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ferret/pkg/runtime/expressions/data_source.go
Tim Voronov 34c8c02258
Refactoring/externalized html (#234)
* Externalized HTML drivers

* Fixed unit tests

* Updated logging

* Added support to set default driver

* Updated GetIn and SetIn helpers
2019-02-19 18:10:18 -05:00

78 lines
1.8 KiB
Go

package expressions
import (
"context"
"github.com/MontFerret/ferret/pkg/runtime/collections"
"github.com/MontFerret/ferret/pkg/runtime/core"
"github.com/MontFerret/ferret/pkg/runtime/values/types"
)
type DataSource struct {
src core.SourceMap
valVariable string
keyVariable string
exp core.Expression
}
func NewDataSource(
src core.SourceMap,
valVariable,
keyVariable string,
exp core.Expression,
) (collections.Iterable, error) {
if exp == nil {
return nil, core.Error(core.ErrMissedArgument, "expression")
}
return &DataSource{
src,
valVariable,
keyVariable,
exp,
}, nil
}
func (ds *DataSource) Iterate(ctx context.Context, scope *core.Scope) (collections.Iterator, error) {
select {
case <-ctx.Done():
return nil, core.ErrTerminated
default:
data, err := ds.exp.Exec(ctx, scope)
if err != nil {
return nil, core.SourceError(ds.src, err)
}
switch data.Type() {
case types.Array:
return collections.NewIndexedIterator(ds.valVariable, ds.keyVariable, data.(collections.IndexedCollection))
case types.Object:
return collections.NewKeyedIterator(ds.valVariable, ds.keyVariable, data.(collections.KeyedCollection))
default:
// fallback to user defined types
switch collection := data.(type) {
case core.Iterable:
iterator, err := collection.Iterate(ctx)
if err != nil {
return nil, err
}
return collections.NewCoreIterator(ds.valVariable, ds.keyVariable, iterator)
case collections.KeyedCollection:
return collections.NewKeyedIterator(ds.valVariable, ds.keyVariable, collection)
case collections.IndexedCollection:
return collections.NewIndexedIterator(ds.valVariable, ds.keyVariable, collection)
default:
return nil, core.TypeError(
data.Type(),
types.Array,
types.Object,
core.NewType("Iterable"),
)
}
}
}
}