kythe/go/indexer/markedsource.go - platform/external/kythe - Git at Google

 /*
  * Copyright 2019 The Kythe Authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *   http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package indexer

 import (
 	"fmt"
 	"go/types"
 	"log"
 	"strings"

 	"kythe.io/kythe/go/util/schema/facts"

 	"github.com/golang/protobuf/proto"

 	cpb "kythe.io/kythe/proto/common_go_proto"
 	spb "kythe.io/kythe/proto/storage_go_proto"
 )

 // MarkedSource returns a MarkedSource message describing obj.
 // See: http://www.kythe.io/docs/schema/marked-source.html.
 func (pi *PackageInfo) MarkedSource(obj types.Object) *cpb.MarkedSource {
 	ms := &cpb.MarkedSource{
 		Child: []*cpb.MarkedSource{{
 			Kind:    cpb.MarkedSource_IDENTIFIER,
 			PreText: objectName(obj),
 		}},
 	}

 	// Include the package name as context, and for objects that hang off a
 	// named struct or interface, a label for that type.
 	//
 	// For example, given
 	//     package p
 	//     var v int                // context is "p"
 	//     type s struct { v int }  // context is "p.s"
 	//     func (v) f(x int) {}
 	//              ^ ^--------------- context is "p.v.f"
 	//              \----------------- context is "p.v"
 	//
 	// The tree structure is:
 	//
 	//                 (box)
 	//                   |
 	//         (ctx)-----+-------(id)
 	//           |                |
 	//     +----"."----+(".")    name
 	//     |           |
 	//    (id) pkg    type
 	//
 	if ctx := pi.typeContext(obj); len(ctx) != 0 {
 		ms.Child = append([]*cpb.MarkedSource{{
 			Kind:              cpb.MarkedSource_CONTEXT,
 			PostChildText:     ".",
 			AddFinalListToken: true,
 			Child:             ctx,
 		}}, ms.Child...)
 	}

 	// Handle types with "interesting" superstructure specially.
 	switch t := obj.(type) {
 	case *types.Func:
 		// For functions we include the parameters and return values, and for
 		// methods the receiver.
 		//
 		// Methods:   func (R) Name(p1, ...) (r0, ...)
 		// Functions: func Name(p0, ...) (r0, ...)
 		fn := &cpb.MarkedSource{
 			Kind:  cpb.MarkedSource_BOX,
 			Child: []*cpb.MarkedSource{{PreText: "func "}},
 		}
 		sig := t.Type().(*types.Signature)
 		firstParam := 0
 		if recv := sig.Recv(); recv != nil {
 			// Parenthesized receiver type, e.g. (R).
 			fn.Child = append(fn.Child, &cpb.MarkedSource{
 				Kind:     cpb.MarkedSource_PARAMETER,
 				PreText:  "(",
 				PostText: ") ",
 				Child: []*cpb.MarkedSource{{
 					Kind:    cpb.MarkedSource_TYPE,
 					PreText: typeName(recv.Type()),
 				}},
 			})
 			firstParam = 1
 		}
 		fn.Child = append(fn.Child, ms)

 		// If there are no parameters, the lookup will not produce anything.
 		// Ensure when this happens we still get parentheses for notational
 		// purposes.
 		if sig.Params().Len() == 0 {
 			fn.Child = append(fn.Child, &cpb.MarkedSource{
 				Kind:    cpb.MarkedSource_PARAMETER,
 				PreText: "()",
 			})
 		} else {
 			fn.Child = append(fn.Child, &cpb.MarkedSource{
 				Kind:          cpb.MarkedSource_PARAMETER_LOOKUP_BY_PARAM,
 				PreText:       "(",
 				PostChildText: ", ",
 				PostText:      ")",
 				LookupIndex:   uint32(firstParam),
 			})
 		}
 		if res := sig.Results(); res != nil && res.Len() > 0 {
 			rms := &cpb.MarkedSource{Kind: cpb.MarkedSource_TYPE, PreText: " "}
 			if res.Len() > 1 {
 				// If there is more than one result type, parenthesize.
 				rms.PreText = " ("
 				rms.PostText = ")"
 				rms.PostChildText = ", "
 			}
 			for i := 0; i < res.Len(); i++ {
 				rms.Child = append(rms.Child, &cpb.MarkedSource{
 					PreText: objectName(res.At(i)),
 				})
 			}
 			fn.Child = append(fn.Child, rms)
 		}
 		ms = fn

