What is the rationale for Elvish behaving as if the equivalent of doing
set -o errexit in bash/zsh/ksh is always in effect? That is the only behavior that will keep me from using Elvish on a daily basis and contributing to its development given my reading of the documentation and experimenting with the implementation for a few days. Simply running a command like grep that might return a non-zero exit status for a non-fatal reason (e.g., nothing matched the pattern) should not be a fatal error by default. It is unreasonable to be required to wrap every command of thaat nature in a try { command } except { } block.
Also, I've read the "unique semantics" document. Specifically the section "Exit Status and Exceptions". The problem is it says "Elvish has no concept of exit status". Then goes on to say that an external commands non-zero exit status is turned into an exception. Which is okay if explicitly enabled but should not be the default behavior.
[xiaq] If so: no. External command interaction is a fundamental shell feature, and it is a sign of poor design to make such fundamental semantics customizable. We can think about how to document it better, how to make it more ergonomic. Or getting rid of it. But making it customizable solves no problem
I am not sure how to deal with this. The same discussion has occurred in the Fish shell project. What I do believe, quite strongly, is that a non-zero exit status of an external command should not be a fatal error by default. There are too many commands which exit with a non-zero status that do not indicate a fatal error.
The canonical example being
grep but it is by no means the only example.
If I write a elvish script that invokes such commands it is unreasonable to require me to wrap every invocation in a
try { } except { } block.
And that doesn't even work unless you do it in the context of something like
if ?(echo abc | grep a) { ... }.
[xiaq] Another is filtering lines that contain a string. In that case you need to suppress the exception when grep finds no match and exits with 1. I have long wanted to provide a syntax for that but you see I am really lazy :)
[xiaq] AFAIK, most commands exit with 1 on non-fatal errors, and it would be nice to be able to suppress such errors.
I'm having trouble defining an edit:arg-completer for git. Here's what I've got in my rc.elv (basically just copied from the documented recipe):
# git branch completion
all-git-branches = [(e:git branch -a --format="%(refname:strip=2)" | eawk [0 1 @rest]{ put $1 })]
edit:arg-completer[git] = [args]{
n = (count $args)
if (eq $n 2) {
put st co rebase stash
} elif (ge $n 3) {
put $@all-git-branches
}
}my git commands sometimes will do filename completion, but other than that all I get is the "unsupported completion :(" message
[xiaqqaix] Elvish is a cross-platform shell, supporting Linux, BSDs and Windows. It features an expressive programming language, with features like namespacing and anonymous functions, and a fully programmable user interface with friendly defaults. It is suitable for both interactive use and scripting.
[xiaqqaix] Draft of the release note: http://draft.elvish.io/blog/0.11-release-notes.html You are all invited to review it! :) But please do not share this draft elsewhere yet
[zhsj] Would it possible to add changelog in the code repo?
[zzamboni] @xiaqqaix sounds good to me
[xiaqqaix] It feels a bit too much a hassle to announce it now, only to announce some big changes next version
[zzamboni] yes, makes sense
[zhsj] Would it possible to add changelog in the code repo?
[xiaqqaix] I haven't considered that before. What's the advantage?
[xofyarg] apt changelog elvish
[xofyarg] apt changelog elvish
[zhsj] no, apt changlog will not show changlog of upstream
[xiaqqaix] Although on the other hand, I am considering merging the website repo into the main code repo
[zzamboni] @xiaqqaix was there a way to forward-declare a function, so it can be used before its body appears in the file?
[zzamboni] I seem to remember something about it, but can't find it
[zzamboni] sorry, this is more for the other group
[xiaqqaix] Does that require the changelog to be in the same code repo? I would be a bit surprised if it does
[zhsj] So I can ship changlog in package (though I think nobody will read it
[xiaqqaix] Does that require the changelog to be in the same code repo? I would be a bit surprised if it does
[zhsj] So I can ship changlog in package's document (though I think nobody will read it
[zhsj] If the documents merged into main repo, we can also generate man pages
It looks like its built for doing pipelines from terminal ?
on ALl Desktop OS's which is amazingly useful
Ping? I just noticed this Gitter channel for the Elvish project. The previous message was almost a year ago. Just wondering if anyone still pays attention to this channel. The only reference in the project is in file ./website/blog/newsletter-july-2017.md which is almost three years old.
I think there is value in a discussion channel devoted to developers rather than users of
elvish which should use the https://gitter.im/elves/elvish URI for asking questions. But it seems like 99.999% of messages in the past year are on the latter channel. I am thus wondering whether this channel should be documented.