Method VisitTemporalOperator

parse/parse.go:853–896

VisitTemporalOperator visits a parse tree produced by MangleParser#temporalOperator. Returns an *ast.TemporalOperator.

(ctx *gen.TemporalOperatorContext)

// VisitTemporalOperator visits a parse tree produced by MangleParser#temporalOperator.
// Returns an *ast.TemporalOperator.
func (p Parser) VisitTemporalOperator(ctx *gen.TemporalOperatorContext) any {
	bounds := ctx.AllTemporalBound()
	if len(bounds) != 2 {
		p.errors.Add("temporal operator requires exactly two bounds", ctx.GetStart().GetLine(), ctx.GetStart().GetColumn())
		return nil
	}

	// Check for negative durations in temporal operator bounds.
	// The temporal operator determines direction (past/future), not the duration sign.
	// Negative durations are rejected to avoid confusion.
	for _, boundCtx := range bounds {
		if dur := boundCtx.(*gen.TemporalBoundContext).DURATION(); dur != nil {
			text := dur.GetText()
			if strings.HasPrefix(text, "-") {
				p.errors.Add(
					fmt.Sprintf("negative duration %q not allowed in temporal operator; use the operator type to indicate direction (e.g., <-[...] for past, <+[...] for future)", text),
					boundCtx.GetStart().GetLine(), boundCtx.GetStart().GetColumn())
			}
		}
	}

	start := p.Visit(bounds[0]).(ast.TemporalBound)
	end := p.Visit(bounds[1]).(ast.TemporalBound)
	interval := ast.NewInterval(start, end)

	var opType ast.TemporalOperatorType
	if ctx.DIAMONDMINUS() != nil {
		opType = ast.DiamondMinus
	} else if ctx.BOXMINUS() != nil {
		opType = ast.BoxMinus
	} else if ctx.DIAMONDPLUS() != nil {
		opType = ast.DiamondPlus
	} else if ctx.BOXPLUS() != nil {
		opType = ast.BoxPlus
	} else {
		p.errors.Add("unknown temporal operator", ctx.GetStart().GetLine(), ctx.GetStart().GetColumn())
		return nil
	}

	return &ast.TemporalOperator{
		Type:     opType,
		Interval: interval,
	}
}

// parseTimestamp parses a timestamp string in ISO 8601 format.
func parseTimestamp(s string) (time.Time, error) {