github.com/cockroachdb/tools@v0.0.0-20230222021103-a6d27438930d/go/types/typeutil/ui.go (about)

     1  // Copyright 2014 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package typeutil
     6  
     7  // This file defines utilities for user interfaces that display types.
     8  
     9  import "go/types"
    10  
    11  // IntuitiveMethodSet returns the intuitive method set of a type T,
    12  // which is the set of methods you can call on an addressable value of
    13  // that type.
    14  //
    15  // The result always contains MethodSet(T), and is exactly MethodSet(T)
    16  // for interface types and for pointer-to-concrete types.
    17  // For all other concrete types T, the result additionally
    18  // contains each method belonging to *T if there is no identically
    19  // named method on T itself.
    20  //
    21  // This corresponds to user intuition about method sets;
    22  // this function is intended only for user interfaces.
    23  //
    24  // The order of the result is as for types.MethodSet(T).
    25  func IntuitiveMethodSet(T types.Type, msets *MethodSetCache) []*types.Selection {
    26  	isPointerToConcrete := func(T types.Type) bool {
    27  		ptr, ok := T.(*types.Pointer)
    28  		return ok && !types.IsInterface(ptr.Elem())
    29  	}
    30  
    31  	var result []*types.Selection
    32  	mset := msets.MethodSet(T)
    33  	if types.IsInterface(T) || isPointerToConcrete(T) {
    34  		for i, n := 0, mset.Len(); i < n; i++ {
    35  			result = append(result, mset.At(i))
    36  		}
    37  	} else {
    38  		// T is some other concrete type.
    39  		// Report methods of T and *T, preferring those of T.
    40  		pmset := msets.MethodSet(types.NewPointer(T))
    41  		for i, n := 0, pmset.Len(); i < n; i++ {
    42  			meth := pmset.At(i)
    43  			if m := mset.Lookup(meth.Obj().Pkg(), meth.Obj().Name()); m != nil {
    44  				meth = m
    45  			}
    46  			result = append(result, meth)
    47  		}
    48  
    49  	}
    50  	return result
    51  }