Rich-data serialization

Pcore's rich-data protocol renders any value as a tree of data-only values (nil, bool, int64, float64, string, []Value and string-keyed Hash) in which non-data values are encoded as tagged hashes carrying a __ptype key.

d, _ := pcore.ToData(pcore.NewBinary([]byte("hi")))
// { "__ptype" => "Binary", "__pvalue" => "aGk=" }

v, _ := pcore.FromData(d) // *pcore.Binary{ "hi" }

ToData and FromData are inverse: any value round-trips, except that Sensitive is redacted by design — it serializes to { "__ptype" => "Sensitive" } with no payload and reconstructs wrapping Undef.

Encoding

Value	Rich-data form
undef	nil
bool / int64 / float64 / string	itself
Array	array of encoded elements
string-keyed Hash	a plain hash of encoded values
non-string-keyed (or reserved-key) Hash	{ __ptype: "Hash", __pvalue: [k,v,…] }
Default	{ __ptype: "Default" }
Regexp	{ __ptype: "Regexp", __pvalue: "<source>" }
Binary	{ __ptype: "Binary", __pvalue: "<base64>" }
Timestamp	{ __ptype: "Timestamp", __pvalue: "<RFC 3339>" }
Timespan	{ __ptype: "Timespan", __pvalue: "<duration>" }
Type value	{ __ptype: "Type", __pvalue: "<type string>" }
Sensitive	{ __ptype: "Sensitive" } (redacted)

A plain hash that happens to contain a __ptype / __pvalue key is encoded via the tagged Hash array form so it survives the round-trip unambiguously.

Staged for v0.2

The Timespan string form uses Go's duration syntax and round-trips within this library; the Pcore-exact Timespan textual form is staged.