I reimplemented remaining() method for backward compatibility.
It consumes "all" remaining args.
So, I added mAcceptsOptionalLikeValue flag and handle it by using this
flag.
Currently, remaining() behavior is slightly different from the original when no
args are provided and get<Container<T>>() method is called.
Originally it raises an exception. But current implementation returns
an empty container instead of exception.
It is possible to implement complete backward compatibility by
referencing mAcceptsOptionalLikeValue flag and raises an exception in get() method,
but I did not do this.
I think that is too much.
To handle variable length nargs, I replaced mNumArgs with mNumArgsRange.
I defined SizeRange class for mNumArgsRange, which has simply min and
max std::size_t member.
To concentrate on this big change, I tentatively deleted remaining
feature, which was originally implemented in the way that mNumArgs = -1
internally and maybe_args() -> Optional wrap method.
Library users may make use of 4 types of interface to set
mNumArgsRange.
1. nargs(std::size_t)
2. nargs(std::size_t, std::size_t)
3. nargs(SizeRange)
4. nargs(NArgsPattern)
1. is expected to behave same as original. This mthod sets min=max
SizeRange to mNumArgsRange, which is actually, not a range, but an
"exact" number.
2. sets min and max.
3. uses SizeRange class. This interface may be unnecessary. It is also
an option to delete this method and make SizeRange class internal.
4. is provided to set common patterns. In Python, they are "?", "*" and
"+". NArgsPattern is an enum class for type safety. std::string
interface is also an option to mimic Python argparse. char interface
would be ambiguous with 1.
Changes on consume method is important.
The parser tries to consume args until the count reaches mNumArgsRanges::max or
it meets another optional like string.
If consumed args count is under mNumArgsRanges::min, the parser fails.
Now, when the required number of arguments are not provided, the parser
will fail.
So, we have to take care of get() method as well.
get() failed when argument count is 0 and default value not provided.
But now there are 0..1 or 0..* nargs are OK.
So this behaviour has to be fixed.
When T is container_v, it returns empty container.
I implemented validate method so that it shows kind message.
If the developer forgot to call ArgumentParser::parse_args<>, attempts to
use ::get, ::present, etc., would raise "No value provided...". With this
change, the error better describes what went wrong.
Signed-off-by: Sean Robinson <sean.robinson@scottsdalecc.edu>
Here, the user gave an argument name but failed to provide the required
parameters to the argument. Tell the user which argument wants more.
This is an API change that may affect programs trying to match the
specific "Too few arguments" message. The new error message appends the
user-supplied argument that caused the error.
A solution which works with both versions is to look for "Too few
arguments" at the beginning of the error message.
- if (err.what() == "Too few arguments")
+ if (std:string(err.what()).rfind("Too few arguments", 0) == 0)
Signed-off-by: Sean Robinson <sean.robinson@scottsdalecc.edu>
As the user did not include the argument, the longest name for the unused
argument is in the last position of mNames.
This is an API change that may affect programs trying to match the
specific "No value provided" message. The new error message appends the
argument that caused the error.
A solution which works with both versions is to look for "No value
provided" at the beginning of the error message.
- if (err.what() == "No value provided")
+ if (std:string(err.what()).rfind("No value provided", 0) == 0)
Signed-off-by: Sean Robinson <sean.robinson@scottsdalecc.edu>
It's too early to use std::chars_format as there is not wide enough
support in stdlib implementations. After the following stdlib become our
supported versions, this can be revisited.
GCC >= 10.1.0
Clang >= 7.0.0 (already our minimum)
MSVC >= 19.4
Reverts commit 1c61082a4c.
Signed-off-by: Sean Robinson <sean.robinson@scottsdalecc.edu>
I believe the Supported Toolchains all now include <charconv> (and
std::chars_format) and we can use the stdlib-defined values.
Signed-off-by: Sean Robinson <sean.robinson@scottsdalecc.edu>
.present returns std::nullopt if the optional argument is not given by the
user -- as long as a .default_value is not defined. With a .default_value,
.present cannot be used to determine if a value is user-provided or the
default.
.is_used fills that role and only returns true if the argument was passed
by the user.
Signed-off-by: Sean Robinson <sean.robinson@scottsdalecc.edu>
The default behavior with optional arguments is to allow only a single use
per invocation. One alternative is to use .nargs, but this requires
previously knowing, and limiting, the quantity of values. The .append
method removes the restriction on repeats for a single Argument.
Signed-off-by: Sean Robinson <sean.robinson@scottsdalecc.edu>
While the implicit conversions from `1` to `true` work correctly, this
avoids the conversions.
Signed-off-by: Sean Robinson <sean.robinson@scottsdalecc.edu>
Previously, it printed ": expected 1 argument(s). 0 provided." when one positional argument is defined but nothing is provided. Now it prints "1 argument(s) expected. 0 provided."
Two differences that diverge from the existing behavior:
1. Leading zeros are not allowed for integers. Negative
octal numbers such as `-066` are not meant to be treated
as positional arguments, but existing code recognize them
as decimal numbers. Note that negative floating-point
numbers with leading zeros (`-003.`) are unambiguous and
are recognized.
2. Inf and NaN are not recognized. This is because options
like `-inf` is indistinguishable from a compound argument
that meant to be a shorthand for `-i -n -f`.
fixes: p-ranav/argparse#55
The change also fixes a rare bug introduced in 9007958:
when there are duplicated keys, insert_or_update overrides
previously inserted ones, emplace doesn't.
fixes: p-ranav/argparse#59
