After cloning anu, despite seeming to have the fixes from #11 and #5, I still have newlines missing from my Cargo.toml files, so cargo build doesn’t work.

Once I add those newlines in again myself and use anu diff to see my changes, I see a diff that looks very different than the change I actually made:

$ anu diff libanu/Cargo.toml 
message = ''
timestamp = '2020-11-06T23:36:56.053801176Z'
authors = []

# Dependencies
[2] SL52FT2SJFQMOA2H25WXCYJBY4Z4ATQOAEIGDQULLLNZGLTIL3IAC
[3]+Y67GBRYQ6WCAKFJKZJYNCSON7AMN2KRH5T745MQ3OMZCUA2SM5UAC
[4]+HYNHP3MNRNAAS5VJNBWP664PE5OTL7IT5WN7WDTN4KHCSI2URIYAC

# Changes

1. Replacement in libanu/Cargo.toml:3 3.803852
  :D, 2.291 -> 2.291:314/2, 2.314 -> 4.121:168/2, 3.803903 -> 4.121:168/4
  up 2.291, new 0:71, down 2.315
- version = "1.0.0-alpha"
- repository = "https://nest.anu.dev/anu/libanu"
- repository = "https://nest.anu.dev/anu/libanu"
+ version = "1.0.0-alpha"
+ repository = "https://nest.anu.dev/anu/libanu"
+

2. Replacement in libanu/Cargo.toml:6 3.803852
  :D, 2.356 -> 2.356:408/2, 2.408 -> 3.803956:803973/2, 3.803956 -> 3.803956:803973/3
  up 2.356, new 72:142, down 4.209
- authors = ["Pierre-Étienne Meunier <pe@pijul.org>"]
- edition = "2018"
- edition = "2018"
+ authors = ["Pierre-Étienne Meunier <pe@pijul.org>"]
+ edition = "2018"
+

3. Replacement in libanu/Cargo.toml:103 3.803852
  :D, 2.430 -> 2.430:445/2, 2.445 -> 3.804519:804541/2, 3.804519 -> 3.804519:804541/3
  up 2.430, new 143:181, down 3.804541
- bincode = "1.3"
- data-encoding = "2.3"
- data-encoding = "2.3"
+ bincode = "1.3"
+ data-encoding = "2.3"
+

Here is a session showing steps, along with a manual backup of the file and diff using diff:

$ anu clone 51.210.158.166:22/anu/anu
$ anu diff libanu/Cargo.toml

# ... edit in my editor ...

$ diff -u libanu/Cargo.toml{.bak,}
--- libanu/Cargo.toml.bak	2020-11-06 18:45:57.805823045 -0500
+++ libanu/Cargo.toml	2020-11-06 18:46:48.880560170 -0500
@@ -1,9 +1,11 @@
 [package]
 name = "libanu"
 description = "Core library of Anu, a distributed version control system based on a sound theory of collaborative work."
-version = "1.0.0-alpha"repository = "https://nest.anu.dev/anu/libanu"
+version = "1.0.0-alpha"
+repository = "https://nest.anu.dev/anu/libanu"
 documentation = "https://docs.rs/libanu"
-authors = ["Pierre-Étienne Meunier <pe@pijul.org>"]edition = "2018"
+authors = ["Pierre-Étienne Meunier <pe@pijul.org>"]
+edition = "2018"
 license = "GPL-2.0"
 include = [
 "Cargo.toml",
@@ -99,7 +101,8 @@
 blake3 = "0.3"
 chrono = { version = "0.4", features = ["serde"] }
 anu-macros = "0.1.0"
-bincode = "1.3"data-encoding = "2.3"
+bincode = "1.3"
+data-encoding = "2.3"
 lru-cache = "0.1"
 diffs = "0.4"
 tempfile = "3.1"

$ anu diff libanu/Cargo.toml
message = ''
timestamp = '2020-11-06T23:46:58.699276658Z'
authors = []

# Dependencies
[2] SL52FT2SJFQMOA2H25WXCYJBY4Z4ATQOAEIGDQULLLNZGLTIL3IAC
[3]+Y67GBRYQ6WCAKFJKZJYNCSON7AMN2KRH5T745MQ3OMZCUA2SM5UAC
[4]+HYNHP3MNRNAAS5VJNBWP664PE5OTL7IT5WN7WDTN4KHCSI2URIYAC

# Changes

1. Replacement in libanu/Cargo.toml:3 3.803852
  :D, 2.291 -> 2.291:314/2, 2.314 -> 4.121:168/2, 3.803903 -> 4.121:168/4
  up 2.291, new 0:71, down 2.315
- version = "1.0.0-alpha"
- repository = "https://nest.anu.dev/anu/libanu"
- repository = "https://nest.anu.dev/anu/libanu"
+ version = "1.0.0-alpha"
+ repository = "https://nest.anu.dev/anu/libanu"
+

2. Replacement in libanu/Cargo.toml:6 3.803852
  :D, 2.356 -> 2.356:408/2, 2.408 -> 3.803956:803973/2, 3.803956 -> 3.803956:803973/3
  up 2.356, new 72:142, down 4.209
- authors = ["Pierre-Étienne Meunier <pe@pijul.org>"]
- edition = "2018"
- edition = "2018"
+ authors = ["Pierre-Étienne Meunier <pe@pijul.org>"]
+ edition = "2018"
+

3. Replacement in libanu/Cargo.toml:103 3.803852
  :D, 2.430 -> 2.430:445/2, 2.445 -> 3.804519:804541/2, 3.804519 -> 3.804519:804541/3
  up 2.430, new 143:181, down 3.804541
- bincode = "1.3"
- data-encoding = "2.3"
- data-encoding = "2.3"
+ bincode = "1.3"
+ data-encoding = "2.3"
+

So for some reason, the diff shows three predecessor lines, when there was only one line in the actual file in my working directory, and it shows 3 new lines, two of which match the predecessor lines and one of which is a blank line at the end that I did not add; I added a newline in between the two other lines, to break up the two lines which had gotten merged together somehow.

Refer to #13

This is due to the trickiest part of libanu: change parsing. The internal representation of changes is tricky, and Pijul used to provide an interactive sequence of questions to make a change. I believe this new scheme offers much more flexibility, but requires (1) a stable text format to describe the changes (the binary format itself is stable), and (2) a parser for it.

Unfortunately, only real-world usage can tell if the text format is good enough. And since I don’t actuvely work on any other project at the moment, Anu itself is a good test case, even if that means going through some of these UI hiccups for the first release.

This particular problem with newlines is fixed in #3EAIT2277UKYK2SGAWNR4GRP3IIJGMH6ANJ3JGBZMKNYRW7OOCVQC.

I have explained in the following blog post how the whole thing works: https://pijul.org/posts/2020-11-07-towards-1.0/

In particular, deleted lines are not part of the change, they’re mostly a decoration here. The only things that matter for deletions are the lines of the form :D, 2.291 -> 2.291:314/2, 2.314 -> 4.121:168/2, 3.803903 -> 4.121:168/4.