 	case *types.Var:
 		// For variables and fields, include the type.
 		repl := &cpb.MarkedSource{
 			Kind:          cpb.MarkedSource_BOX,
 			PostChildText: " ",
 			Child: []*cpb.MarkedSource{
 				ms,
 				{Kind: cpb.MarkedSource_LOOKUP_BY_TYPED},
 			},
 		}
 		ms = repl

 	case *types.TypeName:
 		// For named types, include the underlying type.
 		repl := &cpb.MarkedSource{
 			Kind:          cpb.MarkedSource_BOX,
 			PostChildText: " ",
 			Child: []*cpb.MarkedSource{
 				{PreText: "type"},
 				ms,
 				{Kind: cpb.MarkedSource_TYPE, PreText: typeName(t.Type().Underlying())},
 			},
 		}
 		ms = repl

 	default:
 		// TODO(fromberger): Handle other variations from go/types.
 	}
 	return ms
 }

 // objectName returns a human-readable name for obj if one can be inferred.  If
 // the object has its own non-blank name, that is used; otherwise if the object
 // is of a named type, that type's name is used. Otherwise the result is "_".
 func objectName(obj types.Object) string {
 	if name := obj.Name(); name != "" {
 		return name // the object's given name
 	} else if name := typeName(obj.Type()); name != "" {
 		return name // the object's type's name
 	}
 	return "_" // not sure what to call it
 }

 // typeName returns a human readable name for typ.
 func typeName(typ types.Type) string {
 	switch t := typ.(type) {
 	case *types.Named:
 		return t.Obj().Name()
 	case *types.Basic:
 		return t.Name()
 	case *types.Struct:
 		return "struct {...}"
 	case *types.Interface:
 		return "interface {...}"
 	case *types.Pointer:
 		return "*" + typeName(t.Elem())
 	}
 	return typ.String()
 }

 // typeContext returns the package, type, and function context identifiers that
 // qualify the name of obj, if any are applicable. The result is empty if there
 // are no appropriate qualifiers.
 func (pi *PackageInfo) typeContext(obj types.Object) []*cpb.MarkedSource {
 	var ms []*cpb.MarkedSource
 	addID := func(s string) {
 		ms = append(ms, &cpb.MarkedSource{
 			Kind:    cpb.MarkedSource_IDENTIFIER,
 			PreText: s,
 		})
 	}
 	for cur := pi.owner[obj]; cur != nil; cur = pi.owner[cur] {
 		if t, ok := cur.(interface {
 			Name() string
 		}); ok {
 			addID(t.Name())
 		} else {
 			addID(typeName(cur.Type()))
 		}
 	}
 	if pkg := obj.Pkg(); pkg != nil {
 		addID(pi.importPath(pkg))
 	}
 	for i, j := 0, len(ms)-1; i < j; {
 		ms[i], ms[j] = ms[j], ms[i]
 		i++
 		j--
 	}
 	return ms
 }

 // emitCode emits a code fact for the specified marked source message on the
 // target, or logs a diagnostic.
 func (e *emitter) emitCode(target *spb.VName, ms *cpb.MarkedSource) {
 	if ms != nil {
 		bits, err := proto.Marshal(ms)
 		if err != nil {
 			log.Printf("ERROR: Unable to marshal marked source: %v", err)
 			return
 		}
 		e.writeFact(target, facts.Code, string(bits))
 	}
 }

 func (e *emitter) emitPackageMarkedSource(pi *PackageInfo) {
 	if !e.opts.emitMarkedSource() || len(pi.Files) == 0 {
 		return
 	}

