# [Question] How to parse range-diff output 4 messages from 2024-02-26 to 2024-02-29. Participants: ZheNing Hu, Kristoffer Haugsbakk, Junio C Hamano. Thread: https://gitlist.dev/t/61006 ## ZheNing Hu, 2024-02-26 07:25 Subject: [Question] How to parse range-diff output Message-ID: URL: https://gitlist.dev/e/CAOLTT8SQyBSWC%3DaqB2SRYmp3kR6RZ%2BL_-9yckWQf-X9rbzeNBw%40mail.gmail.com ``` Hi, I am currently looking to implement a service that provides a version range comparison based on git range-diff. I can easily parse out commit pair headers like "3: 0bf6289 ! 3: a076e88 dev5," but I am unsure how to parse the details in the subsequent diff patch body. It is not a standard diff output where one can parse out the filename from the diff header, It should be called a diff of diffs. We can see various headers with file names such as "@@ File1 (new)", "## File2 (new) ##", or "@@ File3: function3" in different formats. This is confusing. How should we correctly parse a range-diff patch, and do you have any good suggestions? Thanks for any help. -- ZheNing Hu ``` ## Kristoffer Haugsbakk, 2024-02-26 13:16 Subject: Re: [Question] How to parse range-diff output Message-ID: <11783b8e-472d-4b75-bb48-88138daf16ae@app.fastmail.com> URL: https://gitlist.dev/e/11783b8e-472d-4b75-bb48-88138daf16ae%40app.fastmail.com In-Reply-To: ``` On Mon, Feb 26, 2024, at 08:25, ZheNing Hu wrote: > Hi, > > I am currently looking to implement a service that provides a version > range comparison based on git range-diff. I can easily parse out > commit pair headers like "3: 0bf6289 ! 3: a076e88 dev5," but I am > unsure how to parse the details in the subsequent diff patch body. > > It is not a standard diff output where one can parse out the filename > from the diff header, It should be called a diff of diffs. We can see > various headers with file names such as "@@ File1 (new)", "## File2 > (new) ##", or "@@ File3: function3" in different formats. This is > confusing. How should we correctly parse a range-diff patch, and do > you have any good suggestions? > > Thanks for any help. > -- > ZheNing Hu Hi Note that “Output Stability” says that this output is not meant to be machine-readable. It’s for human consumption. It’s not textually stable. So a new version of Git might break your implementation without warning. -- Kristoffer Haugsbakk ``` ## Junio C Hamano, 2024-02-26 16:16 Subject: Re: [Question] How to parse range-diff output Message-ID: URL: https://gitlist.dev/e/xmqqmsrnfbfh.fsf%40gitster.g In-Reply-To: <11783b8e-472d-4b75-bb48-88138daf16ae@app.fastmail.com> ``` "Kristoffer Haugsbakk" writes: > On Mon, Feb 26, 2024, at 08:25, ZheNing Hu wrote: >> Hi, >> >> I am currently looking to implement a service that provides a version >> range comparison based on git range-diff. I can easily parse out >> commit pair headers like "3: 0bf6289 ! 3: a076e88 dev5," but I am >> unsure how to parse the details in the subsequent diff patch body. >> >> It is not a standard diff output where one can parse out the filename >> from the diff header, It should be called a diff of diffs. We can see >> various headers with file names such as "@@ File1 (new)", "## File2 >> (new) ##", or "@@ File3: function3" in different formats. This is >> confusing. How should we correctly parse a range-diff patch, and do >> you have any good suggestions? >> >> Thanks for any help. >> -- >> ZheNing Hu > > Hi > > Note that “Output Stability” says that this output is not meant to be > machine-readable. It’s for human consumption. It’s not textually stable. > > So a new version of Git might break your implementation without warning. Good point. In fact, those "##" things came long after the command was introduced for exactly the purpose of helping human users to locate which part of a "diff" the "diff of diff" is talking about, and the output from the command has been unstable for the exact reason. ``` ## ZheNing Hu, 2024-02-29 11:00 Subject: Re: [Question] How to parse range-diff output Message-ID: URL: https://gitlist.dev/e/CAOLTT8Sn89Qq68YpTCsiK%2B_WAPdrsTN1xWxpkuEbhwBWpZgK%3DA%40mail.gmail.com In-Reply-To: <11783b8e-472d-4b75-bb48-88138daf16ae@app.fastmail.com> ``` Kristoffer Haugsbakk 于2024年2月26日周一 21:16写道： > > On Mon, Feb 26, 2024, at 08:25, ZheNing Hu wrote: > > Hi, > > > > I am currently looking to implement a service that provides a version > > range comparison based on git range-diff. I can easily parse out > > commit pair headers like "3: 0bf6289 ! 3: a076e88 dev5," but I am > > unsure how to parse the details in the subsequent diff patch body. > > > > It is not a standard diff output where one can parse out the filename > > from the diff header, It should be called a diff of diffs. We can see > > various headers with file names such as "@@ File1 (new)", "## File2 > > (new) ##", or "@@ File3: function3" in different formats. This is > > confusing. How should we correctly parse a range-diff patch, and do > > you have any good suggestions? > > > > Thanks for any help. > > -- > > ZheNing Hu > > Hi > > Note that “Output Stability” says that this output is not meant to be > machine-readable. It’s for human consumption. It’s not textually stable. > > So a new version of Git might break your implementation without warning. > It is very regrettable that some crucial metadata from the range-diff patch cannot be extracted. I can only hope that future range-diff will have the capability of being machine-readable. Thank you! > -- > Kristoffer Haugsbakk ```