[PATCH] __SUB__ #10897
Comments
From @cpansproutThis patch adds a __SUB__ keyword that returns the current subroutine, or undef for the main program, a special block, or an eval. If there are no objections, I will add docs and push this shortly before 5.13.8. I first thought of adding this to make recursive lexicals subs easier to write (whenever they are added): my sub foo { __SUB__->() } my sub foo; # the alternative The really neat thing, which I realised only after writing it, is that it allows for recursive closures to be written much more simply: sub make_recursive_function { as opposed to: use Scalar::Util; [Reminder to myself: I need to add it to Opcode.pm as well.] Flags: Site configuration information for perl 5.13.7: Configured by sprout at Thu Dec 9 14:53:58 PST 2010. Summary of my perl5 (revision 5 version 13 subversion 7) configuration: Locally applied patches: @INC for perl 5.13.7: Environment for perl 5.13.7: |
From @cpansproutInline Patchdiff --git a/embed.h b/embed.h
index 5f846f5..f511965 100644
--- a/embed.h
+++ b/embed.h
@@ -1363,6 +1363,7 @@
#define pp_rindex() Perl_pp_rindex(aTHX)
#define pp_rkeys() Perl_pp_rkeys(aTHX)
#define pp_rmdir() Perl_pp_rmdir(aTHX)
+#define pp_runcv() Perl_pp_runcv(aTHX)
#define pp_rv2av() Perl_pp_rv2av(aTHX)
#define pp_rv2cv() Perl_pp_rv2cv(aTHX)
#define pp_rv2gv() Perl_pp_rv2gv(aTHX)
diff --git a/keywords.h b/keywords.h
index 526f3e4..1f63f06 100644
--- a/keywords.h
+++ b/keywords.h
@@ -16,254 +16,255 @@
#define KEY___FILE__ 1
#define KEY___LINE__ 2
#define KEY___PACKAGE__ 3
-#define KEY___DATA__ 4
-#define KEY___END__ 5
-#define KEY_AUTOLOAD 6
-#define KEY_BEGIN 7
-#define KEY_UNITCHECK 8
-#define KEY_CORE 9
-#define KEY_DESTROY 10
-#define KEY_END 11
-#define KEY_INIT 12
-#define KEY_CHECK 13
-#define KEY_abs 14
-#define KEY_accept 15
-#define KEY_alarm 16
-#define KEY_and 17
-#define KEY_atan2 18
-#define KEY_bind 19
-#define KEY_binmode 20
-#define KEY_bless 21
-#define KEY_break 22
-#define KEY_caller 23
-#define KEY_chdir 24
-#define KEY_chmod 25
-#define KEY_chomp 26
-#define KEY_chop 27
-#define KEY_chown 28
-#define KEY_chr 29
-#define KEY_chroot 30
-#define KEY_close 31
-#define KEY_closedir 32
-#define KEY_cmp 33
-#define KEY_connect 34
-#define KEY_continue 35
-#define KEY_cos 36
-#define KEY_crypt 37
-#define KEY_dbmclose 38
-#define KEY_dbmopen 39
-#define KEY_default 40
-#define KEY_defined 41
-#define KEY_delete 42
-#define KEY_die 43
-#define KEY_do 44
-#define KEY_dump 45
-#define KEY_each 46
-#define KEY_else 47
-#define KEY_elsif 48
-#define KEY_endgrent 49
-#define KEY_endhostent 50
-#define KEY_endnetent 51
-#define KEY_endprotoent 52
-#define KEY_endpwent 53
-#define KEY_endservent 54
-#define KEY_eof 55
-#define KEY_eq 56
-#define KEY_eval 57
-#define KEY_exec 58
-#define KEY_exists 59
-#define KEY_exit 60
-#define KEY_exp 61
-#define KEY_fcntl 62
-#define KEY_fileno 63
-#define KEY_flock 64
-#define KEY_for 65
-#define KEY_foreach 66
-#define KEY_fork 67
-#define KEY_format 68
-#define KEY_formline 69
-#define KEY_ge 70
-#define KEY_getc 71
-#define KEY_getgrent 72
-#define KEY_getgrgid 73
-#define KEY_getgrnam 74
-#define KEY_gethostbyaddr 75
-#define KEY_gethostbyname 76
-#define KEY_gethostent 77
-#define KEY_getlogin 78
-#define KEY_getnetbyaddr 79
-#define KEY_getnetbyname 80
-#define KEY_getnetent 81
-#define KEY_getpeername 82
-#define KEY_getpgrp 83
-#define KEY_getppid 84
-#define KEY_getpriority 85
-#define KEY_getprotobyname 86
-#define KEY_getprotobynumber 87
-#define KEY_getprotoent 88
-#define KEY_getpwent 89
-#define KEY_getpwnam 90
-#define KEY_getpwuid 91
-#define KEY_getservbyname 92
