lookup2.go

     1  // Copyright 2024 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 p
     6  
     7  import (
     8  	"go/ast"
     9  	"math/big"
    10  )
    11  
    12  // case           sel     pkg   have   message (examples for general lookup)
    13  // ---------------------------------------------------------------------------------------------------------
    14  // ok             x.Foo   ==    Foo
    15  // misspelled     x.Foo   ==    FoO    type X has no field or method Foo, but does have field FoO
    16  // misspelled     x.Foo   ==    foo    type X has no field or method Foo, but does have field foo
    17  // misspelled     x.Foo   ==    foO    type X has no field or method Foo, but does have field foO
    18  //
    19  // misspelled     x.foo   ==    Foo    type X has no field or method foo, but does have field Foo
    20  // misspelled     x.foo   ==    FoO    type X has no field or method foo, but does have field FoO
    21  // ok             x.foo   ==    foo
    22  // misspelled     x.foo   ==    foO    type X has no field or method foo, but does have field foO
    23  //
    24  // ok             x.Foo   !=    Foo
    25  // misspelled     x.Foo   !=    FoO    type X has no field or method Foo, but does have field FoO
    26  // unexported     x.Foo   !=    foo    type X has no field or method Foo, but does have unexported field foo
    27  // missing        x.Foo   !=    foO    type X has no field or method Foo
    28  //
    29  // misspelled     x.foo   !=    Foo    type X has no field or method foo, but does have field Foo
    30  // missing        x.foo   !=    FoO    type X has no field or method foo
    31  // inaccessible   x.foo   !=    foo    cannot refer to unexported field foo
    32  // missing        x.foo   !=    foO    type X has no field or method foo
    33  
    34  type S struct {
    35  	Foo1 int
    36  	FoO2 int
    37  	foo3 int
    38  	foO4 int
    39  }
    40  
    41  func _() {
    42  	var x S
    43  	_ = x.Foo1 // OK
    44  	_ = x.Foo2 // ERROR "x.Foo2 undefined (type S has no field or method Foo2, but does have field FoO2)"
    45  	_ = x.Foo3 // ERROR "x.Foo3 undefined (type S has no field or method Foo3, but does have field foo3)"
    46  	_ = x.Foo4 // ERROR "x.Foo4 undefined (type S has no field or method Foo4, but does have field foO4)"
    47  
    48  	_ = x.foo1 // ERROR "x.foo1 undefined (type S has no field or method foo1, but does have field Foo1)"
    49  	_ = x.foo2 // ERROR "x.foo2 undefined (type S has no field or method foo2, but does have field FoO2)"
    50  	_ = x.foo3 // OK
    51  	_ = x.foo4 // ERROR "x.foo4 undefined (type S has no field or method foo4, but does have field foO4)"
    52  }
    53  
    54  func _() {
    55  	_ = S{Foo1: 0} // OK
    56  	_ = S{Foo2 /* ERROR "unknown field Foo2 in struct literal of type S, but does have FoO2" */ : 0}
    57  	_ = S{Foo3 /* ERROR "unknown field Foo3 in struct literal of type S, but does have foo3" */ : 0}
    58  	_ = S{Foo4 /* ERROR "unknown field Foo4 in struct literal of type S, but does have foO4" */ : 0}
    59  
    60  	_ = S{foo1 /* ERROR "unknown field foo1 in struct literal of type S, but does have Foo1" */ : 0}
    61  	_ = S{foo2 /* ERROR "unknown field foo2 in struct literal of type S, but does have FoO2" */ : 0}
    62  	_ = S{foo3: 0} // OK
    63  	_ = S{foo4 /* ERROR "unknown field foo4 in struct literal of type S, but does have foO4" */ : 0}
    64  }
    65  
    66  // The following tests follow the same pattern as above but operate on an imported type instead of S.
    67  // Currently our testing framework doesn't make it easy to define an imported package for testing, so
    68  // instead we use the big.Float and ast.File types as they provide a suitable mix of exported and un-
    69  // exported fields and methods.
    70  
    71  func _() {
    72  	var x *big.Float
    73  	_ = x.Neg  // OK
    74  	_ = x.NeG  // ERROR "x.NeG undefined (type *big.Float has no field or method NeG, but does have method Neg)"
    75  	_ = x.Form // ERROR "x.Form undefined (type *big.Float has no field or method Form, but does have unexported field form)"
    76  	_ = x.ForM // ERROR "x.ForM undefined (type *big.Float has no field or method ForM)"
    77  
    78  	_ = x.abs  // ERROR "x.abs undefined (type *big.Float has no field or method abs, but does have method Abs)"
    79  	_ = x.abS  // ERROR "x.abS undefined (type *big.Float has no field or method abS)"
    80  	_ = x.form // ERROR "x.form undefined (cannot refer to unexported field form)"
    81  	_ = x.forM // ERROR "x.forM undefined (type *big.Float has no field or method forM)"
    82  }
    83  
    84  func _() {
    85  	_ = ast.File{Name: nil} // OK
    86  	_ = ast.File{NamE /* ERROR "unknown field NamE in struct literal of type ast.File, but does have Name" */ : nil}
    87  	_ = big.Float{Form /* ERROR "unknown field Form in struct literal of type big.Float, but does have unexported form" */ : 0}
    88  	_ = big.Float{ForM /* ERROR "unknown field ForM in struct literal of type big.Float" */ : 0}
    89  
    90  	_ = ast.File{name /* ERROR "unknown field name in struct literal of type ast.File, but does have Name" */ : nil}
    91  	_ = ast.File{namE /* ERROR "unknown field namE in struct literal of type ast.File" */ : nil}
    92  	_ = big.Float{form /* ERROR "cannot refer to unexported field form in struct literal of type big.Float" */ : 0}
    93  	_ = big.Float{forM /* ERROR "unknown field forM in struct literal of type big.Float" */ : 0}
    94  }
    95
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