Enum ParameterSubstitution

pub enum ParameterSubstitution<P, W, C, A> {
    Command(Vec<C>),
    Len(P),
    Arith(Option<A>),
    Default(bool, P, Option<W>),
    Assign(bool, P, Option<W>),
    Error(bool, P, Option<W>),
    Alternative(bool, P, Option<W>),
    RemoveSmallestSuffix(P, Option<W>),
    RemoveLargestSuffix(P, Option<W>),
    RemoveSmallestPrefix(P, Option<W>),
    RemoveLargestPrefix(P, Option<W>),
}

A parameter substitution, e.g. ${param-word}.

Generic over the representations of parameters, shell words and commands, and arithmetic expansions.

Variants

Command(Vec<C>)

Returns the standard output of running a command, e.g. $(cmd)

Len(P)

Returns the length of the value of a parameter, e.g. ${#param}

Arith(Option<A>)

Returns the resulting value of an arithmetic subsitution, e.g. $(( x++ ))

Default(bool, P, Option<W>)

Use a provided value if the parameter is null or unset, e.g. ${param:-[word]}. The boolean indicates the presence of a :, and that if the parameter has a null value, that situation should be treated as if the parameter is unset.

Assign(bool, P, Option<W>)

Assign a provided value to the parameter if it is null or unset, e.g. ${param:=[word]}. The boolean indicates the presence of a :, and that if the parameter has a null value, that situation should be treated as if the parameter is unset.

Error(bool, P, Option<W>)

If the parameter is null or unset, an error should result with the provided message, e.g. ${param:?[word]}. The boolean indicates the presence of a :, and that if the parameter has a null value, that situation should be treated as if the parameter is unset.

Alternative(bool, P, Option<W>)

If the parameter is NOT null or unset, a provided word will be used, e.g. ${param:+[word]}. The boolean indicates the presence of a :, and that if the parameter has a null value, that situation should be treated as if the parameter is unset.

RemoveSmallestSuffix(P, Option<W>)

Remove smallest suffix pattern from a parameter’s value, e.g. ${param%pattern}

RemoveLargestSuffix(P, Option<W>)

Remove largest suffix pattern from a parameter’s value, e.g. ${param%%pattern}

RemoveSmallestPrefix(P, Option<W>)

Remove smallest prefix pattern from a parameter’s value, e.g. ${param#pattern}

RemoveLargestPrefix(P, Option<W>)

Remove largest prefix pattern from a parameter’s value, e.g. ${param##pattern}

Trait Implementations

impl<P: Clone, W: Clone, C: Clone, A: Clone> Clone for ParameterSubstitution<P, W, C, A>

fn clone(&self) -> ParameterSubstitution<P, W, C, A>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<P: Debug, W: Debug, C: Debug, A: Debug> Debug for ParameterSubstitution<P, W, C, A>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<P: PartialEq, W: PartialEq, C: PartialEq, A: PartialEq> PartialEq for ParameterSubstitution<P, W, C, A>

fn eq(&self, other: &ParameterSubstitution<P, W, C, A>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<P: Eq, W: Eq, C: Eq, A: Eq> Eq for ParameterSubstitution<P, W, C, A>

impl<P, W, C, A> StructuralPartialEq for ParameterSubstitution<P, W, C, A>