diff options
Diffstat (limited to 'src/runtime/error.go')
| -rw-r--r-- | src/runtime/error.go | 33 |
1 files changed, 19 insertions, 14 deletions
diff --git a/src/runtime/error.go b/src/runtime/error.go index 1f77c0a0b5..9a2beaeb95 100644 --- a/src/runtime/error.go +++ b/src/runtime/error.go @@ -19,32 +19,37 @@ type Error interface { // A TypeAssertionError explains a failed type assertion. type TypeAssertionError struct { - interfaceString string - concreteString string - assertedString string - missingMethod string // one method needed by Interface, missing from Concrete + _interface *_type + concrete *_type + asserted *_type + missingMethod string // one method needed by Interface, missing from Concrete } func (*TypeAssertionError) RuntimeError() {} func (e *TypeAssertionError) Error() string { - inter := e.interfaceString - if inter == "" { - inter = "interface" + inter := "interface" + if e._interface != nil { + inter = e._interface.string() } - if e.concreteString == "" { - return "interface conversion: " + inter + " is nil, not " + e.assertedString + as := e.asserted.string() + if e.concrete == nil { + return "interface conversion: " + inter + " is nil, not " + as } + cs := e.concrete.string() if e.missingMethod == "" { - msg := "interface conversion: " + inter + " is " + e.concreteString + - ", not " + e.assertedString - if e.concreteString == e.assertedString { + msg := "interface conversion: " + inter + " is " + cs + ", not " + as + if cs == as { // provide slightly clearer error message - msg += " (types from different packages)" + if e.concrete.pkgpath() != e.asserted.pkgpath() { + msg += " (types from different packages)" + } else { + msg += " (types from different scopes)" + } } return msg } - return "interface conversion: " + e.concreteString + " is not " + e.assertedString + + return "interface conversion: " + cs + " is not " + as + ": missing method " + e.missingMethod } |