Enum Expression

pub enum Expression {
    Subproc(SpannableNode<String>),
    If {
        this: SpannableNode<Disjunct>,
        then: SpannableNode<Disjunct>,
        else: Option<Box<SpannableNode<Expression>>>,
    },
    Disjunct(SpannableNode<Disjunct>),
}

An expression in the WAGon attribute evaluation DSL.

Grammar

Expression -> SubProc | If | Disjunct;
SubProc -> "$(" /[^)]*/ ")"; // A bash-style $() expression
If -> “if” Disjunct “then” Disjunct (“else” Expression)?;

Variants

Subproc(SpannableNode<String>)

A subprocess that should do evaluation in the shell.

If

An if(-else) statement.

Fields

this: SpannableNode<Disjunct>

If this evaluation returns true.

then: SpannableNode<Disjunct>

Do this.

else: Option<Box<SpannableNode<Expression>>>

Else, evaluate this expression.

Disjunct(SpannableNode<Disjunct>)

The next layer down. See Disjunct.

Implementations

impl Expression

pub fn new_unspanned_subproc(arg_0: String) -> Self

Construct a Self::Subproc with dummy span information.

pub fn new_unspanned_disjunct(arg_0: Disjunct) -> Self

Construct a Self::Disjunct with dummy span information.

Trait Implementations

impl Clone for Expression

fn clone(&self) -> Expression

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Expression

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

Formats the value using the given formatter.

impl Display for Expression

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

Formats the value using the given formatter.

impl Hash for Expression

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Parse for Expression

fn parse(lexer: &mut LexerBridge<'_>) -> ParseResult<Self>

Given a lexer, try to parse a valid instance of this node.

fn parse_sep( lexer: &mut LexerBridge<'_>, join: Tokens, ) -> ParseResult<Vec<Self>>

where Self: Sized,

Parse multiple instances of this node, separated by a Tokens.

fn parse_sep_end( lexer: &mut LexerBridge<'_>, join: Tokens, end: Tokens, ) -> ParseResult<Vec<Self>>

where Self: Sized,

Parse multiple instances of this node, separated by a Tokens end ended by a (possibly different) Tokens.

impl PartialEq for Expression

fn eq(&self, other: &Expression) -> 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 Eq for Expression

impl StructuralPartialEq for Expression