Method DropCast

core/casts/collection.go:468–501

DropCast drops an existing cast.

(ctx context.Context, castIDs ...id.Cast)

// DropCast drops an existing cast.
func (pgc *Collection) DropCast(ctx context.Context, castIDs ...id.Cast) error {
	if len(castIDs) == 0 {
		return nil
	}
	// Check that each name exists before performing any deletions
	for _, castID := range castIDs {
		if _, ok := builtInCasts[castID]; ok {
			return errors.Errorf(`cannot delete built-in cast from type %s to type %s`,
				castID.SourceType().TypeName(), castID.TargetType().TypeName())
		}
		if ok, err := pgc.underlyingMap.Has(ctx, string(castID)); err != nil {
			return err
		} else if !ok {
			return errors.Errorf(`cast from type %s to type %s does not exist`,
				castID.SourceType().TypeName(), castID.TargetType().TypeName())
		}
	}

	// Now we'll remove the casts from the map
	mapEditor := pgc.underlyingMap.Editor()
	for _, castID := range castIDs {
		err := mapEditor.Delete(ctx, string(castID))
		if err != nil {
			return err
		}
	}
	newMap, err := mapEditor.Flush(ctx)
	if err != nil {
		return err
	}
	pgc.underlyingMap = newMap
	pgc.mapHash = pgc.underlyingMap.HashOf()
	return nil
}

// resolveName returns the fully resolved name of the given cast. Returns an error if the name is ambiguous.
func (pgc *Collection) resolveName(ctx context.Context, schemaName string, formattedName string) (id.Cast, error) {