func (this *InitialProject) processTerms(item value.AnnotatedValue, context *Context) bool {
n := len(this.plan.Terms())
var f map[string]interface{}
if item.Type() == value.OBJECT {
f = item.Copy().Fields()
}
if f == nil {
f = make(map[string]interface{}, n)
}
pv := value.NewAnnotatedValue(f)
pv.SetAttachments(item.Attachments())
p := value.NewValue(make(map[string]interface{}, n+32))
pv.SetAttachment("projection", p)
for _, term := range this.plan.Terms() {
if term.Result().Alias() != "" {
v, err := term.Result().Expression().Evaluate(item, context)
if err != nil {
context.Error(errors.NewError(err, "Error evaluating projection."))
return false
}
p.SetField(term.Result().Alias(), v)
// Explicit aliases override data
if term.Result().As() != "" {
pv.SetField(term.Result().As(), v)
}
} else {
// Star
starval := item.GetValue()
if term.Result().Expression() != nil {
var err error
starval, err = term.Result().Expression().Evaluate(item, context)
if err != nil {
context.Error(errors.NewError(err, "Error evaluating projection."))
return false
}
}
// Latest star overwrites previous star
switch sa := starval.Actual().(type) {
case map[string]interface{}:
for k, v := range sa {
p.SetField(k, v)
}
}
}
}
return this.sendItem(pv)
}
func (this *Unnest) processItem(item value.AnnotatedValue, context *Context) bool {
ev, err := this.plan.Term().Expression().Evaluate(item, context)
if err != nil {
context.Error(errors.NewError(err, "Error evaluating UNNEST path."))
return false
}
actuals := ev.Actual()
switch actuals.(type) {
case []interface{}:
case nil:
actuals = []interface{}(nil)
default:
actuals = []interface{}{actuals}
}
acts := actuals.([]interface{})
if len(acts) == 0 {
// Outer unnest
return !this.plan.Term().Outer() || this.sendItem(item)
}
// Attach and send
for i, act := range acts {
var av value.AnnotatedValue
if i < len(acts)-1 {
av = value.NewAnnotatedValue(item.Copy())
} else {
av = item
}
av.SetField(this.plan.Alias(), value.NewValue(act))
if !this.sendItem(av) {
return false
}
}
return true
}
func (this *Join) processItem(item value.AnnotatedValue, context *Context) bool {
kv, e := this.plan.Term().Keys().Evaluate(item, context)
if e != nil {
context.Error(errors.NewError(e, "Error evaluating JOIN keys."))
return false
}
actuals := kv.Actual()
switch actuals.(type) {
case []interface{}:
case nil:
actuals = []interface{}(nil)
default:
actuals = []interface{}{actuals}
}
acts := actuals.([]interface{})
if len(acts) == 0 {
// Outer join
return !this.plan.Outer() || this.sendItem(item)
}
// Build list of keys
keys := make([]string, 0, len(acts))
for _, key := range acts {
k := value.NewValue(key).Actual()
switch k := k.(type) {
case string:
keys = append(keys, k)
}
}
// Fetch
pairs, err := this.plan.Keyspace().Fetch(keys)
if err != nil {
context.Error(err)
return false
}
found := len(pairs) > 0
// Attach and send
for i, pair := range pairs {
joinItem := pair.Value
var jv value.AnnotatedValue
// Apply projection, if any
projection := this.plan.Term().Projection()
if projection != nil {
projectedItem, e := projection.Evaluate(joinItem, context)
if e != nil {
context.Error(errors.NewError(e,
"Error evaluating join path."))
return false
}
jv = value.NewAnnotatedValue(projectedItem)
} else {
jv = value.NewAnnotatedValue(joinItem)
}
jv.SetAttachment("meta", map[string]interface{}{"id": keys[i]})
var av value.AnnotatedValue
if i < len(pairs)-1 {
av = value.NewAnnotatedValue(item.Copy())
} else {
av = item
}
av.SetField(this.plan.Term().Alias(), jv)
if !this.sendItem(av) {
return false
}
}
return found || !this.plan.Outer() || this.sendItem(item)
}