-#define KEY_getservbyport 93
-#define KEY_getservent 94
-#define KEY_getsockname 95
-#define KEY_getsockopt 96
-#define KEY_given 97
-#define KEY_glob 98
-#define KEY_gmtime 99
-#define KEY_goto 100
-#define KEY_grep 101
-#define KEY_gt 102
-#define KEY_hex 103
-#define KEY_if 104
-#define KEY_index 105
-#define KEY_int 106
-#define KEY_ioctl 107
-#define KEY_join 108
-#define KEY_keys 109
-#define KEY_kill 110
-#define KEY_last 111
-#define KEY_lc 112
-#define KEY_lcfirst 113
-#define KEY_le 114
-#define KEY_length 115
-#define KEY_link 116
-#define KEY_listen 117
-#define KEY_local 118
-#define KEY_localtime 119
-#define KEY_lock 120
-#define KEY_log 121
-#define KEY_lstat 122
-#define KEY_lt 123
-#define KEY_m 124
-#define KEY_map 125
-#define KEY_mkdir 126
-#define KEY_msgctl 127
-#define KEY_msgget 128
-#define KEY_msgrcv 129
-#define KEY_msgsnd 130
-#define KEY_my 131
-#define KEY_ne 132
-#define KEY_next 133
-#define KEY_no 134
-#define KEY_not 135
-#define KEY_oct 136
-#define KEY_open 137
-#define KEY_opendir 138
-#define KEY_or 139
-#define KEY_ord 140
-#define KEY_our 141
-#define KEY_pack 142
-#define KEY_package 143
-#define KEY_pipe 144
-#define KEY_pop 145
-#define KEY_pos 146
-#define KEY_print 147
-#define KEY_printf 148
-#define KEY_prototype 149
-#define KEY_push 150
-#define KEY_q 151
-#define KEY_qq 152
-#define KEY_qr 153
-#define KEY_quotemeta 154
-#define KEY_qw 155
-#define KEY_qx 156
-#define KEY_rand 157
-#define KEY_read 158
-#define KEY_readdir 159
-#define KEY_readline 160
-#define KEY_readlink 161
-#define KEY_readpipe 162
-#define KEY_recv 163
-#define KEY_redo 164
-#define KEY_ref 165
-#define KEY_rename 166
-#define KEY_require 167
-#define KEY_reset 168
-#define KEY_return 169
-#define KEY_reverse 170
-#define KEY_rewinddir 171
-#define KEY_rindex 172
-#define KEY_rmdir 173
-#define KEY_s 174
-#define KEY_say 175
-#define KEY_scalar 176
-#define KEY_seek 177
-#define KEY_seekdir 178
-#define KEY_select 179
-#define KEY_semctl 180
-#define KEY_semget 181
-#define KEY_semop 182
-#define KEY_send 183
-#define KEY_setgrent 184
-#define KEY_sethostent 185
-#define KEY_setnetent 186
-#define KEY_setpgrp 187
-#define KEY_setpriority 188
-#define KEY_setprotoent 189
-#define KEY_setpwent 190
-#define KEY_setservent 191
-#define KEY_setsockopt 192
-#define KEY_shift 193
-#define KEY_shmctl 194
-#define KEY_shmget 195
-#define KEY_shmread 196
-#define KEY_shmwrite 197
-#define KEY_shutdown 198
-#define KEY_sin 199
-#define KEY_sleep 200
-#define KEY_socket 201
-#define KEY_socketpair 202
-#define KEY_sort 203
-#define KEY_splice 204
-#define KEY_split 205
-#define KEY_sprintf 206
-#define KEY_sqrt 207
-#define KEY_srand 208
-#define KEY_stat 209
-#define KEY_state 210
-#define KEY_study 211
-#define KEY_sub 212
-#define KEY_substr 213
-#define KEY_symlink 214
-#define KEY_syscall 215
-#define KEY_sysopen 216
-#define KEY_sysread 217
-#define KEY_sysseek 218
-#define KEY_system 219
-#define KEY_syswrite 220
-#define KEY_tell 221
-#define KEY_telldir 222
-#define KEY_tie 223
-#define KEY_tied 224
-#define KEY_time 225
-#define KEY_times 226
-#define KEY_tr 227
-#define KEY_truncate 228
-#define KEY_uc 229
-#define KEY_ucfirst 230
-#define KEY_umask 231
-#define KEY_undef 232
-#define KEY_unless 233
-#define KEY_unlink 234
-#define KEY_unpack 235
-#define KEY_unshift 236
-#define KEY_untie 237
-#define KEY_until 238
-#define KEY_use 239
-#define KEY_utime 240
-#define KEY_values 241
-#define KEY_vec 242
-#define KEY_wait 243
-#define KEY_waitpid 244
-#define KEY_wantarray 245
-#define KEY_warn 246
-#define KEY_when 247
