eltl 0.7.0

An engineer's calculator. Written in Rust.
Documentation 
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//! A parselet for parentheticals.

use crate::parselet_utils::*;
use crate::error::*;

pub struct ParenParselet;

impl PrefixParselet for ParenParselet {
    fn parse(&self, parser: &Parser, tokenizer: &mut Tokenizer, _token: Token) -> Expression {
        // Get the expression inside the parenthetical
        let next = match tokenizer.peek() {
            Some(t) => t,
            None => {
                throw(UnexpectedEof);
                return Expression::Nil;
            },
        };

        let expr = parser.parse(tokenizer, next.get_class().into());

        let next = match tokenizer.peek() {
            Some(t) => t,
            None => {
                throw(UnexpectedEof);
                return Expression::Nil;
            },
        };

        if next.get_class() == TokenClass::CloseParen {
            // Consume the parenthesis
            tokenizer.next();
            
            expr
        } else {
            throw(ExpectedCloseParen);
            return Expression::Nil;
        }
    }
}