patch: doc, extract schema, cleaner bindnode use

traversal/patch/eval.go

@@ -1,3 +1,10 @@
+// Package patch provides an implementation of the IPLD Patch specification.
+// IPLD Patch is a system for declaratively specifying patches to a document,
+// which can then be applied to produce a new, modified document.
+//
+//
+// This package is EXPERIMENTAL; its behavior and API might change as it's still
+// in development.
 package patch
 
 import (

traversal/patch/parse.go

@@ -1,64 +1,25 @@
 package patch
 
 import (
+	_ "embed"
+
 	"bytes"
 	"io"
 
 	"github.com/ipld/go-ipld-prime"
 	"github.com/ipld/go-ipld-prime/codec"
 	"github.com/ipld/go-ipld-prime/node/bindnode"
+	"github.com/ipld/go-ipld-prime/schema"
 
 	"github.com/ipld/go-ipld-prime/codec/json"
 	"github.com/ipld/go-ipld-prime/datamodel"
-	"github.com/ipld/go-ipld-prime/schema"
 )
 
-var ts = func() *schema.TypeSystem {
-	ts, err := ipld.LoadSchemaBytes(
-		// This could be more accurately modelled as an inline union,
-		// but that seems like work, given how high the overlap is.
-		//
-		// This schema may also belong in the specs repo,
-		// but if so, we'd still replicate it here,
-		// because as a rule, we don't require the specs repo submodule be present for the source to compile (just for all the tests to run).
-		[]byte(`
-		# Op represents the kind of operation to perfrom
-		# The current set is based on the JSON Patch specification
-		# We may end up adding more operations in the future
-		type Op enum {
-			| add
-			| remove
-			| replace
-			| move
-			| copy
-			| test
-		}
+//go:embed patch.ipldsch
+var embedSchema []byte
 
-		# Operation and OperationSequence are the types that describe operations (but not what to apply them on).
-		# See the Instruction type for describing both operations and what to apply them on.
-		type Operation struct {
-			op Op
-			path String
-			value optional Any
-			from optional String
-		}
-		type OperationSequence [Operation]
-
-		type Instruction struct {
-			startAt Link
-			operations OperationSequence
-			# future: optional field for adl signalling and/or other lenses
-		}
-		type InstructionResult union {
-			| Error "error"
-			| Link "result"
-		} representation keyed
-		type Error struct {
-			code String # enum forthcoming
-			message String
-			details {String:String}
-		}
-	`))
+var ts = func() *schema.TypeSystem {
+	ts, err := ipld.LoadSchemaBytes(embedSchema)
 	if err != nil {
 		panic(err)
 	}
@@ -80,11 +41,9 @@ func Parse(r io.Reader, dec codec.Decoder) ([]Operation, error) {
 	for _, opRaw := range *opsRaw {
 		// TODO check the Op string
 		op := Operation{
-			Op:   Op(opRaw.Op),
-			Path: datamodel.ParsePath(opRaw.Path),
-		}
-		if opRaw.Value != nil {
-			op.Value = *opRaw.Value
+			Op:    Op(opRaw.Op),
+			Path:  datamodel.ParsePath(opRaw.Path),
+			Value: opRaw.Value,
 		}
 		if opRaw.From != nil {
 			op.From = datamodel.ParsePath(*opRaw.From)
@@ -99,6 +58,6 @@ func Parse(r io.Reader, dec codec.Decoder) ([]Operation, error) {
 type operationRaw struct {
 	Op    string
 	Path  string
-	Value *datamodel.Node
+	Value datamodel.Node
 	From  *string
 }

traversal/patch/patch.ipldsch

@@ -0,0 +1,39 @@
+# Op represents the kind of operation to perfrom
+# The current set is based on the JSON Patch specification
+# We may end up adding more operations in the future
+type Op enum {
+  | add
+  | remove
+  | replace
+  | move
+  | copy
+  | test
+}
+
+# Operation and OperationSequence are the types that describe operations (but not what to apply them on).
+# See the Instruction type for describing both operations and what to apply them on.
+type Operation struct {
+  op Op
+  path String
+  value optional Any
+  from optional String
+}
+
+type OperationSequence [Operation]
+
+type Instruction struct {
+  startAt Link
+  operations OperationSequence
+  # future: optional field for adl signalling and/or other lenses
+}
+
+type InstructionResult union {
+  | Error "error"
+  | Link "result"
+} representation keyed
+
+type Error struct {
+  code String # enum forthcoming
+  message String
+  details {String:String}
+}