-#define KEY_while 248
-#define KEY_write 249
-#define KEY_x 250
-#define KEY_xor 251
-#define KEY_y 252
+#define KEY___SUB__ 4
+#define KEY___DATA__ 5
+#define KEY___END__ 6
+#define KEY_AUTOLOAD 7
+#define KEY_BEGIN 8
+#define KEY_UNITCHECK 9
+#define KEY_CORE 10
+#define KEY_DESTROY 11
+#define KEY_END 12
+#define KEY_INIT 13
+#define KEY_CHECK 14
+#define KEY_abs 15
+#define KEY_accept 16
+#define KEY_alarm 17
+#define KEY_and 18
+#define KEY_atan2 19
+#define KEY_bind 20
+#define KEY_binmode 21
+#define KEY_bless 22
+#define KEY_break 23
+#define KEY_caller 24
+#define KEY_chdir 25
+#define KEY_chmod 26
+#define KEY_chomp 27
+#define KEY_chop 28
+#define KEY_chown 29
+#define KEY_chr 30
+#define KEY_chroot 31
+#define KEY_close 32
+#define KEY_closedir 33
+#define KEY_cmp 34
+#define KEY_connect 35
+#define KEY_continue 36
+#define KEY_cos 37
+#define KEY_crypt 38
+#define KEY_dbmclose 39
+#define KEY_dbmopen 40
+#define KEY_default 41
+#define KEY_defined 42
+#define KEY_delete 43
+#define KEY_die 44
+#define KEY_do 45
+#define KEY_dump 46
+#define KEY_each 47
+#define KEY_else 48
+#define KEY_elsif 49
+#define KEY_endgrent 50
+#define KEY_endhostent 51
+#define KEY_endnetent 52
+#define KEY_endprotoent 53
+#define KEY_endpwent 54
+#define KEY_endservent 55
+#define KEY_eof 56
+#define KEY_eq 57
+#define KEY_eval 58
+#define KEY_exec 59
+#define KEY_exists 60
+#define KEY_exit 61
+#define KEY_exp 62
+#define KEY_fcntl 63
+#define KEY_fileno 64
+#define KEY_flock 65
+#define KEY_for 66
+#define KEY_foreach 67
+#define KEY_fork 68
+#define KEY_format 69
+#define KEY_formline 70
+#define KEY_ge 71
+#define KEY_getc 72
+#define KEY_getgrent 73
+#define KEY_getgrgid 74
+#define KEY_getgrnam 75
+#define KEY_gethostbyaddr 76
+#define KEY_gethostbyname 77
+#define KEY_gethostent 78
+#define KEY_getlogin 79
+#define KEY_getnetbyaddr 80
+#define KEY_getnetbyname 81
+#define KEY_getnetent 82
+#define KEY_getpeername 83
+#define KEY_getpgrp 84
+#define KEY_getppid 85
+#define KEY_getpriority 86
+#define KEY_getprotobyname 87
+#define KEY_getprotobynumber 88
+#define KEY_getprotoent 89
+#define KEY_getpwent 90
+#define KEY_getpwnam 91
+#define KEY_getpwuid 92
+#define KEY_getservbyname 93
+#define KEY_getservbyport 94
+#define KEY_getservent 95
+#define KEY_getsockname 96
+#define KEY_getsockopt 97
+#define KEY_given 98
+#define KEY_glob 99
+#define KEY_gmtime 100
+#define KEY_goto 101
+#define KEY_grep 102
+#define KEY_gt 103
+#define KEY_hex 104
+#define KEY_if 105
+#define KEY_index 106
+#define KEY_int 107
+#define KEY_ioctl 108
+#define KEY_join 109
+#define KEY_keys 110
+#define KEY_kill 111
+#define KEY_last 112
+#define KEY_lc 113
+#define KEY_lcfirst 114
+#define KEY_le 115
+#define KEY_length 116
+#define KEY_link 117
+#define KEY_listen 118
+#define KEY_local 119
+#define KEY_localtime 120
+#define KEY_lock 121
+#define KEY_log 122
+#define KEY_lstat 123
+#define KEY_lt 124
+#define KEY_m 125
+#define KEY_map 126
+#define KEY_mkdir 127
+#define KEY_msgctl 128
+#define KEY_msgget 129
+#define KEY_msgrcv 130
+#define KEY_msgsnd 131
+#define KEY_my 132
+#define KEY_ne 133
+#define KEY_next 134
+#define KEY_no 135
+#define KEY_not 136
+#define KEY_oct 137
+#define KEY_open 138
+#define KEY_opendir 139
+#define KEY_or 140
+#define KEY_ord 141
+#define KEY_our 142
+#define KEY_pack 143
+#define KEY_package 144
+#define KEY_pipe 145
+#define KEY_pop 146
+#define KEY_pos 147
+#define KEY_print 148
+#define KEY_printf 149
+#define KEY_prototype 150
+#define KEY_push 151
+#define KEY_q 152
+#define KEY_qq 153
+#define KEY_qr 154
+#define KEY_quotemeta 155
+#define KEY_qw 156
