6d95e5a4ff
This enables a consumer of a CSV to find out the position of a CSV field without implementing an intermediate buffer. This is useful to produce good higher level error messages when the CSV syntax is OK but the field values don't match expectations. This also changes the existing semantics of the `ParseError.Column` field to bring it in line with precedent elsewhere in the Go standard library (notably go/token.Position) - the column is now 1-based and indicates a byte count rather than a rune count, and the error position reporting at the end of a last line without a newline is now fixed. This change has some impact on performance: ``` name old time/op new time/op delta Read-8 2.14µs ± 0% 2.15µs ± 0% ~ (p=0.056 n=5+5) ReadWithFieldsPerRecord-8 2.15µs ± 2% 2.15µs ± 1% ~ (p=0.151 n=5+5) ReadWithoutFieldsPerRecord-8 2.15µs ± 0% 2.15µs ± 0% +0.37% (p=0.024 n=5+5) ReadLargeFields-8 3.55µs ± 2% 3.59µs ± 0% ~ (p=0.206 n=5+5) ReadReuseRecord-8 1.18µs ± 1% 1.22µs ± 1% +2.93% (p=0.008 n=5+5) ReadReuseRecordWithFieldsPerRecord-8 1.18µs ± 0% 1.21µs ± 0% +2.54% (p=0.008 n=5+5) ReadReuseRecordWithoutFieldsPerRecord-8 1.18µs ± 0% 1.22µs ± 1% +3.66% (p=0.008 n=5+5) ReadReuseRecordLargeFields-8 2.53µs ± 1% 2.57µs ± 1% +1.70% (p=0.008 n=5+5) Write-8 1.02µs ± 1% 1.01µs ± 0% -1.18% (p=0.016 n=5+4) ``` Fixes #44221. Change-Id: Id37c50fc396024eef406c5bad45380ecd414f5ea Reviewed-on: https://go-review.googlesource.com/c/go/+/291290 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Trust: Paul Jolly <paul@myitcv.org.uk> |
||
|---|---|---|
| .github | ||
| api | ||
| doc | ||
| lib/time | ||
| misc | ||
| src | ||
| test | ||
| .gitattributes | ||
| .gitignore | ||
| AUTHORS | ||
| CONTRIBUTING.md | ||
| CONTRIBUTORS | ||
| LICENSE | ||
| PATENTS | ||
| README.md | ||
| SECURITY.md | ||
| codereview.cfg | ||
README.md
The Go Programming Language
Go is an open source programming language that makes it easy to build simple, reliable, and efficient software.
Gopher image by Renee French, licensed under Creative Commons 3.0 Attributions license.
Our canonical Git repository is located at https://go.googlesource.com/go. There is a mirror of the repository at https://github.com/golang/go.
Unless otherwise noted, the Go source files are distributed under the BSD-style license found in the LICENSE file.
Download and Install
Binary Distributions
Official binary distributions are available at https://golang.org/dl/.
After downloading a binary release, visit https://golang.org/doc/install for installation instructions.
Install From Source
If a binary distribution is not available for your combination of operating system and architecture, visit https://golang.org/doc/install/source for source installation instructions.
Contributing
Go is the work of thousands of contributors. We appreciate your help!
To contribute, please read the contribution guidelines at https://golang.org/doc/contribute.html.
Note that the Go project uses the issue tracker for bug reports and proposals only. See https://golang.org/wiki/Questions for a list of places to ask questions about the Go language.