fix(parser): add missing comparison operators (#369)

internal/parser/grammar.md

@@ -88,7 +88,7 @@ For the parser, the above grammar undergoes a process to have the left-recursion
     LogicalOperator = and | or .
     ComparisonExpression = MultiplicativeExpression { ComparisonExpressionSuffix } .
     ComparisonExpressionSuffix = ComparisonOperator MultiplicativeExpr .
-    ComparisonOperator = eq | neq | regexeq | regexneq .
+    ComparisonOperator = eq | neq | lt | lte | gt | gte | regexeq | regexneq .
     MultiplicativeExpression = AdditiveExpression { MultiplicativeOperator AdditiveExpression } .
     MultiplicativeOperator = mul | div .
     AdditiveExpression = PipeExpression { AdditiveExpressionSuffix } .

internal/parser/parser.go

@@ -382,6 +382,18 @@ func (p *parser) parseComparisonOperator() (ast.OperatorKind, bool) {
 	case token.NEQ:
 		p.consume()
 		return ast.NotEqualOperator, true
+	case token.LTE:
+		p.consume()
+		return ast.LessThanEqualOperator, true
+	case token.LT:
+		p.consume()
+		return ast.LessThanOperator, true
+	case token.GTE:
+		p.consume()
+		return ast.GreaterThanEqualOperator, true
+	case token.GT:
+		p.consume()
+		return ast.GreaterThanOperator, true
 	case token.REGEXEQ:
 		p.consume()
 		return ast.RegexpMatchOperator, true

internal/parser/parser_test.go

@@ -985,6 +985,57 @@ func testParser(runFn func(name string, fn func(t testing.TB))) {
 				},
 			},
 		},
+		{
+			name: "binary expression",
+			raw:  `_value < 10.0`,
+			want: &ast.Program{
+				BaseNode: base("1:1", "1:14"),
+				Body: []ast.Statement{&ast.ExpressionStatement{
+					BaseNode: base("1:1", "1:14"),
+					Expression: &ast.BinaryExpression{
+						BaseNode: base("1:1", "1:14"),
+						Operator: ast.LessThanOperator,
+						Left: &ast.Identifier{
+							BaseNode: base("1:1", "1:7"),
+							Name:     "_value",
+						},
+						Right: &ast.FloatLiteral{
+							BaseNode: base("1:10", "1:14"),
+							Value:    10.0,
+						},
+					},
+				}},
+			},
+		},
+		{
+			name: "member expression binary expression",
+			raw:  `r._value < 10.0`,
+			want: &ast.Program{
+				BaseNode: base("1:1", "1:16"),
+				Body: []ast.Statement{&ast.ExpressionStatement{
+					BaseNode: base("1:1", "1:16"),
+					Expression: &ast.BinaryExpression{
+						BaseNode: base("1:1", "1:16"),
+						Operator: ast.LessThanOperator,
+						Left: &ast.MemberExpression{
+							BaseNode: base("1:1", "1:9"),
+							Object: &ast.Identifier{
+								BaseNode: base("1:1", "1:2"),
+								Name:     "r",
+							},
+							Property: &ast.Identifier{
+								BaseNode: base("1:3", "1:9"),
+								Name:     "_value",
+							},
+						},
+						Right: &ast.FloatLiteral{
+							BaseNode: base("1:12", "1:16"),
+							Value:    10.0,
+						},
+					},
+				}},
+			},
+		},
 		{
 			name: "var as binary expression of other vars",
 			raw: `a = 1