+#define KEY_qx 157
+#define KEY_rand 158
+#define KEY_read 159
+#define KEY_readdir 160
+#define KEY_readline 161
+#define KEY_readlink 162
+#define KEY_readpipe 163
+#define KEY_recv 164
+#define KEY_redo 165
+#define KEY_ref 166
+#define KEY_rename 167
+#define KEY_require 168
+#define KEY_reset 169
+#define KEY_return 170
+#define KEY_reverse 171
+#define KEY_rewinddir 172
+#define KEY_rindex 173
+#define KEY_rmdir 174
+#define KEY_s 175
+#define KEY_say 176
+#define KEY_scalar 177
+#define KEY_seek 178
+#define KEY_seekdir 179
+#define KEY_select 180
+#define KEY_semctl 181
+#define KEY_semget 182
+#define KEY_semop 183
+#define KEY_send 184
+#define KEY_setgrent 185
+#define KEY_sethostent 186
+#define KEY_setnetent 187
+#define KEY_setpgrp 188
+#define KEY_setpriority 189
+#define KEY_setprotoent 190
+#define KEY_setpwent 191
+#define KEY_setservent 192
+#define KEY_setsockopt 193
+#define KEY_shift 194
+#define KEY_shmctl 195
+#define KEY_shmget 196
+#define KEY_shmread 197
+#define KEY_shmwrite 198
+#define KEY_shutdown 199
+#define KEY_sin 200
+#define KEY_sleep 201
+#define KEY_socket 202
+#define KEY_socketpair 203
+#define KEY_sort 204
+#define KEY_splice 205
+#define KEY_split 206
+#define KEY_sprintf 207
+#define KEY_sqrt 208
+#define KEY_srand 209
+#define KEY_stat 210
+#define KEY_state 211
+#define KEY_study 212
+#define KEY_sub 213
+#define KEY_substr 214
+#define KEY_symlink 215
+#define KEY_syscall 216
+#define KEY_sysopen 217
+#define KEY_sysread 218
+#define KEY_sysseek 219
+#define KEY_system 220
+#define KEY_syswrite 221
+#define KEY_tell 222
+#define KEY_telldir 223
+#define KEY_tie 224
+#define KEY_tied 225
+#define KEY_time 226
+#define KEY_times 227
+#define KEY_tr 228
+#define KEY_truncate 229
+#define KEY_uc 230
+#define KEY_ucfirst 231
+#define KEY_umask 232
+#define KEY_undef 233
+#define KEY_unless 234
+#define KEY_unlink 235
+#define KEY_unpack 236
+#define KEY_unshift 237
+#define KEY_untie 238
+#define KEY_until 239
+#define KEY_use 240
+#define KEY_utime 241
+#define KEY_values 242
+#define KEY_vec 243
+#define KEY_wait 244
+#define KEY_waitpid 245
+#define KEY_wantarray 246
+#define KEY_warn 247
+#define KEY_when 248
+#define KEY_while 249
+#define KEY_write 250
+#define KEY_x 251
+#define KEY_xor 252
+#define KEY_y 253
/* ex: set ro: */
diff --git a/opcode.h b/opcode.h
index 122c67f..0a9f94d 100644
--- a/opcode.h
+++ b/opcode.h
@@ -398,6 +398,7 @@ EXTCONST char* const PL_op_name[] = {
"rkeys",
"rvalues",
"transr",
+ "runcv",
};
#endif
@@ -775,6 +776,7 @@ EXTCONST char* const PL_op_desc[] = {
"keys on reference",
"values on reference",
"transliteration (tr///)",
+ "__SUB__",
};
#endif
@@ -1166,6 +1168,7 @@ EXT Perl_ppaddr_t PL_ppaddr[] /* or perlvars.h */
Perl_pp_rkeys,
Perl_pp_rkeys, /* Perl_pp_rvalues */
Perl_pp_trans, /* Perl_pp_transr */
+ Perl_pp_runcv,
}
#endif
#ifdef PERL_PPADDR_INITED
@@ -1554,6 +1557,7 @@ EXT Perl_check_t PL_check[] /* or perlvars.h */
Perl_ck_each, /* rkeys */
Perl_ck_each, /* rvalues */
Perl_ck_match, /* transr */
+ Perl_ck_null, /* runcv */
}
#endif
#ifdef PERL_CHECK_INITED
@@ -1936,6 +1940,7 @@ EXTCONST U32 PL_opargs[] = {
0x00001b08, /* rkeys */
0x00001b08, /* rvalues */
0x00001804, /* transr */
+ 0x00000004, /* runcv */
};
#endif
diff --git a/opnames.h b/opnames.h
index 609c6e2..3e14f30 100644
--- a/opnames.h
+++ b/opnames.h
@@ -385,10 +385,11 @@ typedef enum opcode {
OP_RKEYS = 367,
OP_RVALUES = 368,
OP_TRANSR = 369,
+ OP_RUNCV = 370,
OP_max
} opcode;
-#define MAXO 370
+#define MAXO 371
#define OP_phoney_INPUT_ONLY -1
#define OP_phoney_OUTPUT_ONLY -2
diff --git a/perl_keyword.pl b/perl_keyword.pl
