Struct ap::Settings [−][src]
pub struct Settings { /* fields omitted */ }
Expand description
Settings used to control the parsers behaviour.
Implementations
impl Settings
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impl Settings
[src]pub fn ignore_unknown_options(self) -> Self
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pub fn ignore_unknown_options(self) -> Self
[src]Specify that unknown options should be silently ignored (by default, the first unknown option will generate an error).
pub fn ignore_unknown_posn_args(self) -> Self
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pub fn ignore_unknown_posn_args(self) -> Self
[src]Specify that unknown positional arguments should be silently ignored (by default, they will generate an error).
pub fn no_strict_options(self) -> Self
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pub fn no_strict_options(self) -> Self
[src]By default, arguments are parsed as they would be by getopt(3)
whereby if an option is marked as requiring a value
(Need::Argument) and the option is found on the command line, the
next argument (whether it starts with a dash or not!) is “consumed” as
the options argument.
However, when this setting is enabled, option values cannot start with a dash.
Advice
- If you want to your program to behave like the traditional
getopt(3)
, leave this setting unset. - If you need your program to accept an argument starting with a dash (for example, you have an option which could accept a negative number), you should leave this setting unset.
- If your program provides options and flags and you wish to minimse
the chance of a flag (particularly a numeric flag such as
-1
or-2
) being interpreted as an options value, consider setting this option to disable support for option values starting with a dash.
Example
If a program accepts a flag (-f
) and an option that
requires an value (-r <value>
) and the following command-line is
specified to the program…
$ prog -r -f
… the outcome of the parse will depend on this setting:
-
If
no_strict_options=false
(the default), the command line will be passed successfully and ther
option (Arg) will be given the value “-f
” and thef
option (Arg) will be considered to not have been specified.Note:
This is how the POSIX command line argument
getopt(3)
works. -
If
no_strict_options=true
, the parse will fail with the errorError::MissingOptArg
since in this mode, option values may not begin with a dash so the-f
is treated as the next argument meaning the user forgot to specify a value for the previous argument (-r
), which is an error.Note:
This is an alternative behaviour adopted by some modern command line argument parsers.
Trait Implementations
impl Ord for Settings
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impl Ord for Settings
[src]impl PartialOrd<Settings> for Settings
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impl PartialOrd<Settings> for Settings
[src]fn partial_cmp(&self, other: &Settings) -> Option<Ordering>
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fn partial_cmp(&self, other: &Settings) -> Option<Ordering>
[src]This method returns an ordering between self
and other
values if one exists. Read more
#[must_use]fn lt(&self, other: &Rhs) -> bool
1.0.0[src]
#[must_use]fn lt(&self, other: &Rhs) -> bool
1.0.0[src]This method tests less than (for self
and other
) and is used by the <
operator. Read more
#[must_use]fn le(&self, other: &Rhs) -> bool
1.0.0[src]
#[must_use]fn le(&self, other: &Rhs) -> bool
1.0.0[src]This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
impl Copy for Settings
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impl Eq for Settings
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impl StructuralEq for Settings
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impl StructuralPartialEq for Settings
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Auto Trait Implementations
impl RefUnwindSafe for Settings
impl Send for Settings
impl Sync for Settings
impl Unpin for Settings
impl UnwindSafe for Settings
Blanket Implementations
impl<T> BorrowMut<T> for T where
T: ?Sized,
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impl<T> BorrowMut<T> for T where
T: ?Sized,
[src]pub fn borrow_mut(&mut self) -> &mut T
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pub fn borrow_mut(&mut self) -> &mut T
[src]Mutably borrows from an owned value. Read more
impl<T> ToOwned for T where
T: Clone,
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impl<T> ToOwned for T where
T: Clone,
[src]type Owned = T
type Owned = T
The resulting type after obtaining ownership.
pub fn to_owned(&self) -> T
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pub fn to_owned(&self) -> T
[src]Creates owned data from borrowed data, usually by cloning. Read more
pub fn clone_into(&self, target: &mut T)
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pub fn clone_into(&self, target: &mut T)
[src]🔬 This is a nightly-only experimental API. (toowned_clone_into
)
recently added
Uses borrowed data to replace owned data, usually by cloning. Read more