 	ipath := pi.ImportPath
 	ms := &cpb.MarkedSource{
 		Child: []*cpb.MarkedSource{{
 			Kind:    cpb.MarkedSource_IDENTIFIER,
 			PreText: ipath,
 		}},
 	}
 	if p := strings.LastIndex(ipath, "/"); p > 0 {
 		ms.Child[0].PreText = ipath[p+1:]
 		ms.Child = append([]*cpb.MarkedSource{{
 			Kind: cpb.MarkedSource_CONTEXT,
 			Child: []*cpb.MarkedSource{{
 				Kind:    cpb.MarkedSource_IDENTIFIER,
 				PreText: ipath[:p],
 			}},
 			PostChildText: "/",
 		}}, ms.Child...)
 	}
 	e.emitCode(pi.VName, ms)
 }

 func (e *emitter) emitBuiltinMarkedSource(b *spb.VName) {
 	if e.opts.emitMarkedSource() {
 		e.emitCode(b, &cpb.MarkedSource{
 			Kind:    cpb.MarkedSource_TYPE,
 			PreText: strings.TrimSuffix(b.Signature, "#builtin"),
 		})
 	}
 }

 var (
 	sliceTAppMS = &cpb.MarkedSource{
 		Kind: cpb.MarkedSource_TYPE,
 		Child: []*cpb.MarkedSource{{
 			Kind:        cpb.MarkedSource_LOOKUP_BY_PARAM,
 			LookupIndex: 1,
 		}},
 		PreText: "[]",
 	}
 	pointerTAppMS = &cpb.MarkedSource{
 		Kind: cpb.MarkedSource_TYPE,
 		Child: []*cpb.MarkedSource{{
 			Kind:        cpb.MarkedSource_LOOKUP_BY_PARAM,
 			LookupIndex: 1,
 		}},
 		PreText: "*",
 	}
 	mapTAppMS = &cpb.MarkedSource{
 		Kind:    cpb.MarkedSource_TYPE,
 		PreText: "map",
 		Child: []*cpb.MarkedSource{{
 			Kind:     cpb.MarkedSource_BOX,
 			PreText:  "[",
 			PostText: "]",
 			Child: []*cpb.MarkedSource{{
 				Kind:        cpb.MarkedSource_LOOKUP_BY_PARAM,
 				LookupIndex: 1,
 			}},
 		}, {
 			Kind:        cpb.MarkedSource_LOOKUP_BY_PARAM,
 			LookupIndex: 2,
 		}},
 	}
 	tupleTAppMS = &cpb.MarkedSource{
 		Kind: cpb.MarkedSource_TYPE,
 		Child: []*cpb.MarkedSource{{
 			Kind:          cpb.MarkedSource_PARAMETER_LOOKUP_BY_PARAM,
 			LookupIndex:   1,
 			PostChildText: ", ",
 		}},
 		PreText:  "(",
 		PostText: ")",
 	}
 	variadicTAppMS = &cpb.MarkedSource{
 		Kind: cpb.MarkedSource_TYPE,
 		Child: []*cpb.MarkedSource{{
 			Kind:        cpb.MarkedSource_LOOKUP_BY_PARAM,
 			LookupIndex: 1,
 		}},
 		PreText: "...",
 	}
 	chanOmniTAppMS = &cpb.MarkedSource{
 		Kind: cpb.MarkedSource_TYPE,
 		Child: []*cpb.MarkedSource{{
 			Kind:        cpb.MarkedSource_LOOKUP_BY_PARAM,
 			LookupIndex: 1,
 		}},
 		PreText: "chan ",
 	}
 	chanSendTAppMS = &cpb.MarkedSource{
 		Kind: cpb.MarkedSource_TYPE,
 		Child: []*cpb.MarkedSource{{
 			Kind:        cpb.MarkedSource_LOOKUP_BY_PARAM,
 			LookupIndex: 1,
 		}},
 		PreText: "chan<- ",
 	}
 	chanRecvTAppMS = &cpb.MarkedSource{
 		Kind: cpb.MarkedSource_TYPE,
 		Child: []*cpb.MarkedSource{{
 			Kind:        cpb.MarkedSource_LOOKUP_BY_PARAM,
 			LookupIndex: 1,
 		}},
 		PreText: "<-chan ",
 	}
 )

