pipa-lang 1.0.0-alpha.1

A tiny template language
Documentation 
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// SPDX-FileCopyrightText: Copyright 2026 olav@occy.org
// SPDX-License-Identifier: MPL-2.0

use crate::lang::adapter::Adapter;
use crate::lang::args::eval_unary_arg;
use crate::lang::arity::Arity;
use crate::lang::arity::assert_func_arity;
use crate::lang::error::Error;
use crate::lang::machine::Machine;
use crate::lang::node::Node;
use crate::value::Value;

pub(crate) fn not(
    adapter: &impl Adapter,
    machine: &mut Machine<'_>,
    stdin: Option<&Value>,
    node: Node,
) -> Result<Value, Error> {
    assert_func_arity(adapter, machine, stdin, &node, &Arity::new(1))?;

    Ok(match eval_unary_arg(adapter, machine, stdin, node)? {
        Some(v) if !v.is_empty() => falsy(),
        Some(v) => v.with_data(truthy()),
        _ => truthy(),
    })
}

fn truthy() -> Value {
    Value::from("true")
}

fn falsy() -> Value {
    Value::default()
}