index 73128c3..9bea3e8 100644
--- a/perl_keyword.pl
+++ b/perl_keyword.pl
@@ -12,7 +12,8 @@ my @pos = qw(__DATA__ __END__ AUTOLOAD BEGIN CHECK DESTROY default defined
split state study sub tr use undef UNITCHECK until
unless when while y);
-my @neg = qw(__FILE__ __LINE__ __PACKAGE__ and abs alarm atan2 accept bless
+my @neg = qw(__FILE__ __LINE__ __PACKAGE__ __SUB__
+ and abs alarm atan2 accept bless
break bind binmode CORE cmp chr cos chop close chdir chomp chmod
chown crypt chroot caller connect closedir continue die dump
dbmopen dbmclose eq eof exp exit exec each endgrent endpwent
diff --git a/pp.c b/pp.c
index 47cf756..0126061 100644
--- a/pp.c
+++ b/pp.c
@@ -6162,6 +6162,14 @@ PP(pp_boolkeys)
RETURN;
}
+PP(pp_runcv)
+{
+ dSP;
+ CV * const cv = find_runcv(NULL);
+ XPUSHs(CvUNIQUE(cv) ? &PL_sv_undef : sv_2mortal(newRV((SV *)cv)));
+ RETURN;
+}
+
/*
* Local variables:
* c-indentation-style: bsd
diff --git a/pp.sym b/pp.sym
index 11e8f78..bdafb6e 100644
--- a/pp.sym
+++ b/pp.sym
@@ -414,5 +414,6 @@ Perl_pp_reach
Perl_pp_rkeys
Perl_pp_rvalues
Perl_pp_transr
+Perl_pp_runcv
# ex: set ro:
diff --git a/proto.h b/proto.h
index c4df3e2..b621af6 100644
--- a/proto.h
+++ b/proto.h
@@ -3147,6 +3147,7 @@ PERL_CALLCONV OP * Perl_pp_right_shift(pTHX);
PERL_CALLCONV OP * Perl_pp_rindex(pTHX);
PERL_CALLCONV OP * Perl_pp_rkeys(pTHX);
PERL_CALLCONV OP * Perl_pp_rmdir(pTHX);
+PERL_CALLCONV OP * Perl_pp_runcv(pTHX);
PERL_CALLCONV OP * Perl_pp_rv2av(pTHX);
PERL_CALLCONV OP * Perl_pp_rv2cv(pTHX);
PERL_CALLCONV OP * Perl_pp_rv2gv(pTHX);
diff --git a/regen/keywords.pl b/regen/keywords.pl
index 381e098..b19f2b1 100755
--- a/regen/keywords.pl
+++ b/regen/keywords.pl
@@ -64,6 +64,7 @@ NULL
__FILE__
__LINE__
__PACKAGE__
+__SUB__
__DATA__
__END__
AUTOLOAD
diff --git a/regen/opcode.pl b/regen/opcode.pl
index bd3d55a..84d8b69 100755
--- a/regen/opcode.pl
+++ b/regen/opcode.pl
@@ -1106,3 +1106,5 @@ rvalues values on reference ck_each t% S
# y///r
transr transliteration (tr///) ck_match is" S
+
+runcv __SUB__ ck_null s0
diff --git a/toke.c b/toke.c
index ef14c18..e750ee0 100644
--- a/toke.c
+++ b/toke.c
@@ -6898,6 +6898,10 @@ Perl_yylex(pTHX)
: &PL_sv_undef));
TERM(THING);
+ case KEY___SUB__:
+ pl_yylval.opval = (OP*)newOP(OP_RUNCV, 0);
+ TERM(THING);
+
case KEY___DATA__:
case KEY___END__: {
GV *gv;
@@ -10289,7 +10293,7 @@ Perl_keyword (pTHX_ const char *name, I32 len, bool all_keywords)
goto unknown;
}
- case 7: /* 29 tokens of length 7 */
+ case 7: /* 30 tokens of length 7 */
switch (name[0])
{
case 'D':
@@ -10306,14 +10310,35 @@ Perl_keyword (pTHX_ const char *name, I32 len, bool all_keywords)
goto unknown;
case '_':
- if (name[1] == '_' &&
- name[2] == 'E' &&
- name[3] == 'N' &&
- name[4] == 'D' &&
- name[5] == '_' &&
- name[6] == '_')
- { /* __END__ */
- return KEY___END__;
+ if (name[1] == '_')
+ {
+ switch (name[2])
+ {
+ case 'E':
+ if (name[3] == 'N' &&
+ name[4] == 'D' &&
+ name[5] == '_' &&
+ name[6] == '_')
+ { /* __END__ */
+ return KEY___END__;
+ }
+
+ goto unknown;
+
+ case 'S':
+ if (name[3] == 'U' &&
+ name[4] == 'B' &&
+ name[5] == '_' &&
+ name[6] == '_')
+ { /* __SUB__ */
+ return -KEY___SUB__;
+ }
+
+ goto unknown;
+
+ default:
+ goto unknown;
+ }
}
goto unknown; |
From @AbigailOn Sun, Dec 12, 2010 at 12:26:07PM -0800, Father Chrysostomos wrote:
Technically, it could break programs, as in theory someone could have a sub I think this is going to be very handy. I see opportunity for obfuscation Abigail |
|
The RT System itself - Status changed from 'new' to 'open' |
From @cpansproutOn Dec 12, 2010, at 12:36 PM, Abigail via RT wrote:
I thought such names were reserved.
