openbirch-rs/src/lib/node/call.rs

117 lines
3.4 KiB
Rust

use std::rc::Rc;
use crate::{
environment::Environment,
node::{closure::Closure, function::FunctionType},
};
use super::{Error, Node, NodeEnum, Precedence};
#[derive(Debug, Clone, PartialEq, PartialOrd)]
pub struct Call {
function: Rc<NodeEnum>,
arguments: Vec<Rc<NodeEnum>>,
}
impl Node for Call {
fn evaluate(&self, env: &mut Environment) -> Result<Rc<NodeEnum>, Error> {
if env.closures_enabled() {
return Ok(Rc::new(self.clone().into()));
}
// Evaluate callee and error if its not a function
let evaluated = self.function.evaluate(env)?;
// let func = if let NodeEnum::Function(func) = evaluated.as_ref() {
// func
// } else {
// return Ok(Rc::new(self.clone().into()));
// };
env.push_stack()?;
let func = match evaluated.as_ref() {
NodeEnum::Function(func) => func,
NodeEnum::Closure(closure) => {
for (k, v) in closure.get_captured_variables() {
env.insert(*k, v.clone(), false);
}
closure.get_function()
}
_ => {
return Ok(Rc::new(self.clone().into()));
}
};
let arguments = {
let mut arguments = vec![];
for value in self.arguments.iter() {
arguments.push(value.evaluate(env)?);
}
arguments
};
// Call function body with arguments
let ret = match func.get_body() {
// Pass arguments to native function
FunctionType::Native(_name, native_function) => native_function(&arguments, env),
FunctionType::UserFunction(body, fargs) => {
if fargs.len() != arguments.len() {
return Err(Error::ArgumentCount(fargs.len(), arguments.len()));
}
// Define variables
fargs.iter().zip(&arguments).for_each(|(symbol, value)| {
env.insert(symbol.get_value(), value.clone(), false);
});
let ev = body.evaluate(env);
if ev.is_err() {
env.pop_stack()?;
return ev;
}
let ev = ev?;
// Return evaluated return value for function
Ok(match ev.as_ref() {
NodeEnum::Function(hof) => {
let captures = fargs.iter().map(|a| a.get_value()).zip(arguments).collect();
Closure::new(hof.clone(), captures)
}
_ => ev,
})
}
};
env.pop_stack()?;
ret
}
fn as_string(&self, env: Option<&Environment>) -> String {
let arguments = format!(
"{}",
self.arguments
.iter()
.map(|x| x.as_string(env))
.reduce(|a, b| a + ", " + &b)
.unwrap_or("".to_owned())
);
format!("{}({})", self.function.as_string(env), arguments)
}
fn precedence(&self) -> Precedence {
Precedence::Call
}
}
impl Call {
pub fn new(function: Rc<NodeEnum>, arguments: Vec<Rc<NodeEnum>>) -> Rc<NodeEnum> {
Rc::new(
Self {
function,
arguments,
}
.into(),
)
}
}