Module ir 

The language-agnostic program representation and its evaluator.

Structs

Branch

One arm of an if. or select.: a test (absent for the default arm) and the body to run when it holds.

ExplicitDef

An explicit definition: J’s 3 : '…', 4 : '…' and {{ … }}, APL’s {…} and ∇-defined functions.

ParamSpec

Program

A compiled program: immutable, reusable, holds no data bindings.

Enums

Control

A control-flow sentence. Every body is a block: a list of sentences whose value is the last one’s.

Expr

Scope

Where an assignment puts its name. The two differ only inside an explicit definition, which is the only thing that has a local frame.

Constants

NILADIC

The right-argument name a NILADIC APL definition carries. No sentence can write it, so the body cannot read the argument it never gets, and a definition wearing it is called by naming it rather than applying it.