just/src/functions.rs

37 lines
882 B
Rust

use crate::common::*;
pub struct Functions<'a> {
stack: Vec<&'a Expression<'a>>,
}
impl<'a> Functions<'a> {
pub fn new(root: &'a Expression<'a>) -> Functions<'a> {
Functions { stack: vec![root] }
}
}
impl<'a> Iterator for Functions<'a> {
type Item = (&'a Token<'a>, usize);
fn next(&mut self) -> Option<Self::Item> {
match self.stack.pop() {
None
| Some(Expression::String { .. })
| Some(Expression::Backtick { .. })
| Some(Expression::Variable { .. }) => None,
Some(Expression::Call {
token, arguments, ..
}) => Some((token, arguments.len())),
Some(Expression::Concatination { lhs, rhs }) => {
self.stack.push(lhs);
self.stack.push(rhs);
self.next()
}
Some(Expression::Group { expression }) => {
self.stack.push(expression);
self.next()
}
}
}
}