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// usage: cargo run --release --example compile
use std::collections::BTreeMap;
use fasteval::Evaler; // use this trait so we can call eval().
use fasteval::Compiler; // use this trait so we can call compile().
fn main() -> Result<(), fasteval::Error> {
let parser = fasteval::Parser::new();
let mut slab = fasteval::Slab::new();
let mut map = BTreeMap::new();
let expr_str = "sin(deg/360 * 2*pi())";
let compiled = parser.parse(expr_str, &mut slab.ps)?.from(&slab.ps).compile(&slab.ps, &mut slab.cs);
for deg in 0..360 {
map.insert("deg".to_string(), deg as f64);
// When working with compiled constant expressions, you can use the
// eval_compiled*!() macros to save a function call:
let val = fasteval::eval_compiled!(compiled, &slab, &mut map);
eprintln!("sin({}°) = {}", deg, val);
}
Ok(())
}
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