From 4acc09faf9231770cc2dff86902e9269e6ab6410 Mon Sep 17 00:00:00 2001
From: jmug <u.g.a.mariano@gmail.com>
Date: Sun, 5 Jan 2025 11:37:13 -0800
Subject: [PATCH] Parsed grouped expressions (that was easy!).

Signed-off-by: jmug <u.g.a.mariano@gmail.com>
---
 pkg/parser/parser.go      | 11 +++++++++++
 pkg/parser/parser_test.go | 20 ++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/pkg/parser/parser.go b/pkg/parser/parser.go
index 1ba76c2..9223f43 100644
--- a/pkg/parser/parser.go
+++ b/pkg/parser/parser.go
@@ -37,6 +37,7 @@ func New(l *lexer.Lexer) *Parser {
 	p.registerPrefix(token.BANG, p.parsePrefixExpression)
 	p.registerPrefix(token.TRUE, p.parseBoolean)
 	p.registerPrefix(token.FALSE, p.parseBoolean)
+	p.registerPrefix(token.LPAREN, p.parseGroupedExpression)
 	// Infix registrations
 	p.registerInfix(token.PLUS, p.parseInfixExpression)
 	p.registerInfix(token.MINUS, p.parseInfixExpression)
@@ -176,6 +177,16 @@ func (p *Parser) parseInfixExpression(left ast.Expression) ast.Expression {
 	return exp
 }
 
+func (p *Parser) parseGroupedExpression() ast.Expression {
+	p.nextToken()
+	exp := p.parseExpression(LOWEST)
+	if !p.expectPeek(token.RPAREN) {
+		// TODO: Would probably be good to emit an error here?
+		return nil
+	}
+	return exp
+}
+
 func (p *Parser) curTokenIs(typ token.TokenType) bool {
 	return p.curToken.Type == typ
 }
diff --git a/pkg/parser/parser_test.go b/pkg/parser/parser_test.go
index b96dfbe..ca2a979 100644
--- a/pkg/parser/parser_test.go
+++ b/pkg/parser/parser_test.go
@@ -316,6 +316,26 @@ func TestOperatorPrecedenceParsing(t *testing.T) {
 			"3 < 5 == true",
 			"((3 < 5) == true)",
 		},
+		{
+			"1 + (2 + 3) + 4",
+			"((1 + (2 + 3)) + 4)",
+		},
+		{
+			"(5 + 5) * 2",
+			"((5 + 5) * 2)",
+		},
+		{
+			"2 / (5 + 5)",
+			"(2 / (5 + 5))",
+		},
+		{
+			"-(5 + 5)",
+			"(-(5 + 5))",
+		},
+		{
+			"!(true == true)",
+			"(!(true == true))",
+		},
 	}
 
 	for _, tt := range tests {