Major Section: SWITCHES-PARAMETERS-AND-MODES
Example: (table macro-aliases-table 'append 'binary-append)This example associates the function symbol
binary-appendwith the macro name
append. As a result, the name
appendmay be used as a runic designator (see theories) by the various theory functions. Thus, for example, it will be legal to write
(in-theory (disable append))as an abbreviation for
(in-theory (disable binary-append))which in turn really abbreviates
(in-theory (set-difference-theories (current-theory :here) '(binary-append))) General Form: (table macro-aliases-table 'macro-name 'function-name)or very generally
(table macro-aliases-table macro-name-form function-name-form)where
function-name-formevaluate, respectively, to a macro name and a symbol in the current ACL2 world. See table for a general discussion of tables and the
tableevent used to manipulate tables.
function-name-form (above) does not need to evaluate to a
function symbol, but only to a symbol. As a result, one can introduce the
alias before defining a recursive function, as follows.
(table macro-aliases-table 'mac 'fn) (defun fn (x) (if (consp x) (mac (cdr x)) x))Although this is obviously contrived example, this flexibility can be useful to macro writers; see for example the definition of ACL2 system macro
macro-aliases-table is an alist that associates
macro symbols with function symbols, so that macro names may be used
as runic designators (see theories). For a convenient way to
add entries to this table, see add-macro-alias. To remove
entries from the table with ease, see remove-macro-alias.
This table is used by the theory functions. For example, in order
(disable append) be interpreted as
it is necessary that the example form above has been executed. In
fact, this table does indeed associate many of the macros provided
by the ACL2 system, including
append, with function symbols.
Loosely speaking, it only does so when the macro is ``essentially
the same thing as'' a corresponding function; for example,
(append x y) and
(binary-append x y) represent the same term,
for any expressions