Twisted, eh? How about this? ()=@==split" ","Just another Perl hacker,\n"; @@=("Perl hacker,\n",'Just another '), use constant{Just=>another=>Perl=>hacker=>};$\=",\n"; perl -e 'print do{{&{sub{"Just another Perl hacker,\n"}},last}}' perl5.12.2 -e '$_{0+\$_}="Just another Perl hacker,\n";@INC=sub{\\$_};print$_{require _};sub SCALAR{$_[0]};' |
From @AbigailOn Sun, Dec 12, 2010 at 12:52:08PM -0800, Father Chrysostomos wrote:
If it is, it's neither enforced, or even protected by a warning: $ perl -wE 'sub __SUB__ {sub {say "Foo"}} __SUB__ -> ()' Abigail |
From @raflFather Chrysostomos (via RT) <perlbug-followup@perl.org> writes:
Using '__SUB__' made me think it was a compile-time constant such as Why not make it look like a regular function or keyword, such as sub { In fact this is already available on CPAN as Devel::Caller. Is this |
From @sciuriusAbigail <abigail@abigail.be> writes:
Neither are subroutines/variable names with all UPPERCASE. More important is whether it is a keyword, or a compile time constant -- Johan |
From @ikegamiOn Mon, Dec 13, 2010 at 2:09 AM, Johan Vromans <jvromans@squirrel.nl> wrote:
As proposed, it's not constant. |
From @sciurius[Quoting Eric Brine, on December 13 2010, 02:51, in "Re: [perl #80628] [P"]
Then please do not call it __SUB__. What would be the difference with (caller(0))[3] ? -- Johan |
From @demerphqOn 12 December 2010 21:26, Father Chrysostomos
I long ago suggested this, but recommended it be associated to a variable: $^SUB And in fact rafael put a nearly complete module on cpan for this. But i would love to see this added to the language. Yves -- |
From @demerphqOn 13 December 2010 10:26, demerphq <demerphq@gmail.com> wrote:
And this was exactly the reason i recommended a $^SUB "tied" variable Perhaps if the back compat police dislike __SUB__ you can make it work cheers, |
From @demerphqOn 13 December 2010 10:29, demerphq <demerphq@gmail.com> wrote:
For the record: I originally proposed it be called ${^THIS_SUB} (which Message-ID: <9b18b3110706261235y5ea26d9w516e8444b293c32d@mail.gmail.com> In that thread Rafael replied with the module Sub::Current on cpan http://search.cpan.org/~rgarcia/Sub-Current-0.02/lib/Sub/Current.pm It was also discussed in a number or other threads. Yves -- |
From @AbigailOn Mon, Dec 13, 2010 at 09:07:00AM +0100, Johan Vromans wrote:
Because the latter doesn't work? $ perl -wE '$f = sub {say "Hello"; (caller (0)) [3] -> () if @_}; $f -> (1)' (caller (0)) [3] requires an entry in the symbol table - which not every Abigail |
From @demerphqOn 13 December 2010 10:42, Abigail <abigail@abigail.be> wrote:
Right. __SUB__ would have to resolve as a coderef, otherwise the point The whole idea is to have a non-refcount incremented identifier that Its principle advantage would be that it would allow us to have Johan: do *you* know how to create a recursive closure that does not cheers, -- |
From @demerphqOn 13 December 2010 09:07, Johan Vromans <jvromans@squirrel.nl> wrote:
This is why i proposed using a $^THIS_SUB "magic tied var" for the purpose. Yves -- |
From @sciurius[Quoting demerphq, on December 13 2010, 10:48, in "Re: [perl #80628] [P"]
Sounds like a very good idea to me. My main objection against __SUB__ is that __XXX__ things are currently -- Johan |
From @AbigailOn Mon, Dec 13, 2010 at 11:32:45AM +0100, Johan Vromans wrote:
I wouldn't say __END__ and __DATA__ (probably the most well-known, and So, I don't really buy the "__SUB__ confuses me, because it isn't a __XXX__ things I know about, in order how often I see it used in code: __END__: Special token <huge gap> __FILE__: Compile-time constant Now, I'd prefer a short token, and I certainly don't mind having a variable, Abigail |
From @demerphqOn 13 December 2010 11:42, Abigail <abigail@abigail.be> wrote:
I think johan meant it in the sense that you dont expect to be able to Yves -- |
From @sciurius[Quoting demerphq, on December 13 2010, 12:33, in "Re: [perl #80628] [P"]
I tend to agree, even with $SUB (cf. -- Johan |
From @AbigailOn Mon, Dec 13, 2010 at 12:33:24PM +0100, demerphq wrote:
Good point. But that, IMO, would favour __SUB__ over $^SUB. The latter may give the Abigail |
From @demerphqOn 13 December 2010 13:04, Abigail <abigail@abigail.be> wrote:
