Bindat: Document sint; add le arg to uint; deprecate uintr

* lisp/emacs-lisp/bindat.el (bindat--type) <uint>: Add `le` optional arg.
(bindat--type) <uintr>: Delete method.
(uintr): Re-define as a bindat-macro instead.
(bindat-type): Update docstring accordingly.
(bindat--primitives): Update.
(sint): Simplify.

* doc/lispref/processes.texi (Bindat Types): Update `uint`, add `sint`,
and remove `uintr`.

* test/lisp/emacs-lisp/bindat-tests.el (data-bindat-spec): Use the new
`le` arg of `uint` instead of `uintr`.
This commit is contained in:
Stefan Monnier 2022-06-11 11:55:27 -04:00
parent b591a041e3
commit 51def94e9c
3 changed files with 33 additions and 33 deletions

View file

@ -3470,13 +3470,15 @@ type values:
@itemx byte
Unsigned byte, with length 1.
@item uint @var{bitlen}
Unsigned integer in network byte order, with @var{bitlen} bits.
@item uint @var{bitlen} &optional @var{le}
Unsigned integer in network byte order (big-endian), with @var{bitlen} bits.
@var{bitlen} has to be a multiple of 8.
If @var{le} is non-@code{nil}, then use little-endian byte order.
@item uintr @var{bitlen}
Unsigned integer in little endian order, with @var{bitlen} bits.
@item sint @var{bitlen} @var{le}
Signed integer in network byte order (big-endian), with @var{bitlen} bits.
@var{bitlen} has to be a multiple of 8.
If @var{le} is non-@code{nil}, then use little-endian byte order.
@item str @var{len}
Unibyte string (@pxref{Text Representations}) of length @var{len} bytes.

