From c3b57af8bc0fb4fe9b30e42891e9aff54c0c7a82 Mon Sep 17 00:00:00 2001 From: Robert Griesemer Date: Wed, 4 Aug 2021 21:10:31 -0700 Subject: [PATCH] [dev.typeparams] cmd/compile/internal/types2: minor cleanup of writeTParamList Change-Id: Iaa58b17ad65e93548bb3da8231e0cb6da0c48105 Reviewed-on: https://go-review.googlesource.com/c/go/+/339903 Trust: Robert Griesemer Run-TryBot: Robert Griesemer TryBot-Result: Go Bot Reviewed-by: Robert Findley --- src/cmd/compile/internal/types2/infer.go | 2 +- src/cmd/compile/internal/types2/typestring.go | 22 +++++++++++-------- 2 files changed, 14 insertions(+), 10 deletions(-) diff --git a/src/cmd/compile/internal/types2/infer.go b/src/cmd/compile/internal/types2/infer.go index a3772aa7131..ff4bb3ea175 100644 --- a/src/cmd/compile/internal/types2/infer.go +++ b/src/cmd/compile/internal/types2/infer.go @@ -83,7 +83,7 @@ func (check *Checker) infer(pos syntax.Pos, tparams []*TypeName, targs []Type, p // Substitute type arguments for their respective type parameters in params, // if any. Note that nil targs entries are ignored by check.subst. - // TODO(gri) Can we avoid this (we're setting known type argumemts below, + // TODO(gri) Can we avoid this (we're setting known type arguments below, // but that doesn't impact the isParameterized check for now). if params.Len() > 0 { smap := makeSubstMap(tparams, targs) diff --git a/src/cmd/compile/internal/types2/typestring.go b/src/cmd/compile/internal/types2/typestring.go index b3675424a5b..ead17ba2f3c 100644 --- a/src/cmd/compile/internal/types2/typestring.go +++ b/src/cmd/compile/internal/types2/typestring.go @@ -246,23 +246,27 @@ func writeTParamList(buf *bytes.Buffer, list []*TypeName, qf Qualifier, visited buf.WriteString("[") var prev Type for i, p := range list { - // TODO(gri) support 'any' sugar here. - var b Type = &emptyInterface - if t, _ := p.typ.(*TypeParam); t != nil && t.bound != nil { - b = t.bound + // Determine the type parameter and its constraint. + // list is expected to hold type parameter names, + // but don't crash if that's not the case. + tpar, _ := p.typ.(*TypeParam) + var bound Type + if tpar != nil { + bound = tpar.bound // should not be nil but we want to see it if it is } + if i > 0 { - if b != prev { - // type bound changed - write previous one before advancing + if bound != prev { + // bound changed - write previous one before advancing buf.WriteByte(' ') writeType(buf, prev, qf, visited) } buf.WriteString(", ") } - prev = b + prev = bound - if t, _ := p.typ.(*TypeParam); t != nil { - writeType(buf, t, qf, visited) + if tpar != nil { + writeType(buf, tpar, qf, visited) } else { buf.WriteString(p.name) }