Stop using allocation trick in fastpath functions (OCaml 4.02).

[ocaml-bitstring.git] / TODO

diff --git a/TODO b/TODO
index ecb0620..ff2a556 100644 (file)
--- a/TODO
+++ b/TODO
@@ -1,4 +1,4 @@
-$Id: TODO,v 1.5 2008-05-07 14:37:00 rjones Exp $
+$Id$

 Major to-do items.
 
 (1) DONE - In bitmatch operator, use patterns not expressions.
 Major to-do items.
 
 (1) DONE - In bitmatch operator, use patterns not expressions.


@@ -9,7 +9,7 @@ Major to-do items.
 
 (4) Provide UInt32 and UInt64 types.
 
 
 (4) Provide UInt32 and UInt64 types.
 

-(5) Allow for specific offsets and alignment.  Something like this:
+(5) DONE - Allow for specific offsets and alignment.  Something like this:

 
     { start : 16;
       another : 16 : offset(256);   (* location would be 256 bits from start *)
 
     { start : 16;
       another : 16 : offset(256);   (* location would be 256 bits from start *)


@@ -33,26 +33,104 @@ Major to-do items.
     Make the error locations fine-grained, particularly so they point to
     individual fields, not the whole match.
 
     Make the error locations fine-grained, particularly so they point to
     individual fields, not the whole match.
 

-(10) Cross-module, persistent, named patterns, see:
+(10) DONE - Cross-module, persistent, named patterns, see:

   http://caml.inria.fr/pub/ml-archives/caml-list/2008/04/25992c9c9fa999fe1d35d961dd9917a2.en.html
 
   http://caml.inria.fr/pub/ml-archives/caml-list/2008/04/25992c9c9fa999fe1d35d961dd9917a2.en.html
 

-(11) Runtime endiannness expressions.  The suggested syntax is:
+(11) DONE -
+     Runtime endiannness expressions.  The suggested syntax is:

 
 

-    { field : len : endianness(expr) }
+    { field : len : endian (expr) }

 
 

-    where expr would evaluate to something like `BigEndian or
-    `LittleEndian.
+    where expr would evaluate to something like BigEndian or
+    LittleEndian.

 
     There are several protocols around where endianness is only
     determined at runtime, examples are libpcap and TIFF.
 
 
     There are several protocols around where endianness is only
     determined at runtime, examples are libpcap and TIFF.
 

-(12) More constant field lengths.
+(12) DONE - More constant field lengths.

 
 

-(13) Implement native endian functions.
+(13) PARTLY DONE - Implement native endian functions.

 
 

-(14) A proper test suite.
+(14) PARTLY DONE - A proper test suite.

 
 

-(15) More examples:
+(15) DONE - More examples:

 
     ELF binaries
     GIF images
 
     ELF binaries
     GIF images

+
+(16) We now know the offset of the current field relative to the
+     whole match.  This may allow more efficient aligned versions
+     of functions to be called (at compile time).  However do note
+     that the offset in the bitstring is usually not known.
+
+(17) PARTLY DONE - Fix the META file.  Current one is very broken.
+
+(18) DONE - check() qualifier:
+
+     { field : 16 : check (field > 100) }
+
+     The check(expr) qualifier will abort the rest of the match if the
+     expression is false.
+
+(19) DONE - bind() qualifier:
+
+     { field : 16 : bind (field * 3) }
+       ^pattern           ^new value
+
+     The bind(expr) qualifier binds the pattern to a new value,
+     equivalent to doing:
+
+     let field = field * 3 in
+     (* remainder of match *)
+
+     There is a question of whether bind() should run before or
+     after when() [best is probably when() first, then bind()].
+
+(20) DONE - save_offset_to() qualifier:
+
+     { field : 16 : save_offset_to (offset), bind (field - offset) }
+
+     or:
+
+     { field : 16 : save_offset_to (field_offset) } ->
+       printf "the offset of field (%d) is %d\n" field field_offset
+
+     save_offset_to(patt) binds the current match offset to
+     the variable, for later use within bind(), when() or
+     any later parts of the match.
+
+(21) derive() so you can add your own variable decls:
+
+     { field : 32 : derive (field_as_int, Int32.to_int field) }
+
+     This would add a let derivation, equivalent to:
+
+     let field_as_int = Int32.to_int field
+
+     allowing you to use both the original field and field_as_int
+     as variables.
+
+     Note you can do this clumsily using bind():
+
+     { field : 32 : bind (field, Int32.to_int field) }
+
+     which redefines 'field' as a pair of (old value, derived value).
+
+(22) Allow constant 0 to be used in constructors to mean a zero-length
+     bitstring of the right length, eg:
+
+     BITSTRING { 0 : 32*8 : bitstring }
+
+     which would be equivalent to:
+
+     BITSTRING { zeroes_bitstring (32*8) : 32*8 : bitstring }
+
+(23) Add predicate Bitstring.is_zero_bitstring : bitstring -> bool
+
+(24) Add a function to turn bitstrings into printable strings.
+
+(25) Folding over bitstrings.  A narrow usage for this is to generate
+     checksums and hashes, where usually you want to fold over every
+     8/16/32-bit word.  So a set of functions which just enabled this
+     would be useful.  (However you still need le/be/ne variations so
+     it involves at least 7 functions).