There are some cases where you need to have an argument to have an
alias, an example could be when you depricate one option in favor of
another one.
Now you are going to be able to alias arguments as follows:
```
Arg::with_name("opt")
.long("opt")
.short("o")
.takes_value(true)
.alias("invisible")
.visible_alias("visible")
```
Closes#669
* feat: adds App::with_defaults to automatically use crate_authors! and crate_version! macros
One can now use
```rust
let a = App::with_defaults("My Program");
// same as
let a2 = App::new("My Program")
.version(crate_version!())
.author(crate_authors!());
```
Closes#600
* imp(YAML Errors): vastly improves error messages when using YAML
When errors are made while developing, the panic error messages have
been improved instead of relying on the default panic message which is
extremely unhelpful.
Closes#574
* imp(Completions): uses standard conventions for bash completion files, namely '{bin}.bash-completion'
Closes#567
* imp(Help): automatically moves help text to the next line and wraps when term width is determined to be too small, or help text is too long
Now `clap` will check if it should automatically place long help
messages on the next line after the flag/option. This is determined by
checking to see if the space taken by flag/option plus spaces and values
doesn't leave enough room for the entirety of the help message, with the
single exception of of if the flag/option/spaces/values is less than 25%
of the width.
Closes#597
* tests: updates help tests to new forced new line rules
* fix(Groups): fixes some usage strings that contain both args in groups and ones that conflict with each other
Args that conflict *and* are in a group will now only display in the
group and not in the usage string itself.
Closes#616
* chore: updates dep graph
Closes#633
* chore: clippy run
* style: changes debug header to match other Rust projects
* chore: increase version
* test: `require_unless_one` with second argument
Add the `require_unless_one_2` test. This tests that when the second
argument in the array is used at the command line, that the required
argument is not present. This test was added because it appears the
`require_unless_one` function only works for the first argument in the
array.
* Fix: assertions for test
The assertions did not check for the `infile` to be present.
The strategy is to copy the template from the the reader to wrapped stream
until a tag is found. Depending on its value, the appropriate content is copied
to the wrapped stream.
The copy from template is then resumed, repeating this sequence until reading
the complete template.
Tags arg given inside curly brackets:
Valid tags are:
* `{bin}` - Binary name.
* `{version}` - Version number.
* `{author}` - Author information.
* `{usage}` - Automatically generated or given usage string.
* `{all-args}` - Help for all arguments (options, flags, positionals arguments,
and subcommands) including titles.
* `{unified}` - Unified help for options and flags.
* `{flags}` - Help for flags.
* `{options}` - Help for options.
* `{positionals}` - Help for positionals arguments.
* `{subcommands}` - Help for subcommands.
* `{after-help}` - Help for flags.
The largest organizational change is that methods used to generate the help are
implemented by the Help object and not the App, FlagBuilder, Parser, etc.
The new code is based heavily on the old one with a few minor modifications
aimed to reduce code duplication and coupling between the Help and the rest
of the code.
The new code turn things around: instead of having a HelpWriter that holds an
AnyArg object and a method that is called with a writer as argument,
there is a Help Object that holds a writer and a method that is called with a
writer as an argument.
There are still things to do such as moving `create_usage` outside the Parser.
The peformance has been affected, probably by the use of Trait Objects. This
was done as a way to reduce code duplication (i.e. in the unified help code).
This performance hit should not affect the usability as generating and printing
the help is dominated by user interaction and IO.
The old code to generate the help is still functional and is the active one.
The new code has been tested against the old one by generating help strings
for most of the examples in the repo.
The method `starts_with` as implemented for the `OsStrExt2` trait on
`OsStr` assumed that the needle given is shorter than the haystack. When
this is not the case, the method panics due to an attempted
out-of-bounds access on the byte representation of `self`. Problematic
if, say, an end-user gives us `"-"` and the library tries to see if that
starts with `"--"`.
Fortunately, slices already implement a `starts_with` method, and we can
delegate to it.
This *does* create a semantics change: if both `self` and the needle
have length 0, this implementation will return `true`, but the old
implementation would return `false`. Based on the test suite still
passing, acknowledging the vacuous truth doesn't seem to cause any
problems.
Fixes#410
Tons of code has been moved into functions, deduplicated, made much
easier to read, maintain, and understand. Comments still need to be
added, but that will happen shortly. Modules have also been moved around
to follow Rust conventions and best practices.
All functionality remains exactly the same
