Struct Env 

pub struct Env { /* private fields */ }

The names a running program can reach: the values it has assigned, the verbs it has named, and the arguments bound to its parameters.

An explicit definition runs with a frame of its own on top: J’s =. writes there and =: writes to the globals, and a name is looked for in the frame before the globals. Frames do not nest — a definition called from another sees only its own locals, which is what both references do.

Implementations

impl Env

pub fn new(args: Vec<Array>) -> Env

pub fn get(&self, name: &str) -> Option<Array>

pub fn assign(&mut self, name: String, value: Array, scope: Scope)

pub fn define(&mut self, name: String, verb: Verb)

pub fn undefine(&mut self, name: &str)

pub fn verb(&self, name: &str) -> Option<&Verb>

pub fn arg(&self, i: usize) -> Result<Array>

pub fn enter( &mut self, frame: HashMap<String, Array>, def: Arc<ExplicitDef>, span: Span, ) -> Result<()>

Start a definition’s frame. Fails rather than overflowing the stack.

pub fn leave(&mut self) -> HashMap<String, Array>

End a definition’s frame and hand back the names it assigned.

pub fn current_def(&self) -> Option<Arc<ExplicitDef>>

The innermost definition now running; $: and ∇ name it.