labast/src/parse.rs

use crate::{errors::ParseError, stack::{Instruction, Stack}};

pub fn parse(stack: &mut Stack, file_content: &str) {
    for (i, line) in file_content.lines().enumerate() {
        if line.trim().starts_with(';') || line.is_empty() {
            continue;
        }

        let inst_line: String;
        if let Some(comment_index) = line.trim().find(';') {
            inst_line = line.trim().chars().take(comment_index).collect();
        } else {
            inst_line = line.trim().chars().collect();
        }

        let command: Vec<String> = inst_line.split_whitespace().map(String::from).collect();

        let name: String;
        let mut arg: String = String::new();
        let mut data: u16 = 0;

        name = command[0].clone();

        if command.len() >= 2 {
            match name.chars().nth(0) {
                Some('#') => arg = command[1].to_string(),
                _ => {
                    if command[1] == "-1" { // required for _UNIX_RANDOM instruction
                        data = 65535;
                    } else {
                        data = command[1].parse().expect(&format!("{}", ParseError::DataNotAUInt(command[0].to_string(), i + 1)))
                    }
                }
            }
        }

        let inst = Instruction { name, arg, data };
        stack.program.push(inst);
    }
}