typst/src/library/utility.rs

84 lines
2.6 KiB
Rust

use std::cmp::Ordering;
use std::str::FromStr;
use crate::color::{Color, RgbaColor};
use crate::pretty::pretty;
use super::*;
/// `type`: The name of a value's type.
pub fn type_(_: &mut EvalContext, args: &mut FuncArgs) -> TypResult<Value> {
let value = args.expect::<Value>("value")?;
Ok(value.type_name().into())
}
/// `repr`: The string representation of a value.
pub fn repr(_: &mut EvalContext, args: &mut FuncArgs) -> TypResult<Value> {
let value = args.expect::<Value>("value")?;
Ok(pretty(&value).into())
}
/// `len`: The length of a string, an array or a dictionary.
pub fn len(_: &mut EvalContext, args: &mut FuncArgs) -> TypResult<Value> {
let Spanned { v, span } = args.expect("collection")?;
Ok(match v {
Value::Str(v) => Value::Int(v.len() as i64),
Value::Array(v) => Value::Int(v.len()),
Value::Dict(v) => Value::Int(v.len()),
_ => bail!(span, "expected string, array or dictionary"),
})
}
/// `rgb`: Create an RGB(A) color.
pub fn rgb(_: &mut EvalContext, args: &mut FuncArgs) -> TypResult<Value> {
Ok(Value::Color(Color::Rgba(
if let Some(string) = args.eat::<Spanned<EcoString>>() {
match RgbaColor::from_str(&string.v) {
Ok(color) => color,
Err(_) => bail!(string.span, "invalid color"),
}
} else {
let r = args.expect("red component")?;
let g = args.expect("green component")?;
let b = args.expect("blue component")?;
let a = args.eat().unwrap_or(1.0);
let f = |v: f64| (v.clamp(0.0, 1.0) * 255.0).round() as u8;
RgbaColor::new(f(r), f(g), f(b), f(a))
},
)))
}
/// `min`: The minimum of a sequence of values.
pub fn min(_: &mut EvalContext, args: &mut FuncArgs) -> TypResult<Value> {
minmax(args, Ordering::Less)
}
/// `max`: The maximum of a sequence of values.
pub fn max(_: &mut EvalContext, args: &mut FuncArgs) -> TypResult<Value> {
minmax(args, Ordering::Greater)
}
/// Find the minimum or maximum of a sequence of values.
fn minmax(args: &mut FuncArgs, goal: Ordering) -> TypResult<Value> {
let span = args.span;
let mut extremum = args.expect::<Value>("value")?;
for value in args.all::<Value>() {
match value.partial_cmp(&extremum) {
Some(ordering) => {
if ordering == goal {
extremum = value;
}
}
None => bail!(
span,
"cannot compare {} with {}",
extremum.type_name(),
value.type_name(),
),
}
}
Ok(extremum)
}