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@ -77,7 +77,7 @@
;; (bindat-type
;; (type u8)
;; (opcode u8)
;; (length uintr 32) ;; little endian order
;; (length uint 32 t) ;; little endian order
;; (id strz 8)
;; (data vec length)
;; (_ align 4)))
@ -663,19 +663,15 @@ is the name of a variable that will hold the value we need to pack.")
(`(length . ,_) `(cl-incf bindat-idx 1))
(`(pack . ,args) `(bindat--pack-u8 . ,args))))
(cl-defmethod bindat--type (op (_ (eql 'uint)) n)
(cl-defmethod bindat--type (op (_ (eql 'uint)) n &optional le)
(if (eq n 8) (bindat--type op 'byte)
(bindat--pcase op
('unpack `(bindat--unpack-uint ,n))
('unpack
`(if ,le (bindat--unpack-uintr ,n) (bindat--unpack-uint ,n)))
(`(length . ,_) `(cl-incf bindat-idx (/ ,n 8)))
(`(pack . ,args) `(bindat--pack-uint ,n . ,args)))))
(cl-defmethod bindat--type (op (_ (eql 'uintr)) n)
(if (eq n 8) (bindat--type op 'byte)
(bindat--pcase op
('unpack `(bindat--unpack-uintr ,n))
(`(length . ,_) `(cl-incf bindat-idx (/ ,n 8)))
(`(pack . ,args) `(bindat--pack-uintr ,n . ,args)))))
(`(pack . ,args)
`(if ,le (bindat--pack-uintr ,n . ,args)
(bindat--pack-uint ,n . ,args))))))
(cl-defmethod bindat--type (op (_ (eql 'str)) len)
(bindat--pcase op
@ -829,7 +825,7 @@ is the name of a variable that will hold the value we need to pack.")
&optional ":unpack-val" def-form))
(def-edebug-elem-spec 'bindat-type
'(&or ["uint" def-form]
'(&or ["uint" def-form &optional def-form]
["uintr" def-form]
["str" def-form]
["strz" &optional def-form]
@ -849,8 +845,7 @@ is the name of a variable that will hold the value we need to pack.")
"Return the Bindat type value to pack&unpack TYPE.
TYPE is a Bindat type expression. It can take the following forms:
uint BITLEN - Big-endian unsigned integer
uintr BITLEN - Little-endian unsigned integer
uint BITLEN [LE] - unsigned integer (big-endian if LE is nil)
str LEN - Byte string
strz [LEN] - Zero-terminated byte-string
bits LEN - Bit vector (LEN is counted in bytes)
@ -877,7 +872,7 @@ controlled in the following way:
- If the list of fields is preceded with `:pack-var VAR' then the object to
be packed is bound to VAR when evaluating the EXPs of `:pack-val'.
All the above BITLEN, LEN, COUNT, and EXP are ELisp expressions evaluated
All the above BITLEN, LEN, LE, COUNT, and EXP are ELisp expressions evaluated
in the current lexical context extended with the previous fields.
TYPE can additionally be one of the Bindat type macros defined with
@ -891,7 +886,7 @@ a bindat type expression."
:pe ,(bindat--toplevel 'pack type))))
(eval-and-compile
(defconst bindat--primitives '(byte uint uintr str strz bits fill align
(defconst bindat--primitives '(byte uint str strz bits fill align
struct type vec unit)))
(eval-and-compile
@ -935,9 +930,9 @@ a bindat type expression."
(if ud (help-add-fundoc-usage combined-doc (car ud)) combined-doc)))))
(bindat-defmacro u8 () "Unsigned 8bit integer." '(byte))
(bindat-defmacro sint (bitlen r)
(bindat-defmacro sint (bitlen le)
"Signed integer of size BITLEN.
Bigendian if R is nil and little endian if not."
Big-endian if LE is nil and little-endian if not."
(let ((bl (make-symbol "bitlen"))
(max (make-symbol "max"))
(wrap (make-symbol "wrap")))
@ -945,10 +940,14 @@ Bigendian if R is nil and little endian if not."
(,max (ash 1 (1- ,bl)))
(,wrap (+ ,max ,max)))
(struct :pack-var v
(n if ,r (uintr ,bl) (uint ,bl)
(n uint ,bl ,le
:pack-val (if (< v 0) (+ v ,wrap) v))
:unpack-val (if (>= n ,max) (- n ,wrap) n)))))
(bindat-defmacro uintr (bitlen)
"(deprecated since Emacs-29) Little-endian unsigned integer."
`(uint ,bitlen t))
(bindat-defmacro repeat (count &rest type)
"Like `vec', but unpacks to a list rather than a vector."
`(:pack-var v

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@ -36,7 +36,7 @@
(bindat-type
(type u8)
(opcode u8)
(length uintr 16) ;; little endian order
(length uint 16 'le) ;; little endian order
(id strz 8)
(data vec length)
(_ align 4)))
@ -128,18 +128,17 @@
(r (zerop (% kind 2))))
(dotimes (_ 100)
(let* ((n (random (ash 1 bitlen)))
(i (- n (ash 1 (1- bitlen)))))
(i (- n (ash 1 (1- bitlen))))
(stype (bindat-type sint bitlen r))
(utype (bindat-type if r (uintr bitlen) (uint bitlen))))
(should (equal (bindat-unpack
(bindat-type sint bitlen r)
(bindat-pack (bindat-type sint bitlen r) i))
stype
(bindat-pack stype i))
i))
(when (>= i 0)
(should (equal (bindat-pack
(bindat-type if r (uintr bitlen) (uint bitlen)) i)
(bindat-pack (bindat-type sint bitlen r) i)))
(should (equal (bindat-unpack
(bindat-type if r (uintr bitlen) (uint bitlen))
(bindat-pack (bindat-type sint bitlen r) i))
(should (equal (bindat-pack utype i)
(bindat-pack stype i)))
(should (equal (bindat-unpack utype (bindat-pack stype i))
i))))))))
(defconst bindat-test--LEB128