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add rewrites for replace_all

This commit is contained in:
Nikolaj Bjorner 2020-12-07 13:02:20 -08:00
parent 7089610bbd
commit 289cc9de79

View file

@ -673,6 +673,10 @@ br_status seq_rewriter::mk_app_core(func_decl * f, unsigned num_args, expr * con
SASSERT(num_args == 3);
st = mk_seq_replace(args[0], args[1], args[2], result);
break;
case OP_SEQ_REPLACE_ALL:
SASSERT(num_args == 3);
st = mk_seq_replace_all(args[0], args[1], args[2], result);
break;
case OP_SEQ_TO_RE:
SASSERT(num_args == 1);
st = mk_str_to_regexp(args[0], result);
@ -1677,6 +1681,33 @@ br_status seq_rewriter::mk_seq_replace(expr* a, expr* b, expr* c, expr_ref& resu
}
br_status seq_rewriter::mk_seq_replace_all(expr* a, expr* b, expr* c, expr_ref& result) {
if (str().is_empty(b) || b == c) {
result = a;
return BR_DONE;
}
if (a == b) {
result = m().mk_ite(str().mk_is_empty(b), str().mk_empty(m().get_sort(a)), c);
return BR_REWRITE1;
}
zstring s1, s2;
if (str().is_string(a, s1) && str().is_string(b, s2)) {
SASSERT(s2.length() > 0);
if (s1.length() < s2.length()) {
result = a;
return BR_DONE;
}
expr_ref_vector strs(m());
for (unsigned i = 0; i < s1.length() - s2.length(); ++i) {
if (s2 == s1.extract(0, s2.length()-1)) {
strs.push_back(c);
i += s2.length();
}
else
strs.push_back(str().mk_unit(str().mk_char(s1, i)));
}
result = str().mk_concat(strs, m().get_sort(a));
return BR_REWRITE_FULL;
}
return BR_FAILED;
}
@ -1809,7 +1840,6 @@ br_status seq_rewriter::mk_seq_suffix(expr* a, expr* b, expr_ref& result) {
result = m().mk_true();
return BR_DONE;
}
zstring s1, s2;
sort* sort_a = m().get_sort(a);
if (str().is_empty(a)) {
result = m().mk_true();