Allow tailing comma in arguments (expr-lang#623)

* feat: extract code for compiling equal operator

* feat: support last argument append with comma

---------

Co-authored-by: Anton Medvedev <[email protected]>

Author: 2 people

parser/parser.go

@@ -549,6 +549,10 @@ func (p *parser) parseCall(token Token, arguments []Node, checkOverrides bool) N
 			arguments = append(arguments, node)
 		}
 
+		// skip last comma
+		if p.current.Is(Operator, ",") {
+			p.next()
+		}
 		p.expect(Bracket, ")")
 
 		node = p.createNode(&BuiltinNode{
@@ -593,6 +597,9 @@ func (p *parser) parseArguments(arguments []Node) []Node {
 		if len(arguments) > offset {
 			p.expect(Operator, ",")
 		}
+		if p.current.Is(Bracket, ")") {
+			break
+		}
 		node := p.parseExpression(0)
 		arguments = append(arguments, node)
 	}

parser/parser_test.go

@@ -839,6 +839,42 @@ world`},
 				Expr: &IdentifierNode{Value: "x"},
 			},
 		},
+		{
+			`all(
+				[
+				  true,
+				  false,
+				],
+				#,
+			)`,
+			&BuiltinNode{
+				Name: "all",
+				Arguments: []Node{
+					&ArrayNode{
+						Nodes: []Node{
+							&BoolNode{Value: true},
+							&BoolNode{Value: false},
+						},
+					},
+					&PredicateNode{
+						Node: &PointerNode{},
+					},
+				},
+			},
+		},
+		{
+			`func(
+				parameter1,
+				parameter2,
+			)`,
+			&CallNode{
+				Callee: &IdentifierNode{Value: "func"},
+				Arguments: []Node{
+					&IdentifierNode{Value: "parameter1"},
+					&IdentifierNode{Value: "parameter2"},
+				},
+			},
+		},
 	}
 	for _, test := range tests {
 		t.Run(test.input, func(t *testing.T) {