diogo/yap-6.3
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optimise sub_atom when sub_atom is known.

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This commit is contained in:
Costa Vitor 2009-06-22 15:35:40 -05:00
parent d47560342c
commit d8595221d0
2 changed files with 80 additions and 0 deletions
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65
C/stdpreds.c
View File

@ -2503,6 +2503,70 @@ p_sub_atom_extract(void)
goto start;
}
/* $sub_atom_extract(A,Bef,Size,After,SubAt).*/
static Int
p_sub_atom_fetch(void)
{
Atom at = AtomOfTerm(Deref(ARG1));
Atom subatom = AtomOfTerm(Deref(ARG5));
Int offset = IntegerOfTerm(Deref(ARG6));
if (IsWideAtom(at)) {
wchar_t *s = RepAtom(at)->WStrOfAE;
wchar_t *ins, *where;
Int start, sz, after;
if (!IsWideAtom(subatom)) {
/* first convert to wchar_t */
char *inschars = RepAtom(subatom)->StrOfAE;
Int i;
sz = strlen(inschars);
ins = (wchar_t *)Yap_PreAllocCodeSpace();
while ((ins = (wchar_t *)Yap_PreAllocCodeSpace()) + (sz+1) > (wchar_t *)AuxSp) {
if (!Yap_ExpandPreAllocCodeSpace(sizeof(wchar_t)*(sz+1), NULL, TRUE)) {
Yap_Error(OUT_OF_AUXSPACE_ERROR, ARG5, "allocating temp space in sub_atom/2");
return FALSE;
}
}
for (i=0;i<=sz;i++)
ins[i] = inschars[i];
} else {
ins = RepAtom(subatom)->WStrOfAE;
sz = wcslen(ins);
}
if (!Yap_unify(MkIntegerTerm(sz), ARG3))
return FALSE;
if (!(where = wcsstr(s+offset, ins))) {
return FALSE;
}
if (!Yap_unify(MkIntegerTerm((start = (where-s))), ARG2))
return FALSE;
after = wcslen(s)-(start+sz);
return Yap_unify(MkIntegerTerm(after), ARG4);
} else {
char *s = RepAtom(at)->StrOfAE;
char *ins, *where;
Int start, sz, after;
if (IsWideAtom(subatom)) {
return FALSE;
}
ins = subatom->StrOfAE;
sz = strlen(ins);
if (!Yap_unify(MkIntegerTerm(sz), ARG3))
return FALSE;
if (!(where = strstr(s+offset, ins))) {
return FALSE;
}
if (!Yap_unify(MkIntegerTerm((start = (where-s))), ARG2))
return FALSE;
after = strlen(s)-(start+sz);
return Yap_unify(MkIntegerTerm(after), ARG4);
}
}
static Int
p_abort(void)
@ -3929,6 +3993,7 @@ Yap_InitCPreds(void)
Yap_InitCPred("atom_length", 2, p_atom_length, SafePredFlag);
Yap_InitCPred("$atom_split", 4, p_atom_split, SafePredFlag|HiddenPredFlag);
Yap_InitCPred("$sub_atom_extract", 5, p_sub_atom_extract, HiddenPredFlag);
Yap_InitCPred("$sub_atom_fetch", 6, p_sub_atom_fetch, HiddenPredFlag);
Yap_InitCPred("number_chars", 2, p_number_chars, 0);
Yap_InitCPred("number_atom", 2, p_number_atom, 0);
Yap_InitCPred("number_codes", 2, p_number_codes, 0);

15
pl/utils.yap
View File

@ -520,6 +520,10 @@ sub_atom(At, Bef, Size, After, SubAt) :-
% extract something from an atom
atom(At), integer(Bef), integer(Size), !,
'$sub_atom_extract'(At, Bef, Size, After, SubAt).
sub_atom(At, Bef, Size, After, SubAt) :-
% extract subatom from an atom
atom(At), atom(SubAt), !,
'$do_sub_atom_fetch'(At, Bef, Size, After, SubAt, 0).
sub_atom(At, Bef, Size, After, SubAt) :-
atom(At), !,
atom_codes(At, Atl),
@ -532,6 +536,17 @@ sub_atom(At, Bef, Size, After, SubAt) :-
'$do_error'(type_error(atom,At),sub_atom(At, Bef, Size,After, SubAt)).
'$do_sub_atom_fetch'(At, Bef, Size, After, SubAt, I0) :-
'$sub_atom_fetch'(At, Bef1, Size, After1, SubAt, I0),
(
Bef = Bef1, After = After1
;
Next is Bef1+1,
'$do_sub_atom_fetch'(At, Bef, Size, After, SubAt, Next)
).
'$sub_atom2'(Bef, Atl, Size, After, SubAt, ErrorTerm) :-
var(Bef), !,
'$sub_atombv'(Bef, Size, After, SubAt, Atl, ErrorTerm).