added godoc
diff --git a/errors.go b/errors.go
index dcc1456..31ca468 100644
--- a/errors.go
+++ b/errors.go
@@ -6,23 +6,41 @@
"io"
"os"
"runtime"
+ "strings"
)
+type loc uintptr
+
+func (l loc) Location() (string, int) {
+ pc := uintptr(l)
+ fn := runtime.FuncForPC(pc)
+ if fn == nil {
+ return "unknown", 0
+ }
+
+ _, prefix, _, _ := runtime.Caller(0)
+ file, line := fn.FileLine(pc)
+ if i := strings.LastIndex(prefix, "github.com/pkg/errors"); i > 0 {
+ file = file[i:]
+ }
+ return file, line
+}
+
// New returns an error that formats as the given text.
func New(text string) error {
return struct {
error
- pc uintptr
+ loc
}{
fmt.Errorf(text),
- pc(),
+ loc(pc()),
}
}
type e struct {
cause error
message string
- pc uintptr
+ loc
}
func (e *e) Error() string {
@@ -42,7 +60,7 @@
return &e{
cause: cause,
message: message,
- pc: pc(),
+ loc: loc(pc()),
}
}
@@ -77,6 +95,15 @@
}
// Print prints the error to Stderr.
+// If the error implements the Causer interface described in Cause
+// Print will recurse into the error's cause.
+// If the error implements the inteface:
+//
+// type Location interface {
+// Location() (file string, line int)
+// }
+//
+// Print will also print the file and line of the error.
func Print(err error) {
Fprint(os.Stderr, err)
}
@@ -89,7 +116,7 @@
location, ok := err.(locationer)
if ok {
file, line := location.Location()
- fmt.Fprint(w, "%s:%d: ", file, line)
+ fmt.Fprintf(w, "%s:%d: ", file, line)
}
switch err := err.(type) {
case *e:
diff --git a/errors_test.go b/errors_test.go
index 2eb3de7..220a4f9 100644
--- a/errors_test.go
+++ b/errors_test.go
@@ -124,10 +124,10 @@
want: "error\n",
}, {
err: Wrap(x, "message"),
- want: "message\nerror\n",
+ want: "github.com/pkg/errors/errors_test.go:126: message\nerror\n",
}, {
err: Wrap(Wrap(x, "message"), "another message"),
- want: "another message\nmessage\nerror\n",
+ want: "github.com/pkg/errors/errors_test.go:129: another message\ngithub.com/pkg/errors/errors_test.go:129: message\nerror\n",
}}
for i, tt := range tests {
diff --git a/example_test.go b/example_test.go
index 3c72e4f..98c0ac7 100644
--- a/example_test.go
+++ b/example_test.go
@@ -23,7 +23,10 @@
}
func fn() error {
- return errors.Wrap(errors.Wrap(errors.Wrap(errors.New("error"), "inner"), "middle"), "outer")
+ e1 := errors.New("error")
+ e2 := errors.Wrap(e1, "inner")
+ e3 := errors.Wrap(e2, "middle")
+ return errors.Wrap(e3, "outer")
}
func ExampleCause() {
@@ -39,8 +42,8 @@
err := fn()
errors.Fprint(os.Stdout, err)
- // Output: outer
- // middle
- // inner
+ // Output: github.com/pkg/errors/example_test.go:29: outer
+ // github.com/pkg/errors/example_test.go:28: middle
+ // github.com/pkg/errors/example_test.go:27: inner
// error
}
