Change-Id: Iae4855c52c4da9755277251d22121226507ea26a Reviewed-on: https://go-review.googlesource.com/23074 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Fixes #15339 Change-Id: I0b006deefb58ccfc47beae4e1b8da3d77fafda6b Reviewed-on: https://go-review.googlesource.com/22148 Reviewed-by: Rob Pike <r@golang.org>
Documentation change only. Fixes #15178. Change-Id: I3c7d80ce9e668ac7515f7ebb9da80f3bd8e534d6 Reviewed-on: https://go-review.googlesource.com/22006 Reviewed-by: Ian Lance Taylor <iant@golang.org>
fmt docs say: If the operand is a reflect.Value, the concrete value it holds is printed as if it was the operand. It implies recursive application of this rule, which is not the case. Clarify the docs. Change-Id: I019277c7c6439095bab83e5536aa06403638aa51 Reviewed-on: https://go-review.googlesource.com/15952 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Fixes #12340. Change-Id: I17a8b3711a8593ec60882a0dcadb38f0cc138f4b Reviewed-on: https://go-review.googlesource.com/13949 Reviewed-by: Rob Pike <r@golang.org>
Also improve the documentation. A prior fix in this release changed the properties for empty strings and slices, incorrectly. Previous behavior is now restored and better documented. Add lots of tests. The behavior is that when using a string-like format (%s %q %x %X) a byte slice is equivalent to a string, and printed as a unit. The padding applies to the entire object. (The space and sharp flags apply elementwise.) Fixes #11422. Fixes #10430. Change-Id: I758f0521caf71630437e43990ec6d6c9a92655e3 Reviewed-on: https://go-review.googlesource.com/11600 Reviewed-by: Russ Cox <rsc@golang.org>
When scanning with a width, as in %5s, C skips leading spaces brefore counting the 5 characters. We should do the same. Reword the documentation about widths to make this clear. Fixes #9444 Change-Id: I443a6441adcf1c834057ef3977f9116a987a79cd Reviewed-on: https://go-review.googlesource.com/10997 Reviewed-by: Andrew Gerrand <adg@golang.org>
The documentation says that newlines behave like this: Scan etc.: newlines are spaces. Scanln etc.: newlines terminate the scan. Scanf etc.: newlines must match in input and format. The code did not implement this behavior in all cases, especially for Scanf. Make it behave: - Fix the handling of spaces and newlines in ss.Advance. The code is longer but now behaves as it should. - Delete the reuse of the current ss in newScanState. There is really no need, since it's only used in recursive calls to Scan etc., and the flags are likely wrong. Simpler just to allocate a new one every time, and likelier to be correct. Fixes #10862. Change-Id: If060ac021017346723b0d62de4e5a305da898f68 Reviewed-on: https://go-review.googlesource.com/10991 Reviewed-by: Andrew Gerrand <adg@golang.org>
When a reflect.Value is passed to Printf (etc.), fmt called the String method, which does not disclose its contents. To get the contents, one could call Value.Interface(), but that is illegal if the Value is not exported or otherwise forbidden. This CL improves the situation with a trivial change to the fmt package: when we see a reflect.Value as an argument, we treat it exactly as we treat a reflect.Value we make inside the package. This means that we always print the contents of the Value as if _that_ was the argument to Printf. This is arguably a breaking change but I think it is a genuine improvement and no greater a break than many other tweaks we have made to formatted output from this package. Fixes #8965. Change-Id: Ifc2a4ce3c1134ad5160e101d2196c22f1542faab Reviewed-on: https://go-review.googlesource.com/8731 Reviewed-by: roger peppe <rogpeppe@gmail.com> Reviewed-by: Russ Cox <rsc@golang.org>
If a method called by fmt triggers a panic, the output usually says so. However, there is heretofore undocumented special treatment for a panic caused by formatting a nil value with an Error or String method: the output is simply "<nil>". Document that behavior. Change-Id: Id0f79dd0b3487f9d1c74a0856727bba5cc342be4 Reviewed-on: https://go-review.googlesource.com/6410 Reviewed-by: David Crawshaw <crawshaw@golang.org>