Yes right. I'm happy with FC's patch, and would like to see it go in. The only that might be odd with it is that it would return a ref, and cheers, -- |
From zefram@fysh.orgdemerphq wrote:
A variable is a poor model for this. I think it's best accessed via static OP * static OP * BOOT: void With a little more work, this can be backported to older Perl versions -zefram |
From zefram@fysh.orgI wrote:
Trying again: XPUSHs(sv_2mortal(newRV_noinc((SV*)cxstack[cxstack_ix].blk_sub.cv))); -zefram |
From @AbigailOn Mon, Dec 13, 2010 at 01:38:02PM +0100, demerphq wrote:
I forgot one here: __PACKAGE__: Compile-time constant
Yes, but people do write "__PACKAGE__ -> ... ()" without being freaked Abigail |
From @demerphqOn 13 December 2010 13:59, Zefram <zefram@fysh.org> wrote:
Yes. But I think people can deal with that, it isnt much different
That is done by Rafael in Sub::Current. He uses ROUTINE() for this purpose. Yves. -- |
From @lizmatOn Dec 13, 2010, at 5:05 PM, demerphq wrote:
Please note that __PACKAGE__ and __LINE__ are settable nonetheless, using #line and -package- .
FWIW, $^SUB feels more natural to me. Liz |
From @ikegamiOn Mon, Dec 13, 2010 at 3:07 AM, Johan Vromans <jvromans@squirrel.nl> wrote:
caller[3] doesn't work for anon subs.
It was specifically proposed that __SUB__ would return a reference in at It's more like SUPER than __FILE__ in a sense. Maybe something without - Eric |
From @demerphqOn 13 December 2010 17:09, Eric Brine <ikegami@adaelis.com> wrote:
It seen's to me that it MUST return a reference in ALL situations. cheers, -- |
From @demerphqOn 12 December 2010 21:26, Father Chrysostomos
And this demonstrates why the patch would be useful. Even FC got the recipe wrong. :-) It should return $life_raft, not $sub, otherwise $sub will be a "dead cheers, -- |
From @demerphqOn 13 December 2010 17:33, Zefram <zefram@fysh.org> wrote:
Personally I think that Scalar::Util, Data::Alias and friends taught The reasons I see for putting it in core are: a) it needs XS to be With a CPAN module there is no contract between Perl and the community A CPAN module on the other may fall out of sync with perl and be We have also seen that in many environments it is anywhere from nearly This is a language feature that allows us to do something that is cheers, -- |
From @demerphqOn 13 December 2010 17:47, Abigail <abigail@abigail.be> wrote:
And the fact that it not returning a reference would almost certainly For instance the same kind of problem we see here: $ perl -MCarp -le'sub foo { confess "foo" } sub baz { confess "baz" } If we returned anything but a code reference I reckon one could cook cheers, -- |
From @obraI'd rather this functionality live on CPAN until there's a clear consensus that it On Mon, Dec 13, 2010 at 05:35:45PM +0100, Florian Ragwitz wrote:
-- |
From @demerphqOn 13 December 2010 21:17, Jesse Vincent <jesse@fsck.com> wrote:
Jesse noted to me in IRC that this is due to the upcoming code freeze, cheers, -- |
From @obraOn Mon, Dec 13, 2010 at 03:17:11PM -0500, Jesse Vincent wrote:
I somewhat misphrased this - We're very close to the |
From @nwc10On Mon, Dec 13, 2010 at 07:03:32PM +0100, demerphq wrote:
You're proposing a technical fix to a political problem. We can't include all of CPAN in the core just because other people wish This is one of my hot buttons and I will argue against it until I am driven Nicholas Clark |
From @demerphqOn 14 December 2010 18:10, Nicholas Clark <nick@ccl4.org> wrote:
On one level yes, on another level no. Its a technical problem that it On the other hand yes, we have devs in our community who work in
This is a straw man argument. Nobody is arguing about including all of CPAN. We are arguing about including critical XS code that cannot reasonably This doesn't apply to pure perl as there is always a workaround in This DOES NOT apply to XS code. And even with XS code its not like
I don't really like the threat here Nicholas, especially given it is If you really have a good argument for why this idea shouldn't move cheers, -- |
From @leonerdOn Mon, Dec 13, 2010 at 10:47:01AM +0100, demerphq wrote:
use CPS qw( kwhile ); kwhile( $knext->() HTH, -- leonerd@leonerd.org.uk |
From @leonerdOn Mon, Dec 13, 2010 at 04:33:19PM +0000, Zefram wrote:
