doc_9_testing_12345 0.1.0

use self::ParseMoneyError::*;

#[derive(Debug,PartialEq)]
pub enum ParseMoneyError {
    SymbolErr,
    NoStringErr, 
    TwoPointsErr,
    NonDigitErr(char),
    TooFarErr,
}


pub fn parse_sym_money(s:&str,sym:char,dpoint:usize)->Result<i32,ParseMoneyError>{
    let (c,v) = parse_money(s,dpoint)?;
    if c != sym {
        return Err(ParseMoneyError::SymbolErr);
    }
    Ok(v)
}


pub fn parse_money(s:&str,dpoint:usize)->Result<(char,i32),ParseMoneyError>{
    let mut it = s.trim().chars();
    let mut neg = false; 

    let mut r_sym = it.next().ok_or(NoStringErr)?;
    if '-' == r_sym {
        neg = true;
        r_sym = it.next().ok_or(NoStringErr)?;
    }

    let mut res:i32 = 0;
    let mut point_pos:Option<usize> = None;
    for c in it {
        //check on point
        if c == '.' {
            if point_pos != None {
                return Err(TwoPointsErr);
            }
            point_pos = Some(0);
            continue;
        }

        if c < '0' || c > '9' {
            return Err(NonDigitErr(c));
        }
        res *= 10;
        res += c as i32 - 48;

        //confirm not too many digits after point
        if let Some(pp) = point_pos {
            point_pos = Some(pp+1);
            if pp >= dpoint{
                return Err(TooFarErr)
            }
        }
    }

    for _ in point_pos.unwrap_or(0)..dpoint {
        res *=10;
    }

    if neg {
        res = -res;
    }
    
    Ok((r_sym,res))

}

#[cfg(test)]
mod tests{
    use super::*;

    #[test]
    fn parseany(){
        let (c,v) = parse_money("£34.3",2).unwrap();
        assert_eq!(c,'£');
        assert_eq!(v,3430);

        assert!(parse_money("£34.304",2).is_err());
        assert!(parse_money("£34..04",2).is_err());

        assert_eq!(parse_money("£.34",2),Ok(('£',34)));
    }

    #[test]
    fn parse_sym(){
        assert_eq!(parse_sym_money("£34.3",'£',2),Ok(3430));
        assert_eq!(parse_sym_money("-£34", '£',2),Ok(-3400));
        assert!(parse_sym_money("£34", '$',2).is_err());
        assert!(parse_sym_money("-£34", '$',2).is_err());
    }

}