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extern crate num_traits;
use std::fmt;
use std::str::FromStr;
use tokenizer::{PeekableTokens, Token};
use FromTokens;
#[derive(Default)]
pub struct Coord<T>
where
T: num_traits::Float,
{
pub x: T,
pub y: T,
pub z: Option<T>,
pub m: Option<T>,
}
impl<T> fmt::Display for Coord<T>
where
T: num_traits::Float + fmt::Display,
{
fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
write!(f, "{} {}", self.x, self.y)?;
if let Some(z) = self.z {
write!(f, " {}", z)?;
}
if let Some(m) = self.m {
write!(f, " {}", m)?;
}
Ok(())
}
}
impl<T> FromTokens<T> for Coord<T>
where
T: num_traits::Float + FromStr + Default,
{
fn from_tokens(tokens: &mut PeekableTokens<T>) -> Result<Self, &'static str> {
let x = match tokens.next() {
Some(Token::Number(n)) => n,
_ => return Err("Expected a number for the X coordinate"),
};
let y = match tokens.next() {
Some(Token::Number(n)) => n,
_ => return Err("Expected a number for the Y coordinate"),
};
Ok(Coord {
x: x,
y: y,
z: None,
m: None,
})
}
}
#[cfg(test)]
mod tests {
use super::Coord;
#[test]
fn write_2d_coord() {
let coord = Coord {
x: 10.1,
y: 20.2,
z: None,
m: None,
};
assert_eq!("10.1 20.2", format!("{}", coord));
}
#[test]
fn write_3d_coord() {
let coord = Coord {
x: 10.1,
y: 20.2,
z: Some(-30.3),
m: None,
};
assert_eq!("10.1 20.2 -30.3", format!("{}", coord));
}
#[test]
fn write_2d_coord_with_linear_referencing_system() {
let coord = Coord {
x: 10.1,
y: 20.2,
z: None,
m: Some(10.),
};
assert_eq!("10.1 20.2 10", format!("{}", coord));
}
#[test]
fn write_3d_coord_with_linear_referencing_system() {
let coord = Coord {
x: 10.1,
y: 20.2,
z: Some(-30.3),
m: Some(10.),
};
assert_eq!("10.1 20.2 -30.3 10", format!("{}", coord));
}
}