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

[ocaml-bitstring.git] / TODO

diff --git a/TODO b/TODO
index a3c5981..ff2a556 100644 (file)
--- a/TODO
+++ b/TODO
@@ -63,4 +63,74 @@ Major to-do items.
      of functions to be called (at compile time).  However do note
      that the offset in the bitstring is usually not known.
 
      of functions to be called (at compile time).  However do note
      that the offset in the bitstring is usually not known.
 

-(17) Fix the META file.  Current one is very broken.
+(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).