elisp: Evaluation Notation
1.3.3 Evaluation Notation
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A Lisp expression that you can evaluate is called a “form”. Evaluating
a form always produces a result, which is a Lisp object. In the
examples in this manual, this is indicated with ‘⇒’:
(car '(1 2))
⇒ 1
You can read this as “‘(car '(1 2))’ evaluates to 1”.
When a form is a macro call, it expands into a new form for Lisp to
evaluate. We show the result of the expansion with ‘↦’. We may or may
not show the result of the evaluation of the expanded form.
(third '(a b c))
↦ (car (cdr (cdr '(a b c))))
⇒ c
To help describe one form, we sometimes show another form that
produces identical results. The exact equivalence of two forms is
indicated with ‘≡’.
(make-sparse-keymap) ≡ (list 'keymap)
Info Catalog
elisp: nil and t
elisp: Conventions
elisp: Printing Notation