ksl 0.1.30

KSL core library and interpreter
Documentation
//! # ksl::builtin::parse_number
//!
//! Built-in function `ParseNumber`.

use crate::{Environment, eval::apply::eval_apply, value::Value};

pub(crate) fn builtin(args: &[Value], env: Environment) -> Result<Value, std::sync::Arc<str>> {
    if let [val] = args {
        match eval_apply(val, env)? {
            Value::String(s) => s.trim().parse::<f64>().map(Value::Number).map_err(|_| {
                std::sync::Arc::from(format!(
                    concat!(
                        "Error[ksl::builtin::ParseNumber]: ",
                        "`{}` is not a valid number string."
                    ),
                    s
                ))
            }),

            e => Err(std::sync::Arc::from(format!(
                concat!(
                    "Error[ksl::builtin::ParseNumber]: ",
                    "Expected a number string, but got: `{}`."
                ),
                e
            ))),
        }
    } else {
        Err(std::sync::Arc::from(format!(
            concat!(
                "Error[ksl::builtin::ParseNumber]: ",
                "Expected 1 parameter, but {} were passed."
            ),
            args.len()
        )))
    }
}