Method process

src/pre_processor.rs:58–92

(
        &mut self,
        span: &mut Span,
        suppress: &FxHashSet<SmolStr>,
    )

    }

    fn process(
        &mut self,
        span: &mut Span,
        suppress: &FxHashSet<SmolStr>,
    ) -> Result<(), Diagnostic> {
        let mut dirty = false;
        *self.i = span.start;
        while *self.i < span.end {
            if let Some(define_name) = self.parse_define_begin(span)? {
                if self.parse_function_define(span, define_name.clone())? {
                    continue;
                }
                self.parse_simple_define(span, define_name)?;
                continue;
            }
            if self.parse_undef(span)? {
                continue;
            }
            if self.substitute_simple_define(span, suppress)? {
                continue;
            }
            if self.substitute_function_define(span, suppress)? {
                continue;
            }
            if self.substitute_concat(span)? {
                dirty = true;
                continue;
            }
            *self.i += 1;
        }
        if dirty {
            self.process(span, suppress)?;
        }
        Ok(())
    }

    fn remove_marker_tokens(&mut self) {
        self.tokens.retain(|token| {