 func arrayTAppMS(length int64) *cpb.MarkedSource {
 	return &cpb.MarkedSource{
 		Kind: cpb.MarkedSource_TYPE,
 		Child: []*cpb.MarkedSource{{
 			Kind:        cpb.MarkedSource_LOOKUP_BY_PARAM,
 			LookupIndex: 1,
 		}},
 		PreText: fmt.Sprintf("[%d]", length),
 	}
 }

 func chanTAppMS(dir types.ChanDir) *cpb.MarkedSource {
 	switch dir {
 	case types.SendOnly:
 		return chanSendTAppMS
 	case types.RecvOnly:
 		return chanRecvTAppMS
 	default:
 		return chanOmniTAppMS
 	}
 }
	/*
	* Copyright 2019 The Kythe Authors. All rights reserved.
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package indexer

	import (
	"fmt"
	"go/types"
	"log"
	"strings"

	"kythe.io/kythe/go/util/schema/facts"

	"github.com/golang/protobuf/proto"

	cpb "kythe.io/kythe/proto/common_go_proto"
	spb "kythe.io/kythe/proto/storage_go_proto"
	)

	// MarkedSource returns a MarkedSource message describing obj.
	// See: http://www.kythe.io/docs/schema/marked-source.html.
	func (pi PackageInfo) MarkedSource(obj types.Object) cpb.MarkedSource {
	ms := &cpb.MarkedSource{
	Child: []*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_IDENTIFIER,
	PreText: objectName(obj),
	}},
	}

	// Include the package name as context, and for objects that hang off a
	// named struct or interface, a label for that type.
	//
	// For example, given
	// package p
	// var v int // context is "p"
	// type s struct { v int } // context is "p.s"
	// func (v) f(x int) {}
	// ^ ^--------------- context is "p.v.f"
	// \----------------- context is "p.v"
	//
	// The tree structure is:
	//
	// (box)
	// \|
	// (ctx)-----+-------(id)
	// \| \|
	// +----"."----+(".") name
	// \| \|
	// (id) pkg type
	//
	if ctx := pi.typeContext(obj); len(ctx) != 0 {
	ms.Child = append([]*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_CONTEXT,
	PostChildText: ".",
	AddFinalListToken: true,
	Child: ctx,
	}}, ms.Child...)
	}

	// Handle types with "interesting" superstructure specially.
	switch t := obj.(type) {
	case *types.Func:
	// For functions we include the parameters and return values, and for
	// methods the receiver.
	//
	// Methods: func (R) Name(p1, ...) (r0, ...)
	// Functions: func Name(p0, ...) (r0, ...)
	fn := &cpb.MarkedSource{
	Kind: cpb.MarkedSource_BOX,
	Child: []*cpb.MarkedSource{{PreText: "func "}},
	}
	sig := t.Type().(*types.Signature)
	firstParam := 0
	if recv := sig.Recv(); recv != nil {
	// Parenthesized receiver type, e.g. (R).
	fn.Child = append(fn.Child, &cpb.MarkedSource{
	Kind: cpb.MarkedSource_PARAMETER,
	PreText: "(",
	PostText: ") ",
	Child: []*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_TYPE,
	PreText: typeName(recv.Type()),
	}},
	})
	firstParam = 1
	}
	fn.Child = append(fn.Child, ms)

