diff options
| -rw-r--r-- | src/go/types/typeparam.go | 34 |
1 files changed, 21 insertions, 13 deletions
diff --git a/src/go/types/typeparam.go b/src/go/types/typeparam.go index a3d60c1648..8cb44ea25e 100644 --- a/src/go/types/typeparam.go +++ b/src/go/types/typeparam.go @@ -60,24 +60,32 @@ func (t *TypeParam) _SetId(id uint64) { t.id = id } -// TODO(rfindley): document the Bound and SetBound methods. +// Constraint returns the type constraint specified for t. +func (t *TypeParam) Constraint() Type { + // compute the type set if possible (we may not have an interface) + if iface, _ := under(t.bound).(*Interface); iface != nil { + // use the type bound position if we have one + pos := token.NoPos + if n, _ := t.bound.(*Named); n != nil { + pos = n.obj.pos + } + computeTypeSet(t.check, pos, iface) + } + return t.bound +} +// Bound returns the underlying type of the type parameter's +// constraint. +// Deprecated for external use. Use Constraint instead. func (t *TypeParam) Bound() *Interface { - // we may not have an interface (error reported elsewhere) - iface, _ := under(t.bound).(*Interface) - if iface == nil { - return &emptyInterface + if iface, _ := under(t.Constraint()).(*Interface); iface != nil { + return iface } - // use the type bound position if we have one - pos := token.NoPos - if n, _ := t.bound.(*Named); n != nil { - pos = n.obj.pos - } - // TODO(rFindley) switch this to an unexported method on Checker. - computeTypeSet(t.check, pos, iface) - return iface + return &emptyInterface } +// TODO(rfindley): document the SetBound methods. + func (t *TypeParam) SetBound(bound Type) { if bound == nil { panic("internal error: bound must not be nil") |