+1 First off, there's callee http://search.cpan.org/~marcel/callee-1.100820/lib/callee.pm Secondly, if you want it for the purpose of recursive functions, try CPS http://search.cpan.org/~pevans/CPS-0.10/lib/CPS.pm use CPS qw( kwhile ); kwhile( $knext->(); It also includes some added magic to not blow up the stack if you call CPS is pure-perl. -- leonerd@leonerd.org.uk |
From zefram@fysh.orgdemerphq wrote:
This can actually be achieved without either a statically self-referential my $w = sub { my($v, $x) = @_; my $factorial = print $factorial->(5), "\n"; This technique can be extended to arbitrarily many mutually-recursive (Thanks to LeoNerd for inspiring me to go in a theoretical direction.) -zefram |
From @cpansproutOn Mon Dec 13 13:35:19 2010, jesse wrote:
OK, now that we’re past that, let me address some objections that came up: 1) That __SUB__ is not a compile-time constant like its predecessors. That __PACKAGE__ and __LINE__ are compile-time constants is an 2) That this should be a CPAN module, not part of core. One reason I think we should have this in core is that JavaScript And the symmetry with package/__PACKAGE__ is nice: |
From @sciurius"Father Chrysostomos via RT" <perlbug-followup@perl.org> writes:
I revert my former objections. You have my blessing. -- Johan |
From @sciurius"Father Chrysostomos via RT" <perlbug-followup@perl.org> writes:
Some finetuning. 1. CPAN module means: a bunch of Perl and XS (if necessary) that can be Programs need to 'use' Some::Thing to use it. 2. Core means: it's there and works with this and all future Perl 2a. It can still be a module; 'use' Some::Thing is required. 2b. It can be a feature; 'use feature' or equivalent is required. 2c. It can be built-in. It's just there. Technically, anything new can be implemented in any of the above ways. Considering all this, I'd vote for __SUB__ to fall in category 2c. -- Johan |
From @xdgOn Mon, Dec 13, 2010 at 7:04 AM, Abigail <abigail@abigail.be> wrote:
+1 |
From zefram@fysh.orgSince a satisfactorily functional version of __SUB__ already exists The specific name "__SUB__" can easily be added to Sub::Current alongside If this feature is important enough that it ought to be available to I'm happy to help tweak the Sub::Current implementation. I'm neutral -zefram |
From @ap* Zefram <zefram@fysh.org> [2011-06-13 21:25]:
I’d prefer any solution that doesn’t require `use Sub::Current` |
From zefram@fysh.orgAristotle Pagaltzis wrote:
You just need to write this package once to define your preferred package BeLike::Aristotle; Then you can get all the features you like in one declaration: use BeLike::Aristotle; sub factorial { $_[0] == 0 ? 1 : $_[0] * __SUB__->($_[0] - 1) } -zefram |
From @xdgOn Mon, Jun 13, 2011 at 3:24 PM, Zefram <zefram@fysh.org> wrote:
One thing i like about a built-in __SUB__ is that it doesn't pollute
What do you see as the "complications"? -- David |
From zefram@fysh.orgDavid Golden wrote:
I like that too, so much that I modularised it: use Sub::Current (); or, if the name supplied by the module is OK: use Lexical::Import "Sub::Current"; or combining it with Aristotle's issue: sub BeLike::Aristotle::import {
Version portability is a biggie: Sub::Current is available on any Perl -zefram |
From @tseeHi Zefram, hi all, On 06/13/2011 10:54 PM, Zefram wrote:
I strongly disagree. Adding new features to new versions of software is __SUB__ should be part of the core (and NOT require a module load) as By the way: Those loader bundles are a nightmare in practice. Quite Best regards, |
From @TuxOn Tue, 14 Jun 2011 08:15:39 +0200, Steffen Mueller <smueller@cpan.org>
+1 -- |
From @khwilliamsonOn 06/14/2011 01:26 AM, H.Merijn Brand wrote:
+1 |
From @xdgOn Tue, Jun 14, 2011 at 10:57 AM, Karl Williamson
+1 |
From @cpansproutOn Mon Jun 13 13:55:12 2011, zefram@fysh.org wrote:
I’m already working on that. Is that sufficient to address your concern? |
From [Unknown Contact. See original ticket]On Mon Jun 13 13:55:12 2011, zefram@fysh.org wrote:
I’m already working on that. Is that sufficient to address your concern? |
From @cpansproutNow in blead as 84ed010, but the final patch looks quite different. |
|
@cpansprout - Status changed from 'open' to 'resolved' |
Migrated from rt.perl.org#80628 (status was 'resolved')
Searchable as RT80628$
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