Add AutoIndex

service/datastore/index.go

Index: service/datastore/index.go
diff --git a/service/datastore/index.go b/service/datastore/index.go
index d06bd9067f2a9f06991ca6559c3a4745896c7f15..9b7aef02e98a438d921a702768514ed1982dd085 100644
--- a/service/datastore/index.go
+++ b/service/datastore/index.go
@@ -228,6 +228,48 @@ func (id *IndexDefinition) Compound() bool {
 	return true
 }
 
+// YAMLString returns the YAML representation of this IndexDefinition.
+//
+// If the index definition is Builtin() or not Compound(), this will return
+// an error.
+func (id *IndexDefinition) YAMLString() (string, error) {
+	if id.Builtin() || !id.Compound() {
+		return "", fmt.Errorf("cannot generate YAML for this IndexDefinition")
+	}
+
+	ret := &bytes.Buffer{}

[Vadim Sh., 2015/09/24 19:17:29]

nit: just bytes.Buffer{}, no need for dynamic allocation

[iannucci, 2015/09/24 19:52:34]

Common misconception: there's no actual difference. The compiler reserves the
right to allocate any 'stack' allocations on the heap, or vice versa.

https://golang.org/doc/faq#stack_or_heap

[Vadim Sh., 2015/09/24 19:57:50]

"""In the current compilers, if a variable has its address taken, that variable
is a candidate for allocation on the heap. However, a basic escape analysis
recognizes some cases when such variables will not live past the return from the
function and can reside on the stack."""

I try to help escape analysis whenever I can :)

Anyhow, in this particular case "&" is just unnecessary symbol. But I don't care
much.

[iannucci, 2015/09/24 20:12:59]

it made more sense before I had the ws function. there were
fmt.Fprintf(&ret,...) everywhere.

+	indent := 0
+
+	first := true
+	ws := func(s string) {
+		nl := "\n"
+		if first {
+			nl = ""
+			first = false
+		}
+		_, err := fmt.Fprintf(ret, "%s%s%s", nl, strings.Repeat("  ", indent), s)
+		if err != nil {

[Vadim Sh., 2015/09/24 19:17:29]

just remove errcheck from pre-commit-go.yml >_< Checking Fprintf errors is
clearly paranoia.

[iannucci, 2015/09/24 19:52:34]

lol ok

+			panic(err)
+		}
+	}
+
+	ws(fmt.Sprintf("- kind: %s", id.Kind))
+	indent++
+	if id.Ancestor {
+		ws("ancestor: yes")
+	}
+	ws("properties:")
+	for _, o := range id.SortBy {
+		ws(fmt.Sprintf("- name: %s", o.Property))
+		if o.Descending {
+			indent++

[Vadim Sh., 2015/09/24 19:17:29]

:) just pass indent explicitly, e.g.

ws("properties:", 1)
...
ws("direction: desc", 2)

[iannucci, 2015/09/24 19:52:35]

done :)

+			ws("direction: desc")
+			indent--
+		}
+	}
+	return ret.String(), nil
+}
+
 func (id *IndexDefinition) String() string {
 	ret := &bytes.Buffer{}
 	wr := func(r rune) {