Struct libslide::parser::errors::IllegalVariable

pub(crate) struct IllegalVariable;

Variables are illegal in a slide expression pattern.

In most cases, this error is fired because you intended to evaluate an expression with slide, or wrote a variable in place of a variable pattern.

Because expression patterns are meant to abstract over and match expressions, there is generally not a need to explicitly define the name of a variable to be matched by an expression pattern. Rather, the concern is generally with the shape of the variable; that is, that it is actually a variable. For this use case, the "${name}" pattern (where "{name}" is a text placeholder) serves as a variable-matching pattern.

As a concrete example, the expression pattern $a + $b + $a matches both the expressions a + b + a and b + a + b. Both expressions are lowered the same way despite having different variable names, so variable patterns permit abstraction and common representation over the names.

Trait Implementations

impl DiagnosticRecord for IllegalVariable

const CODE: &'static str

Diagnostic code.

const EXPLANATION: &'static str

Detailed diagnostic explanation.