expr_explode doesn't take into account operator precedence

[tcr]

Right now it does a linear scan for the first operator, then splits an expression into two. Operator precedence would split at the highest-precedence operators first, then iterate on the subsections.

fn expr_explode(span: Vec<Expr>) -> Vec<Expr> {
    ...
    for i in 0..span.len() {
        if let &ast::Expr::Operator(ref op) = &span[i] {
            return vec![ast::Expr::Op(
                Box::new(Expr::Span(expr_explode(span[0..i].to_vec().clone()))),
                op.to_string(),
                Box::new(Expr::Span(expr_explode(span[i+1..].to_vec().clone()))),
            )];
        }
    }
    span
}

[pshc]

Oh so that's what Spans are.

[tcr]

Haha, yeah. I think Spans should be refactored into type + arguments or expr + argument vectors, and operator parsing and precedence should be imposed by LALRPOP (see its tutorials for examples). The concept works in practice but isn't really correct.

[pshc]

Yeah, doing it all in the parser would be nicest.