	// If there are no parameters, the lookup will not produce anything.
	// Ensure when this happens we still get parentheses for notational
	// purposes.
	if sig.Params().Len() == 0 {
	fn.Child = append(fn.Child, &cpb.MarkedSource{
	Kind: cpb.MarkedSource_PARAMETER,
	PreText: "()",
	})
	} else {
	fn.Child = append(fn.Child, &cpb.MarkedSource{
	Kind: cpb.MarkedSource_PARAMETER_LOOKUP_BY_PARAM,
	PreText: "(",
	PostChildText: ", ",
	PostText: ")",
	LookupIndex: uint32(firstParam),
	})
	}
	if res := sig.Results(); res != nil && res.Len() > 0 {
	rms := &cpb.MarkedSource{Kind: cpb.MarkedSource_TYPE, PreText: " "}
	if res.Len() > 1 {
	// If there is more than one result type, parenthesize.
	rms.PreText = " ("
	rms.PostText = ")"
	rms.PostChildText = ", "
	}
	for i := 0; i < res.Len(); i++ {
	rms.Child = append(rms.Child, &cpb.MarkedSource{
	PreText: objectName(res.At(i)),
	})
	}
	fn.Child = append(fn.Child, rms)
	}
	ms = fn

	case *types.Var:
	// For variables and fields, include the type.
	repl := &cpb.MarkedSource{
	Kind: cpb.MarkedSource_BOX,
	PostChildText: " ",
	Child: []*cpb.MarkedSource{
	ms,
	{Kind: cpb.MarkedSource_LOOKUP_BY_TYPED},
	},
	}
	ms = repl

	case *types.TypeName:
	// For named types, include the underlying type.
	repl := &cpb.MarkedSource{
	Kind: cpb.MarkedSource_BOX,
	PostChildText: " ",
	Child: []*cpb.MarkedSource{
	{PreText: "type"},
	ms,
	{Kind: cpb.MarkedSource_TYPE, PreText: typeName(t.Type().Underlying())},
	},
	}
	ms = repl

	default:
	// TODO(fromberger): Handle other variations from go/types.
	}
	return ms
	}

	// objectName returns a human-readable name for obj if one can be inferred. If
	// the object has its own non-blank name, that is used; otherwise if the object
	// is of a named type, that type's name is used. Otherwise the result is "_".
	func objectName(obj types.Object) string {
	if name := obj.Name(); name != "" {
	return name // the object's given name
	} else if name := typeName(obj.Type()); name != "" {
	return name // the object's type's name
	}
	return "_" // not sure what to call it
	}

	// typeName returns a human readable name for typ.
	func typeName(typ types.Type) string {
	switch t := typ.(type) {
	case *types.Named:
	return t.Obj().Name()
	case *types.Basic:
	return t.Name()
	case *types.Struct:
	return "struct {...}"
	case *types.Interface:
	return "interface {...}"
	case *types.Pointer:
	return "*" + typeName(t.Elem())
	}
	return typ.String()
	}

	// typeContext returns the package, type, and function context identifiers that
	// qualify the name of obj, if any are applicable. The result is empty if there
	// are no appropriate qualifiers.
	func (pi PackageInfo) typeContext(obj types.Object) []cpb.MarkedSource {
	var ms []*cpb.MarkedSource
	addID := func(s string) {
	ms = append(ms, &cpb.MarkedSource{
	Kind: cpb.MarkedSource_IDENTIFIER,
	PreText: s,
	})
	}
	for cur := pi.owner[obj]; cur != nil; cur = pi.owner[cur] {
	if t, ok := cur.(interface {
	Name() string
	}); ok {
	addID(t.Name())
	} else {
	addID(typeName(cur.Type()))
	}
	}
	if pkg := obj.Pkg(); pkg != nil {
	addID(pi.importPath(pkg))
	}
	for i, j := 0, len(ms)-1; i < j; {
	ms[i], ms[j] = ms[j], ms[i]
	i++
	j--
	}
	return ms
	}

