adding template description for merge requests

templates for issues and merge_requests for specific user information and better analysis of tradeoffs of certain features

Tom Almeida authored Mar 17, 2020 and AdminXVII committed Apr 20, 2020

Before this patch, `let` only shows string and array variables, whilst
all mapping types are not shown. In addition, string and array variables
are separated from each other by comments.

This patch implements a new function on `shell::Variables` that returns
all the variables in scope and then modifies `Shell::list_vars` to print
all the variables. The syntax returned is equivalent to the method of
declaring the variables themselves, however this still results in
mapping types being indistinguishable from each other by looking at the
output of `let` (both `HashMap` and `BTreeMap` look the same).

Tom Almeida authored Mar 18, 2020 and AdminXVII committed Apr 20, 2020

Why is this needed?
Well, at the moment nothing happens when the user tries something along
the lines of `let some_string[3] = 'v'`, even though we don't allow it.
The variable itself doesn't change, and we don't print any errors.
This patch just makes the function that would assign return an error
instead of silently failing.

Why not implement modifying strings by index?
Sure, we could do that, but it's not quite as obvious as it seems. We
support utf8 strings, so modifying the `i`th byte obviously doesn't
work, and could potentially make the string invalid. Another option
would be to set the `i`th character to whatever is passed in. This is
fine in theory, but it would be an `O(N)` operation in the average
case, and we'd have to shuffle all the following chars either further up
or further down the string.
While this may be a desirable ability to eventually have, it will
require significantly more work and thought around strings in ion than
simply returning an error.

Tom Almeida authored Mar 16, 2020 and AdminXVII committed Apr 20, 2020

Prior to this commit, the following type was considered invalid:
    `[[float]]`

Of course, sometimes it is helpful to have arrays within arrays, and as
such, this patch allows for nested arrays. To do this, the array types
in `Primitive` have all been converted to a `Primitive::Array` type,
that holds a `Box<>` to another `Primitive`. There is - of course - a
slight performance penalty to be expected with moving to using another
`Box` for arrays, however after having run the benchmarks, the
difference appears to be negligible.

When some binaries set the TTY to non-blocking mode, the shell would panic because of a nonblock error. Fix this by reseting the O_FLAGS while reading lines

Avoid recompiling the regexset for each value, it is wasteful.
Add start and end anchor to match the full value with the regex by default

TODO: Does the regex crate have an option for this?

dardyfella authored Jan 12, 2020 and Michael Aaron Murphy committed Jan 12, 2020

Fixes the issue where:

```
let arg = todo
echo -e "\n\n$arg"
```

Returns:

```

ntodo
```

Instead of:

```

todo
```

---

Fixes issue where:

```
echo -e "one\\\\\ntwo\\\\\nthree"
```

Returns:

```
one\\ntwo\\nthree
```

Instead of:

```
one\
two\
three
```

AdminXVII authored Dec 14, 2019 and Michael Aaron Murphy committed Jan 12, 2020

Many tools rely on the current shell being a POSIX shell to set
environments (ex: Nix). Add the `source-sh` builtin which spawns the sh
shell, and then sync the new environment variables.

Also, a update the new fmt

BuggStream authored Dec 09, 2019 and Michael Aaron Murphy committed Jan 12, 2020

The variable is equal to the amount of WHOLE seconds spent executing the
previous command.

This variable is currently not set when running the PROMPT function,
because this would mean that the CMD_DURATION would always refer to
the time spent in the PROMPT function when running in interactive mode.

AdminXVII authored Sep 05, 2019 and Michael Aaron Murphy committed Jan 12, 2020

- Disable the regex's unicode feature by default
- Add a feature to Ion to enable it again
- Update the dependencies

Breaking Change: Perl-style character class are disabled (\w _et al._) and
there is no longer unicode support by default.

AdminXVII authored Sep 04, 2019 and Michael Aaron Murphy committed Jan 12, 2020

- Adds a merge request guidelines section
- Switch to squashed, conventional-style commits for MRs
- Specify preference for rebase over merges
- Link to a resource explaining a recommended git flow

AdminXVII authored Aug 12, 2019 and Michael Aaron Murphy committed Jan 12, 2020

Breaking Change: auto-cd will no longer wrk in scripts. However, it was
never intended to work in scripts to begin with, so this is actually an
improvement.

If a command fails, try to cd before outputing the error.

Issues fixed by this:
 - Trailing slashes are no longer necessary
 - If a binary and a folder conflicts, the binary has priority
 - Typing `-` cd to the old pwd

Fix #892