Method VisitTemporalAnnotation

parse/parse.go:786–812

VisitTemporalAnnotation visits a parse tree produced by MangleParser#temporalAnnotation. Returns an *ast.Interval.

(ctx *gen.TemporalAnnotationContext)

// VisitTemporalAnnotation visits a parse tree produced by MangleParser#temporalAnnotation.
// Returns an *ast.Interval.
func (p Parser) VisitTemporalAnnotation(ctx *gen.TemporalAnnotationContext) any {
	bounds := ctx.AllTemporalBound()
	if len(bounds) == 0 {
		p.errors.Add("temporal annotation requires at least one bound", ctx.GetStart().GetLine(), ctx.GetStart().GetColumn())
		return nil
	}

	start := p.Visit(bounds[0]).(ast.TemporalBound)

	var end ast.TemporalBound
	if len(bounds) > 1 {
		end = p.Visit(bounds[1]).(ast.TemporalBound)
	} else {
		// Point interval: @[t] means @[t, t]
		end = start
	}

	if start.Type == ast.VariableBound && start.Variable.Symbol == "_" {
		start = ast.NegativeInfinity()
	}
	if end.Type == ast.VariableBound && end.Variable.Symbol == "_" {
		end = ast.PositiveInfinity()
	}

	interval := ast.NewInterval(start, end)
	return &interval
}

// VisitTemporalBound visits a parse tree produced by MangleParser#temporalBound.
// Returns an ast.TemporalBound.