.NewToken(token.ASTERISK, l.ch)
 	case '<':
-		tok = token.NewToken(token.LT, l.ch)
+		if l.peekChar() == '=' {
+			ch := l.ch
+			l.readChar()
+			tok = token.NewToken(token.LT_EQ, string(ch)+string(l.ch))
+		} else {
+			tok = token.NewToken(token.LT, l.ch)
+		}
 	case '>':
-		tok = token.NewToken(token.GT, l.ch)
+		if l.peekChar() == '=' {
+			ch := l.ch
+			l.readChar()
+			tok = token.NewToken(token.GT_EQ, string(ch)+string(l.ch))
+		} else {
+			tok = token.NewToken(token.GT, l.ch)
+		}
 	case ';':
 		tok = token.NewToken(token.SEMICOLON, l.ch)
 	case ',':

diff --git a/lexer/lexer_test.go b/lexer/lexer_test.go
@@ -30,6 +30,8 @@ func TestNextToken(t *testing.T) {
 	"foo bar"
 	[1, 2];
 	{"foo": "bar"}
+
+	5 <= 10 >= 5;
 	`
 
 	tests := []struct {
@@ -118,6 +120,12 @@ func TestNextToken(t *testing.T) {
 		{token.COLON, ":"},
 		{token.STRING, "bar"},
 		{token.RBRACE, "}"},
+		{token.INT, "5"},
+		{token.LT_EQ, "<="},
+		{token.INT, "10"},
+		{token.GT_EQ, ">="},
+		{token.INT, "5"},
+		{token.SEMICOLON, ";"},
 		{token.EOF, ""},
 	}
 

diff --git a/parser/parser.go b/parser/parser.go
@@ -26,7 +26,9 @@ var precedences = map[token.TokenType]int{
 	token.EQ:       EQUALS,
 	token.NOT_EQ:   EQUALS,
 	token.LT:       LESSGREATER,
+	token.LT_EQ:    LESSGREATER,
 	token.GT:       LESSGREATER,
+	token.GT_EQ:    LESSGREATER,
 	token.PLUS:     SUM,
 	token.MINUS:    SUM,
 	token.SLASH:    PRODUCT,
@@ -89,7 +91,9 @@ func New(l *lexer.Lexer, imports map[string]struct{}) *Parser {
 	p.registerInfix(token.NOT_EQ, p.parseInfix)
 	p.registerInfix(token.PERIOD, p.parseMethodCall)
 	p.registerInfix(token.LT, p.parseInfix)
+	p.registerInfix(token.LT_EQ, p.parseInfix)
 	p.registerInfix(token.GT, p.parseInfix)
+	p.registerInfix(token.GT_EQ, p.parseInfix)
 	p.registerInfix(token.LPAREN, p.parseCall)
 	p.registerInfix(token.LBRACKET, p.parseIndex)
 

diff --git a/parser/parser_test.go b/parser/parser_test.go
@@ -272,6 +272,8 @@ func TestParsingInfixExpressions(t *testing.T) {
 		{"5 / 5;", 5, "/", 5},
 		{"5 > 5;", 5, ">", 5},
 		{"5 < 5;", 5, "<", 5},
+		{"5 >= 5;", 5, ">=", 5},
+		{"5 <= 5;", 5, "<=", 5},
 		{"5 == 5;", 5, "==", 5},
 		{"5 != 5;", 5, "!=", 5},
 		{"true == true", true, "==", true},

diff --git a/token/token.go b/token/token.go
@@ -27,8 +27,10 @@ const (
 	ASTERISK = "*"
 	SLASH    = "/"
 
-	LT = "<"
-	GT = ">"
+	LT    = "<"
+	LT_EQ = "<="
+	GT    = ">"
+	GT_EQ = ">="
 
 	COMMA     = ","
 	SEMICOLON = ";"