polymorphic operators.

For instance, when LicDumping expression such as

    map<<map<<+,4>>,5>>

an  alias  node was  created  for  "map<<+,4>>"  (to unnest  iterator
calls). Fut this node is intrically overloaded (polymorphic). In this
change, we  look at  the type this  innr call  is used to  generate a
specialised (mono-morphic) version of the node alias.

Note that we currently still generate type variable when users write

     node mymap = map<<+,4>>;

enum nor a bool.

as many  new local  variables as necessary  so that an  expression is
made at most of one operator.

The rational  for that  is to obtain  a lic  code that is  trivial to
clock check (nested node calls, for example, make it less simple).

The old behavior can still be obtained using --keep-nested-calls.

During  that  change,   I  realised  that  I  did   not  clock  check
asserts. Hence, I have also added this check.

to avoid name clashes in the lic.

Add some tests with various kinds of expr that we can have after a when.

Not yet implemented (assert false): iterators, struct

Add a UnifyClock module, and rename Unify into UnifyType.

nb : a lot of test are now broken, because
   - the clock checking is now plugged ;-)
   - iterators, struct are not yet implemented

It  does not  work, I  have changed  my mind  to use  a  more general
clocking algorithm based on  unification. I commit that current state
just in case I change my mind again...

the parameters  input types are  compatible with Unify.f.   Apply (if
necessary) the resulting substitution to the output parameters.

Also,  when checking array  concat, try  to unify  the types  of both
arrays instead of just checking their equality.

This of course triggers some errors in the non-reg tests.  One of
this error is due to a bug in the parser, where the list of parameter
was inversed twice. I've also fixed that in this change.

type_eff_ext into type_eff btw). The  rationale is to be able to type
alias           on           polymorphic          nodes           (cf
test/should_fail/semantics/bad_call03.lus,  that now  have  a correct
error msg).  It also makes  to code more compact (no more translation
from one  to the  other), and more  general (type_eff_ext  being more
general than type_eff).  User polymorphic nodes should be easy now.

move all the code in parsey.mly into parserUtil.ml (ease the debug).

equations is not done at all yet). Also, print the clock decorations
(when clk) in the generated file.

and PredefEvalClock.

represented. Indeed, it was represented by "HAT_eff of int *
type_eff" instead of "HAT_eff of int * val_exp_eff"

before '..'.

when trying to  unify, e.g., "a^3" and "int^3".   Such kind of things
occured when one imbricates iterators.   In fact, it was not possible
to get it rigth with  the data representation used for node profiles,
which was not sufficiently general.

overloaded operator.

Moreover, do not try to check that int or real constant are ok. It is
the role of the host language.

performed. The resulting code is both more compact, and more general.

It is more  general, since that predef operators  are now represented
by  node_exp_eff, exactly as  user nodes.   Hence, all  the functions
that were  operating on  user nodes via  node_exp_eff (such  as, node
aliasing) works for free on predef op!

In order to be able  to perform that generalisation, it was necessary
to  extend sligthly  the data  structure used  to represent  the node
profile in CompiledData.node_exp_eff with information indicating if a
variable is polymorphic or overloaded.

Not that, currently, polymorphic  or overloaded variables can only be
introduced by predef  operators. But I think it would  be easy to add
those notions for normal user nodes after this change.

New non-reg files boolred now compiles. Those involving
- boolred
- alias on predef.op

(support for fill, red, etc. is coming soon).

In order to add support  for iterators, I have extended the by_pos_op
(and the by_pos_op_eff) data type with a list of static arguments. In
other words, iterators are handled as a particular case of predefined
operators.

not compile them is (well, was) the default...).

also, during pretty-printing, remove the type in the constant definition
(e.g., "const x = 42;" instead of "const x = 42:int;"), except if it is an abstract
constant of course

For non-regression tests, do not use Lazycompiler.test function
anymore and just use  LazyCompiler.node_check instead.

put in the new file compiledDataDump.ml all the stuff
related to string convertions of CompiledData items.

and anonymous structures. I've even found some type errors in the non-reg files!

EvalNode.f -> GetEff.node,
EvalType.f -> GetEff.typ,
EvalEq.f -> GetEff.eq

EvalConst.f (val_exp -> const_eff list) should have been put there too,
but in fact EvalConst.f ougth to be splitted in two parts:
  - val_exp -> val_exp_eff (but this function already exist)
  - val_exp_eff -> const_eff list

Therefore, the signature of EvalConst.f will be changed to:
val_exp_eff -> const_eff list (and will use GetEff.val_exp)

Ditto for eval_array_index.

 eval_array_index : CompiledData.id_solver -> SyntaxTreeCore.val_exp -> int -> int

ougth to be splitted into two functions:
   - CompiledData.id_solver -> SyntaxTreeCore.val_exp_eff
   - SyntaxTreeCore.val_exp_eff -> int -> int

Ditto for eval_array_size

 eval_array_size : CompiledData.id_solver -> SyntaxTreeCore.val_exp -> int

ougth to be splitted into two functions:
   - CompiledData.id_solver -> SyntaxTreeCore.val_exp_eff
   - SyntaxTreeCore.val_exp_eff -> int

arg... evalConst.f est utilis par GettEff.typ !!!

src/syntaxTreeCore.ml (new file)
	Split      syntaxTree.ml      into     syntaxTree.ml      and
	syntaxTreeCore.ml. The idea is that lic2loc should be able to
	use syntaxTreeCore.ml verbatim.

src/lxm.ml
src/lxm.mli
	remove pack_name from  this module, so that it  can be shared
	with  lic2loc too  (this is  mandatory  since it  is used  by
	SyntaxTreeCore)

src/compile.ml
src/compiledData.ml
src/evalConst.ml
src/evalConst.mli
src/evalType.ml
src/evalType.mli
src/expandPack.ml
src/lazyCompiler.ml
src/main.ml
src/parser.mly
src/symbolTab.ml
src/symbolTab.mli
src/syntaxTab.ml
src/syntaxTreeDump.ml
src/syntaxTreeDump.mli
src/test/Makefile
src/test/packs.lus
src/test/test.res.exp
	opening SyntaxTreeCore  module, and inline  the definition of
	Lxm.pack_name.

	Also,  begin  to  replace  oper  by node  or  predef_node  in
	identifiers, in order to get a more consistant naming scheme.

Ident.t is now an abstract data type (instead of a string).
fullid is turned into an Ident.long, and is also made abstract.

Add basic regression tests.

Add "assert false" statements everywhere it was necessary.

Add the fby operator in the syntax.