grass/src/builtin/math.rs
2020-04-05 18:30:17 -04:00

130 lines
4.6 KiB
Rust

use std::collections::HashMap;
#[cfg(feature = "random")]
use num_traits::{One, Signed, ToPrimitive, Zero};
#[cfg(feature = "random")]
use rand::Rng;
use super::Builtin;
use crate::unit::Unit;
use crate::value::{Number, Value};
pub(crate) fn register(f: &mut HashMap<String, Builtin>) {
f.insert(
"percentage".to_owned(),
Builtin::new(|mut args, scope, super_selector| {
max_args!(args, 1);
let num = match arg!(args, scope, super_selector, 0, "number") {
Value::Dimension(n, Unit::None) => n * Number::from(100),
v @ Value::Dimension(..) => {
return Err(format!("$number: Expected {} to have no units.", v).into())
}
v => return Err(format!("$number: {} is not a number.", v).into()),
};
Ok(Value::Dimension(num, Unit::Percent))
}),
);
f.insert(
"round".to_owned(),
Builtin::new(|mut args, scope, super_selector| {
max_args!(args, 1);
match arg!(args, scope, super_selector, 0, "number") {
Value::Dimension(n, u) => Ok(Value::Dimension(n.round(), u)),
v => Err(format!("$number: {} is not a number.", v).into()),
}
}),
);
f.insert(
"ceil".to_owned(),
Builtin::new(|mut args, scope, super_selector| {
max_args!(args, 1);
match arg!(args, scope, super_selector, 0, "number") {
Value::Dimension(n, u) => Ok(Value::Dimension(n.ceil(), u)),
v => Err(format!("$number: {} is not a number.", v).into()),
}
}),
);
f.insert(
"floor".to_owned(),
Builtin::new(|mut args, scope, super_selector| {
max_args!(args, 1);
match arg!(args, scope, super_selector, 0, "number") {
Value::Dimension(n, u) => Ok(Value::Dimension(n.floor(), u)),
v => Err(format!("$number: {} is not a number.", v).into()),
}
}),
);
f.insert(
"abs".to_owned(),
Builtin::new(|mut args, scope, super_selector| {
max_args!(args, 1);
match arg!(args, scope, super_selector, 0, "number") {
Value::Dimension(n, u) => Ok(Value::Dimension(n.abs(), u)),
v => Err(format!("$number: {} is not a number.", v).into()),
}
}),
);
f.insert(
"comparable".to_owned(),
Builtin::new(|mut args, scope, super_selector| {
max_args!(args, 2);
let unit1 = match arg!(args, scope, super_selector, 0, "number1") {
Value::Dimension(_, u) => u,
v => return Err(format!("$number1: {} is not a number.", v).into()),
};
let unit2 = match arg!(args, scope, super_selector, 1, "number2") {
Value::Dimension(_, u) => u,
v => return Err(format!("$number2: {} is not a number.", v).into()),
};
Ok(Value::bool(unit1.comparable(&unit2)))
}),
);
// TODO: write tests for this. how?
#[cfg(feature = "random")]
f.insert(
"random".to_owned(),
Builtin::new(|mut args, scope, super_selector| {
max_args!(args, 1);
let limit = match arg!(args, scope, super_selector, 0, "limit" = Value::Null) {
Value::Dimension(n, _) => n,
Value::Null => {
let mut rng = rand::thread_rng();
return Ok(Value::Dimension(
Number::from(rng.gen_range(0.0, 1.0)),
Unit::None,
));
}
v => return Err(format!("$limit: {} is not a number.", v).into()),
};
if limit.is_one() {
return Ok(Value::Dimension(Number::one(), Unit::None));
}
if limit.is_decimal() {
return Err(format!("$limit: {} is not an int.", limit).into());
}
if limit.is_zero() || limit.is_negative() {
return Err(format!("$limit: Must be greater than 0, was {}.", limit).into());
}
let limit = match limit.to_integer().to_u32() {
Some(n) => n,
None => {
return Err(
format!("max must be in range 0 < max ≤ 2^32, was {}", limit).into(),
)
}
};
let mut rng = rand::thread_rng();
Ok(Value::Dimension(
Number::from(rng.gen_range(0, limit) + 1),
Unit::None,
))
}),
);
}