diff options
Diffstat (limited to 'tvix/eval/src/lib.rs')
| -rw-r--r-- | tvix/eval/src/lib.rs | 259 |
1 files changed, 202 insertions, 57 deletions
diff --git a/tvix/eval/src/lib.rs b/tvix/eval/src/lib.rs index 97690d13610e..bfdd30154acf 100644 --- a/tvix/eval/src/lib.rs +++ b/tvix/eval/src/lib.rs @@ -64,6 +64,192 @@ pub use crate::value::{Builtin, CoercionKind, NixAttrs, NixList, NixString, Valu #[cfg(feature = "impure")] pub use crate::io::StdIO; +/// Builder for building an [`Evaluation`]. +/// +/// Construct an [`EvaluationBuilder`] by calling one of: +/// +/// - [`Evaluation::builder`] / [`EvaluationBuilder::new`] +/// - [`Evaluation::builder_impure`] [`EvaluationBuilder::new_impure`] +/// - [`Evaluation::builder_pure`] [`EvaluationBuilder::new_pure`] +/// +/// Then configure the fields by calling the various methods on [`EvaluationBuilder`], and finally +/// call [`build`](Self::build) to construct an [`Evaluation`] +pub struct EvaluationBuilder<'co, 'ro, 'env, IO> { + source_map: SourceCode, + builtins: Vec<(&'static str, Value)>, + src_builtins: Vec<(&'static str, &'static str)>, + env: Option<&'env HashMap<SmolStr, Value>>, + io_handle: IO, + enable_import: bool, + strict: bool, + nix_path: Option<String>, + compiler_observer: Option<&'co mut dyn CompilerObserver>, + runtime_observer: Option<&'ro mut dyn RuntimeObserver>, +} + +// NOTE(aspen): The methods here are intentionally incomplete; feel free to add new ones (ideally +// with similar naming conventions to the ones already present) but don't expose fields publically! +impl<'co, 'ro, 'env, IO> EvaluationBuilder<'co, 'ro, 'env, IO> { + pub fn new(io_handle: IO) -> Self { + let mut builtins = builtins::pure_builtins(); + builtins.extend(builtins::placeholders()); // these are temporary + + Self { + source_map: SourceCode::default(), + enable_import: false, + io_handle, + builtins, + src_builtins: vec![], + env: None, + strict: false, + nix_path: None, + compiler_observer: None, + runtime_observer: None, + } + } + + pub fn build(self) -> Evaluation<'co, 'ro, 'env, IO> { + Evaluation { + source_map: self.source_map, + builtins: self.builtins, + src_builtins: self.src_builtins, + env: self.env, + io_handle: self.io_handle, + enable_import: self.enable_import, + strict: self.strict, + nix_path: self.nix_path, + compiler_observer: self.compiler_observer, + runtime_observer: self.runtime_observer, + } + } + + pub fn io_handle<IO2>(self, io_handle: IO2) -> EvaluationBuilder<'co, 'ro, 'env, IO2> { + EvaluationBuilder { + io_handle, + source_map: self.source_map, + builtins: self.builtins, + src_builtins: self.src_builtins, + env: self.env, + enable_import: self.enable_import, + strict: self.strict, + nix_path: self.nix_path, + compiler_observer: self.compiler_observer, + runtime_observer: self.runtime_observer, + } + } + + pub fn with_enable_import(self, enable_import: bool) -> Self { + Self { + enable_import, + ..self + } + } + + pub fn disable_import(self) -> Self { + self.with_enable_import(false) + } + + pub fn enable_import(self) -> Self { + self.with_enable_import(true) + } + + pub fn add_builtins<I>(mut self, builtins: I) -> Self + where + I: IntoIterator<Item = (&'static str, Value)>, + { + self.builtins.extend(builtins); + self + } + + pub fn with_strict(self, strict: bool) -> Self { + Self { strict, ..self } + } + + pub fn strict(self) -> Self { + self.with_strict(true) + } + + pub fn add_src_builtin(mut self, name: &'static str, src: &'static str) -> Self { + self.src_builtins.push((name, src)); + self + } + + pub fn nix_path(self, nix_path: Option<String>) -> Self { + Self { nix_path, ..self } + } + + pub fn env(self, env: Option<&'env HashMap<SmolStr, Value>>) -> Self { + Self { env, ..self } + } + + pub fn compiler_observer( + self, + compiler_observer: Option<&'co mut dyn CompilerObserver>, + ) -> Self { + Self { + compiler_observer, + ..self + } + } + + pub fn set_compiler_observer( + &mut self, + compiler_observer: Option<&'co mut dyn CompilerObserver>, + ) { + self.compiler_observer = compiler_observer; + } + + pub fn runtime_observer(self, runtime_observer: Option<&'ro mut dyn RuntimeObserver>) -> Self { + Self { + runtime_observer, + ..self + } + } + + pub fn set_runtime_observer(&mut self, runtime_observer: Option<&'ro mut dyn RuntimeObserver>) { + self.runtime_observer = runtime_observer; + } +} + +impl<'co, 'ro, 'env, IO> EvaluationBuilder<'co, 'ro, 'env, IO> { + pub fn source_map(&self) -> &SourceCode { + &self.source_map + } +} + +impl<'co, 'ro, 'env> EvaluationBuilder<'co, 'ro, 'env, Box<dyn EvalIO>> { + /// Initialize an `Evaluation`, without the import statement available, and + /// all IO operations stubbed out. + pub fn new_pure() -> Self { + Self::new(Box::new(DummyIO) as Box<dyn EvalIO>).with_enable_import(false) + } + + #[cfg(feature = "impure")] + /// Configure an `Evaluation` to have impure features available + /// with the given I/O implementation. + /// + /// If no I/O implementation is supplied, [`StdIO`] is