Allow negative numbers as positional arguments

[SpecificProtagonist]

Fixes #191

This implementation prioritises recognized flags over positional arguments in the case of ambiguity.

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[correabuscar]

Try a cargo test, it doesn't pass the tests¹ for me unless I revert it.

test subcommand_example ... ok
test fuchsia_commandline_tools_rubric::keyed_no_equals ... FAILED
test missing_option_value ... FAILED
test options::parsed ... FAILED
test redact_arg_values_produces_errors_with_bad_arguments ... FAILED

failures:

---- fuchsia_commandline_tools_rubric::keyed_no_equals stdout ----
thread 'fuchsia_commandline_tools_rubric::keyed_no_equals' panicked at /home/user/1tmp/argh/argh/tests/lib.rs:928:9:
assertion `left == right` failed
  left: "Unrecognized argument: --foo=bar\n"
 right: "Unrecognized argument: \"--foo=bar\". Did you mean \"--foo\"?\n"
stack backtrace:
   0: rust_begin_unwind
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/std/src/panicking.rs:652:5
   1: core::panicking::panic_fmt
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/panicking.rs:72:14
   2: core::panicking::assert_failed_inner
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/panicking.rs:409:17
   3: core::panicking::assert_failed
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/panicking.rs:364:5
   4: lib::fuchsia_commandline_tools_rubric::keyed_no_equals
             at ./tests/lib.rs:928:9
   5: lib::fuchsia_commandline_tools_rubric::keyed_no_equals::{{closure}}
             at ./tests/lib.rs:922:25
   6: core::ops::function::FnOnce::call_once
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/ops/function.rs:250:5
   7: core::ops::function::FnOnce::call_once
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/ops/function.rs:250:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

---- missing_option_value stdout ----
thread 'missing_option_value' panicked at /home/user/1tmp/argh/argh/tests/lib.rs:436:5:
assertion `left == right` failed
  left: "Unrecognized argument: --msg\n"
 right: "No value provided for option '--msg'.\n"
stack backtrace:
   0: rust_begin_unwind
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/std/src/panicking.rs:652:5
   1: core::panicking::panic_fmt
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/panicking.rs:72:14
   2: core::panicking::assert_failed_inner
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/panicking.rs:409:17
   3: core::panicking::assert_failed
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/panicking.rs:364:5
   4: lib::missing_option_value
             at ./tests/lib.rs:436:5
   5: lib::missing_option_value::{{closure}}
             at ./tests/lib.rs:425:26
   6: core::ops::function::FnOnce::call_once
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/ops/function.rs:250:5
   7: core::ops::function::FnOnce::call_once
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/ops/function.rs:250:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

---- options::parsed stdout ----
thread 'options::parsed' panicked at /home/user/1tmp/argh/argh/tests/lib.rs:457:5:
assertion `left == right` failed
  left: "Error parsing option '-n' with value 'x': invalid digit found in string\n"
 right: "Unrecognized argument: -n\n"
stack backtrace:
   0: rust_begin_unwind
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/std/src/panicking.rs:652:5
   1: core::panicking::panic_fmt
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/panicking.rs:72:14
   2: core::panicking::assert_failed_inner
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/panicking.rs:409:17
   3: core::panicking::assert_failed
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/panicking.rs:364:5
   4: lib::assert_error
             at ./tests/lib.rs:457:5
   5: lib::options::parsed
             at ./tests/lib.rs:475:9
   6: lib::options::parsed::{{closure}}
             at ./tests/lib.rs:473:16
   7: core::ops::function::FnOnce::call_once
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/ops/function.rs:250:5
   8: core::ops::function::FnOnce::call_once
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/ops/function.rs:250:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

---- redact_arg_values_produces_errors_with_bad_arguments stdout ----
thread 'redact_arg_values_produces_errors_with_bad_arguments' panicked at /home/user/1tmp/argh/argh/tests/lib.rs:1706:5:
assertion `left == right` failed
  left: Err(EarlyExit { output: "Unrecognized argument: --n\n", status: Err(()) })
 right: Err(EarlyExit { output: "No value provided for option '--n'.\n", status: Err(()) })
stack backtrace:
   0: rust_begin_unwind
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/std/src/panicking.rs:652:5
   1: core::panicking::panic_fmt
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/panicking.rs:72:14
   2: core::panicking::assert_failed_inner
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/panicking.rs:409:17
   3: core::panicking::assert_failed
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/panicking.rs:364:5
   4: lib::redact_arg_values_produces_errors_with_bad_arguments
             at ./tests/lib.rs:1706:5
   5: lib::redact_arg_values_produces_errors_with_bad_arguments::{{closure}}
             at ./tests/lib.rs:1697:58
   6: core::ops::function::FnOnce::call_once
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/ops/function.rs:250:5
   7: core::ops::function::FnOnce::call_once
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/ops/function.rs:250:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.


failures:
    fuchsia_commandline_tools_rubric::keyed_no_equals
    missing_option_value
    options::parsed
    redact_arg_values_produces_errors_with_bad_arguments

test result: FAILED. 69 passed; 4 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.04s

error: test failed, to rerun pass `-p argh --test lib`

Alternatively trying this:

use argh::FromArgs;

#[derive(FromArgs)]
/// Reach new heights.
struct GoUp {
    /// whether or not to jump
    #[argh(switch, short = 'j')]
    jump: bool,

    /// how high to go
    #[argh(option)]
    height: usize,

    /// an optional nickname for the pilot
    #[argh(option)]
    pilot_nickname: Option<String>,
}

fn main() {
    let up: GoUp = argh::from_env();
}

bad output:

$ ./target/debug/test_negatives --height
Unrecognized argument: --height

Run test_negatives --help for more information.

which should be(if reverted):

$ ./target/debug/test_negatives --height
No value provided for option '--height'.

Run test_negatives --help for more information.

but this works:

$ ./target/debug/test_negatives --height 1

Footnotes

1. ignoring the irrelevant one (depending on your rust version) argh/tests/ui/conflicting-tails/positional-and-greedy.stderr which only has differing output. ↩