go/types: Unclear what typ param in NewTypeName is #22516
Description
https://golang.org/pkg/go/types/#NewTypeName:
func NewTypeName(pos token.Pos, pkg *Package, name string, typ Type) *TypeNameIs it the underlying type? If so, that's confusing, because the underlying type param for NewNamed is named "underlying" and this one is not.
https://golang.org/pkg/go/types/#NewNamed:
func NewNamed(obj *TypeName, underlying Type, methods []*Func) *NamedTo construct a new named type, it's confusing why you have to supply a types.Type twice, especially if the typ param of NewTypeName isn't the underlying type:
// Make a new type with name Mytypename and underlying type string for package with path mypkgpath and name mypkgname:
var myPkg = types.NewPackage("mypkgpath", "mypkgname")
var myTypeName = types.NewTypeName(token.NoPos, myPkg, "Mytypename", ??????????)
var myType = types.NewNamed(myTypeName, types.Typ[types.String], nil)What should the argument be for the typ param of the NewTypeName call above (where ?????????? is)? Why does TypeName need it?
Does this issue reproduce with the latest release (go1.9.2)?
Yes
System details
go version go1.9.1 darwin/amd64
GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/willfaught/Developer/go"
GORACE=""
GOROOT="/usr/local/Cellar/go/1.9.1/libexec"
GOTOOLDIR="/usr/local/Cellar/go/1.9.1/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/_1/ggvd2t1x7hz_185crsb36zlr0000gp/T/go-build024849979=/tmp/go-build -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOROOT/bin/go version: go version go1.9.1 darwin/amd64
GOROOT/bin/go tool compile -V: compile version go1.9.1
uname -v: Darwin Kernel Version 17.0.0: Thu Aug 24 21:48:19 PDT 2017; root:xnu-4570.1.46~2/RELEASE_X86_64
ProductName: Mac OS X
ProductVersion: 10.13
BuildVersion: 17A365
lldb --version: lldb-900.0.50.1
Swift-4.0