used by + /// default. + pub fn enable_impure(mut self, io: Option<Box<dyn EvalIO>>) -> Self { + self.io_handle = io.unwrap_or_else(|| Box::new(StdIO) as Box<dyn EvalIO>); + self.enable_import = true; + self.builtins.extend(builtins::impure_builtins()); + + // Make `NIX_PATH` resolutions work by default, unless the + // user already overrode this with something else. + if self.nix_path.is_none() { + self.nix_path = std::env::var("NIX_PATH").ok(); + } + self + } + + #[cfg(feature = "impure")] + /// Initialise an `Evaluation`, with all impure features turned on by default. + pub fn new_impure() -> Self { + Self::new_pure().enable_impure(None) + } +} + /// An `Evaluation` represents how a piece of Nix code is evaluated. It can be /// instantiated and configured directly, or it can be accessed through the /// various simplified helper methods available below. @@ -79,42 +265,42 @@ pub struct Evaluation<'co, 'ro, 'env, IO> { /// /// This defaults to all pure builtins. Users might want to add /// the set of impure builtins, or other custom builtins. - pub builtins: Vec<(&'static str, Value)>, + builtins: Vec<(&'static str, Value)>, /// Set of builtins that are implemented in Nix itself and should /// be compiled and inserted in the builtins set. - pub src_builtins: Vec<(&'static str, &'static str)>, + src_builtins: Vec<(&'static str, &'static str)>, /// Top-level variables to define in the evaluation - pub env: Option<&'env HashMap<SmolStr, Value>>, + env: Option<&'env HashMap<SmolStr, Value>>, /// Implementation of file-IO to use during evaluation, e.g. for /// impure builtins. /// /// Defaults to [`DummyIO`] if not set explicitly. - pub io_handle: IO, + io_handle: IO, /// Determines whether the `import` builtin should be made /// available. Note that this depends on the `io_handle` being /// able to read the files specified as arguments to `import`. - pub enable_import: bool, + enable_import: bool, /// Determines whether the returned value should be strictly /// evaluated, that is whether its list and attribute set elements /// should be forced recursively. - pub strict: bool, + strict: bool, /// (optional) Nix search path, e.g. the value of `NIX_PATH` used /// for resolving items on the search path (such as `<nixpkgs>`). - pub nix_path: Option<String>, + nix_path: Option<String>, /// (optional) compiler observer for reporting on compilation /// details, like the emitted bytecode. - pub compiler_observer: Option<&'co mut dyn CompilerObserver>, + compiler_observer: Option<&'co mut dyn CompilerObserver>, /// (optional) runtime observer, for reporting on execution steps /// of Nix code. - pub runtime_observer: Option<&'ro mut dyn RuntimeObserver>, + runtime_observer: Option<&'ro mut dyn RuntimeObserver>, } /// Result of evaluating a piece of Nix code. If evaluation succeeded, a value @@ -136,61 +322,20 @@ pub struct EvaluationResult { pub expr: Option<rnix::ast::Expr>, } -impl<'co, 'ro, 'env, IO> Evaluation<'co, 'ro, 'env, IO> -where - IO: AsRef<dyn EvalIO> + 'static, -{ - /// Initialize an `Evaluation`. - pub fn new(io_handle: IO, enable_import: bool) -> Self { - let mut builtins = builtins::pure_builtins(); - builtins.extend(builtins::placeholders()); // these are temporary - - Self { - source_map: SourceCode::default(), - enable_import, - io_handle, - builtins, - src_builtins: vec![], - env: None, - strict: false, - nix_path: None, - compiler_observer: None, - runtime_observer: None, - } +impl<'co, 'ro, 'env, IO> Evaluation<'co, 'ro, 'env, IO> { + pub fn builder(io_handle: IO) -> EvaluationBuilder<'co, 'ro, 'env, IO> { + EvaluationBuilder::new(io_handle) } } impl<'co, 'ro, 'env> Evaluation<'co, 'ro, 'env, Box<dyn EvalIO>> { - /// Initialize an `Evaluation`, without the import statement available, and - /// all IO operations stubbed out. - pub fn new_pure() -> Self { - Self::new(Box::new(DummyIO) as Box<dyn EvalIO>, false) - } - #[cfg(feature = "impure")] - /// Configure an `Evaluation` to have impure features available - /// with the given I/O implementation. - /// - /// If no I/O implementation is supplied, [`StdIO`] is used by - /// default. - pub fn enable_impure(&mut self, io: Option<Box<dyn EvalIO>>) { - self.io_handle = io.unwrap_or_else(|| Box::new(StdIO) as Box<dyn EvalIO>); - self.enable_import = true; - self.builtins.extend(builtins::impure_builtins()); - - // Make `NIX_PATH` resolutions work by default, unless the - // user already overrode this with something else. - if self.nix_path.is_none() { - self.nix_path = std::env::var("NIX_PATH").ok(); - } + pub fn builder_impure() -> EvaluationBuilder<'co, 'ro, 'env, Box<dyn EvalIO>> { + EvaluationBuilder::new_impure() } - #[cfg(feature = "impure")] - /// Initialise an `Evaluation`, with all impure features turned on by default. - pub fn new_impure() -> Self { - let mut eval = Self::new_pure(); - eval.enable_impure(None); - eval + pub fn builder_pure() -> EvaluationBuilder<'co, 'ro, 'env, Box<dyn EvalIO>> { + EvaluationBuilder::new_pure() } } |