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Declare forms ​

This page refers to top-level declare forms, which are defined at the top level of the file. For function-level declare forms, see 1. Annotating code.

Top-level declare forms can be defined in one of two ways.
Without any dependencies:

emacs-lisp
(declare
 (et (@declare-form-1 ...)
     (@declare-form-2 ...)))

With et-annotate as a dependency:

emacs-lisp
(et-declare
 (@declare-form-1 ...)
 (@declare-form-2 ...))

@def ​

Declare a function's type.

emacs-lisp
(et-declare
 (@def my-fn (param1: Type1 param2: Type2) ReturnType)
 ;; With generics
 (@def my-generic-fn ([T (N <: Number)] obj: T nums: List<N>) Alist<N_T>)
 ;; With inline generics
 (@def my-inline-generic-fn (obj: [T] nums: [N <: Number]) Alist<N_T>))

@check ​

Declare a checker for a macro.

emacs-lisp
(et-declare
  ;; A macro which can be type-checked by simply expanding it
  (@check my-simple-macro ($expand))
  ;; A macro which takes a string argument, and the rest is the body
  (@check my-with-default-directory ($body String))
  ;; Type check this macro by checking some other equivalent expression
  (@check my-increment ($arglist (p) ($exp `(setf ,p (1+ ,p))))))

@variable ​

Declare a variable's type.

emacs-lisp
(et-declare
 (@variable my-variable Type))

@alias ​

Define an alias.

emacs-lisp
(et-declare
 (@alias MyIntList List<Integer>)
 ;; With a type parameter
 (@alias MySymbolAlist [V] Alist<Symbol_V>)
 ;; With a default value for a type parameter
 (@alias MyOtherAlist [K (V = Any)] Alist<K_V>)
 ;; With a constraint and a default value on the same type parameter
 (@alias MyNumberAlist [K (V <: Number) (V = Integer)] Alist<K_V>))

@syntax ​

Define a type macro.

emacs-lisp
(et-declare
 (@syntax my-cons (&optional arg1 arg2)
          `(Cons ,(or arg1 'Any) ,(or arg2 arg1 'Any))))

@symbol-property ​

To get accurate types for put and get, you can declare a particular symbol-property to have a particular type.

emacs-lisp
(et-declare
 (@symbol-property my-documentation String))

(get SYMBOL 'foo)
;; >> Any
(get SYMBOL 'my-documentation)
;; >> String?

@eval ​

Run some elisp code within the checker process.

emacs-lisp
(et-declare
 (@eval (setq et-allow-unrecognized nil)))

;; et will complain about this unrecognized top-level form
(my-unrecognized-function)