	// emitCode emits a code fact for the specified marked source message on the
	// target, or logs a diagnostic.
	func (e emitter) emitCode(target spb.VName, ms *cpb.MarkedSource) {
	if ms != nil {
	bits, err := proto.Marshal(ms)
	if err != nil {
	log.Printf("ERROR: Unable to marshal marked source: %v", err)
	return
	}
	e.writeFact(target, facts.Code, string(bits))
	}
	}

	func (e emitter) emitPackageMarkedSource(pi PackageInfo) {
	if !e.opts.emitMarkedSource() \|\| len(pi.Files) == 0 {
	return
	}

	ipath := pi.ImportPath
	ms := &cpb.MarkedSource{
	Child: []*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_IDENTIFIER,
	PreText: ipath,
	}},
	}
	if p := strings.LastIndex(ipath, "/"); p > 0 {
	ms.Child[0].PreText = ipath[p+1:]
	ms.Child = append([]*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_CONTEXT,
	Child: []*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_IDENTIFIER,
	PreText: ipath[:p],
	}},
	PostChildText: "/",
	}}, ms.Child...)
	}
	e.emitCode(pi.VName, ms)
	}

	func (e emitter) emitBuiltinMarkedSource(b spb.VName) {
	if e.opts.emitMarkedSource() {
	e.emitCode(b, &cpb.MarkedSource{
	Kind: cpb.MarkedSource_TYPE,
	PreText: strings.TrimSuffix(b.Signature, "#builtin"),
	})
	}
	}

	var (
	sliceTAppMS = &cpb.MarkedSource{
	Kind: cpb.MarkedSource_TYPE,
	Child: []*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_LOOKUP_BY_PARAM,
	LookupIndex: 1,
	}},
	PreText: "[]",
	}
	pointerTAppMS = &cpb.MarkedSource{
	Kind: cpb.MarkedSource_TYPE,
	Child: []*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_LOOKUP_BY_PARAM,
	LookupIndex: 1,
	}},
	PreText: "*",
	}
	mapTAppMS = &cpb.MarkedSource{
	Kind: cpb.MarkedSource_TYPE,
	PreText: "map",
	Child: []*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_BOX,
	PreText: "[",
	PostText: "]",
	Child: []*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_LOOKUP_BY_PARAM,
	LookupIndex: 1,
	}},
	}, {
	Kind: cpb.MarkedSource_LOOKUP_BY_PARAM,
	LookupIndex: 2,
	}},
	}
	tupleTAppMS = &cpb.MarkedSource{
	Kind: cpb.MarkedSource_TYPE,
	Child: []*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_PARAMETER_LOOKUP_BY_PARAM,
	LookupIndex: 1,
	PostChildText: ", ",
	}},
	PreText: "(",
	PostText: ")",
	}
	variadicTAppMS = &cpb.MarkedSource{
	Kind: cpb.MarkedSource_TYPE,
	Child: []*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_LOOKUP_BY_PARAM,
	LookupIndex: 1,
	}},
	PreText: "...",
	}
	chanOmniTAppMS = &cpb.MarkedSource{
	Kind: cpb.MarkedSource_TYPE,
	Child: []*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_LOOKUP_BY_PARAM,
	LookupIndex: 1,
	}},
	PreText: "chan ",
	}
	chanSendTAppMS = &cpb.MarkedSource{
	Kind: cpb.MarkedSource_TYPE,
	Child: []*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_LOOKUP_BY_PARAM,
	LookupIndex: 1,
	}},
	PreText: "chan<- ",
	}
	chanRecvTAppMS = &cpb.MarkedSource{
	Kind: cpb.MarkedSource_TYPE,
	Child: []*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_LOOKUP_BY_PARAM,
	LookupIndex: 1,
	}},
	PreText: "<-chan ",
	}
	)

	func arrayTAppMS(length int64) *cpb.MarkedSource {
	return &cpb.MarkedSource{
	Kind: cpb.MarkedSource_TYPE,
	Child: []*cpb.MarkedSource{{
	Kind: cpb.MarkedSource_LOOKUP_BY_PARAM,
	LookupIndex: 1,
	}},
	PreText: fmt.Sprintf("[%d]", length),
	}
	}

	func chanTAppMS(dir types.ChanDir) *cpb.MarkedSource {
	switch dir {
	case types.SendOnly:
	return chanSendTAppMS
	case types.RecvOnly:
	return chanRecvTAppMS
	default:
	return chanOmniTAppMS
	}
	}