Struct EvalStateBuilder 

pub struct EvalStateBuilder { /* private fields */ }

Builder for configuring and creating an EvalState.

Provides advanced configuration options for evaluation context setup. Use EvalState::new for simple cases or this builder for custom configuration.

Requires Nix 2.26.0 or later.

Examples

let store = Store::open(None, HashMap::new())?;

let mut es: EvalState = EvalStateBuilder::new(store)?
    .lookup_path(["nixpkgs=/path/to/nixpkgs", "home-manager=/path/to/hm"])?
    .build()?;

let value = es.eval_from_string("<nixpkgs>", /* path display: */ "in-memory")?;

Implementations

impl EvalStateBuilder

pub fn new(store: Store) -> Result<EvalStateBuilder>

Creates a new EvalStateBuilder.

pub fn lookup_path<'a>( self, path: impl IntoIterator<Item = &'a str>, ) -> Result<Self>

Sets the lookup path for Nix expression evaluation.

pub fn load_ambient_settings(self, load: bool) -> Self

Sets whether to load settings from the ambient environment.

When enabled (default), calls nix_eval_state_builder_load to load settings from NIX_CONFIG and other environment variables. When disabled, only the explicitly configured settings are used.

pub fn build(&self) -> Result<EvalState>

Builds the configured EvalState.

pub fn raw_ptr(&self) -> *mut eval_state_builder

Returns a raw pointer to the underlying eval state builder.

Safety

The caller must ensure that the pointer is not used beyond the lifetime of this builder.

Trait Implementations

impl Drop for EvalStateBuilder

Available on nix_at_least=2.26 only.

fn drop(&mut self)

Executes the destructor for this type.