Create and return a new interpreter by cloning the current one.
+perl_clone takes these flags as paramters:
+
+CLONEf_COPY_STACKS - is used to, well, copy the stacks also,
+without it we only clone the data and zero the stacks,
+with it we copy the stacks and the new perl interpreter is
+ready to run at the exact same point as the previous one.
+The pseudo-fork code uses COPY_STACKS while the
+threads->new doesn't.
+
+CLONEf_KEEP_PTR_TABLE
+perl_clone keeps a ptr_table with the pointer of the old
+variable as a key and the new variable as a value,
+this allows it to check if something has been cloned and not
+clone it again but rather just use the value and increase the
+refcount. If KEEP_PTR_TABLE is not set then perl_clone will kill
+the ptr_table using the function
+C<ptr_table_free(PL_ptr_table); PL_ptr_table = NULL;>,
+reason to keep it around is if you want to dup some of your own
+variable who are outside the graph perl scans, example of this
+code is in threads.xs create
+
+CLONEf_CLONE_HOST
+This is a win32 thing, it is ignored on unix, it tells perls
+win32host code (which is c++) to clone itself, this is needed on
+win32 if you want to run two threads at the same time,
+if you just want to do some stuff in a separate perl interpreter
+and then throw it away and return to the original one,
+you don't need to do anything.
+
PerlInterpreter* perl_clone(PerlInterpreter* interp, UV flags)
=for hackers
stored within the hash (as in the case of tied hashes). Otherwise it can
be dereferenced to get the original C<SV*>. Note that the caller is
responsible for suitably incrementing the reference count of C<val> before
-the call, and decrementing it if the function returned NULL.
+the call, and decrementing it if the function returned NULL. Effectively
+a successful hv_store takes ownership of one reference to C<val>. This is
+usually what you want; a newly created SV has a reference count of one, so
+if all your code does is create SVs then store them in a hash, hv_store
+will own the only reference to the new SV, and your code doesn't need to do
+anything further to tidy up. hv_store is not implemented as a call to
+hv_store_ent, and does not create a temporary SV for the key, so if your
+key data is not already in SV form then use hv_store in preference to
+hv_store_ent.
See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
information on how to use this function on tied hashes.
contents of the return value can be accessed using the C<He?> macros
described here. Note that the caller is responsible for suitably
incrementing the reference count of C<val> before the call, and
-decrementing it if the function returned NULL.
+decrementing it if the function returned NULL. Effectively a successful
+hv_store_ent takes ownership of one reference to C<val>. This is
+usually what you want; a newly created SV has a reference count of one, so
+if all your code does is create SVs then store them in a hash, hv_store
+will own the only reference to the new SV, and your code doesn't need to do
+anything further to tidy up. Note that hv_store_ent only reads the C<key>;
+unlike C<val> it does not take ownership of it, so maintaining the correct
+reference count on C<key> is entirely the caller's responsibility. hv_store
+is not implemented as a call to hv_store_ent, and does not create a temporary
+SV for the key, so if your key data is not already in SV form then use
+hv_store in preference to hv_store_ent.
See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
information on how to use this function on tied hashes.
we do the copy, and is also used locally. If C<SV_COW_DROP_PV> is set
then a copy-on-write scalar drops its PV buffer (if any) and becomes
SvPOK_off rather than making a copy. (Used where this scalar is about to be
-set to some other value. In addtion, the C<flags> parameter gets passed to
+set to some other value.) In addition, the C<flags> parameter gets passed to
C<sv_unref_flags()> when unrefing. C<sv_force_normal> calls this function
with flags set to 0.
Returns a pointer to the newly-created string, and sets C<len> to
reflect the new length.
+If you want to convert to UTF8 from other encodings than ASCII,
+see sv_recode_to_utf8().
+
NOTE: this function is experimental and may change or be
removed without notice.
=item is_utf8_string
-Returns true if first C<len> bytes of the given string form a valid UTF8
-string, false otherwise. Note that 'a valid UTF8 string' does not mean
-'a string that contains UTF8' because a valid ASCII string is a valid
-UTF8 string.
+Returns true if first C<len> bytes of the given string form a valid
+UTF8 string, false otherwise. Note that 'a valid UTF8 string' does
+not mean 'a string that contains code points above 0x7F encoded in
+UTF8' because a valid ASCII string is a valid UTF8 string.
bool is_utf8_string(U8 *s, STRLEN len)
=for hackers
Found in file utf8.c
+=item sv_cat_decode
+
+The encoding is assumed to be an Encode object, the PV of the ssv is
+assumed to be octets in that encoding and decoding the input starts
+from the position which (PV + *offset) pointed to. The dsv will be
+concatenated the decoded UTF-8 string from ssv. Decoding will terminate
+when the string tstr appears in decoding output or the input ends on
+the PV of the ssv. The value which the offset points will be modified
+to the last input position on the ssv.
+
+Returns TRUE if the terminator was found, else returns FALSE.
+
+ bool sv_cat_decode(SV* dsv, SV *encoding, SV *ssv, int *offset, char* tstr, int tlen)
+
+=for hackers
+Found in file sv.c
+
=item sv_recode_to_utf8
The encoding is assumed to be an Encode object, on entry the PV