use builtin_macros::builtins; use smol_str::SmolStr; use std::{ env, time::{SystemTime, UNIX_EPOCH}, }; use crate::{ errors::ErrorKind, io::FileType, value::{NixAttrs, Thunk}, vm::VM, Value, }; #[builtins] mod impure_builtins { use super::*; use crate::builtins::coerce_value_to_path; #[builtin("getEnv")] fn builtin_get_env(_: &mut VM, var: Value) -> Result { Ok(env::var(var.to_str()?).unwrap_or_else(|_| "".into()).into()) } #[builtin("pathExists")] fn builtin_path_exists(vm: &mut VM, s: Value) -> Result { let path = coerce_value_to_path(&s, vm)?; vm.io().path_exists(path).map(Value::Bool) } #[builtin("readDir")] fn builtin_read_dir(vm: &mut VM, path: Value) -> Result { let path = coerce_value_to_path(&path, vm)?; let res = vm.io().read_dir(path)?.into_iter().map(|(name, ftype)| { ( name, Value::String( SmolStr::new(match ftype { FileType::Directory => "directory", FileType::Regular => "regular", FileType::Symlink => "symlink", FileType::Unknown => "unknown", }) .into(), ), ) }); Ok(Value::attrs(NixAttrs::from_iter(res))) } #[builtin("readFile")] fn builtin_read_file(vm: &mut VM, path: Value) -> Result { let path = coerce_value_to_path(&path, vm)?; vm.io() .read_to_string(path) .map(|s| Value::String(s.into())) } } /// Return all impure builtins, that is all builtins which may perform I/O /// outside of the VM and so cannot be used in all contexts (e.g. WASM). pub fn impure_builtins() -> Vec<(&'static str, Value)> { let mut result = impure_builtins::builtins(); // currentTime pins the time at which evaluation was started { let seconds = match SystemTime::now().duration_since(UNIX_EPOCH) { Ok(dur) => dur.as_secs() as i64, // This case is hit if the system time is *before* epoch. Err(err) => -(err.duration().as_secs() as i64), }; result.push(("currentTime", Value::Integer(seconds))); } result }