Add the `isa` operator

Adds a new infix operator named `isa`, with the semantics that

  $x isa SomeClass

is true if and only if `$x` is a blessed object reference that is either
`SomeClass` directly, or includes the class somewhere in its @ISA
hierarchy. It is false without warning or error for non-references or
non-blessed references.

This operator respects `->isa` method overloading, and is intended to
replace boilerplate code such as

  use Scalar::Util 'blessed';

  blessed($x) and $x->isa("SomeClass")

1 files changed, 147 insertions, 146 deletions

diff --git a/keywords.h b/keywords.h
index 2b1d598a4e..23fa6944d8 100644
--- a/keywords.h
+++ b/keywords.h
@@ -123,152 +123,153 @@
 #define KEY_index		107
 #define KEY_int			108
 #define KEY_ioctl		109
-#define KEY_join		110
-#define KEY_keys		111
-#define KEY_kill		112
-#define KEY_last		113
-#define KEY_lc			114
-#define KEY_lcfirst		115
-#define KEY_le			116
-#define KEY_length		117
-#define KEY_link		118
-#define KEY_listen		119
-#define KEY_local		120
-#define KEY_localtime		121
-#define KEY_lock		122
-#define KEY_log			123
-#define KEY_lstat		124
-#define KEY_lt			125
-#define KEY_m			126
-#define KEY_map			127
-#define KEY_mkdir		128
-#define KEY_msgctl		129
-#define KEY_msgget		130
-#define KEY_msgrcv		131
-#define KEY_msgsnd		132
-#define KEY_my			133
-#define KEY_ne			134
-#define KEY_next		135
-#define KEY_no			136
-#define KEY_not			137
-#define KEY_oct			138
-#define KEY_open		139
-#define KEY_opendir		140
-#define KEY_or			141
-#define KEY_ord			142
-#define KEY_our			143
-#define KEY_pack		144
-#define KEY_package		145
-#define KEY_pipe		146
-#define KEY_pop			147
-#define KEY_pos			148
-#define KEY_print		149
-#define KEY_printf		150
-#define KEY_prototype		151
-#define KEY_push		152
-#define KEY_q			153
-#define KEY_qq			154
-#define KEY_qr			155
-#define KEY_quotemeta		156
-#define KEY_qw			157
-#define KEY_qx			158
-#define KEY_rand		159
-#define KEY_read		160
-#define KEY_readdir		161
-#define KEY_readline		162
-#define KEY_readlink		163
-#define KEY_readpipe		164
-#define KEY_recv		165
-#define KEY_redo		166
-#define KEY_ref			167
-#define KEY_rename		168
-#define KEY_require		169
-#define KEY_reset		170
-#define KEY_return		171
-#define KEY_reverse		172
-#define KEY_rewinddir		173
-#define KEY_rindex		174
-#define KEY_rmdir		175
-#define KEY_s			176
-#define KEY_say			177
-#define KEY_scalar		178
-#define KEY_seek		179
-#define KEY_seekdir		180
-#define KEY_select		181
-#define KEY_semctl		182
-#define KEY_semget		183
-#define KEY_semop		184
-#define KEY_send		185
-#define KEY_setgrent		186
-#define KEY_sethostent		187
-#define KEY_setnetent		188
-#define KEY_setpgrp		189
-#define KEY_setpriority		190
-#define KEY_setprotoent		191
-#define KEY_setpwent		192
-#define KEY_setservent		193
-#define KEY_setsockopt		194
-#define KEY_shift		195
-#define KEY_shmctl		196
-#define KEY_shmget		197
-#define KEY_shmread		198
-#define KEY_shmwrite		199
-#define KEY_shutdown		200
-#define KEY_sin			201
-#define KEY_sleep		202
-#define KEY_socket		203
-#define KEY_socketpair		204
-#define KEY_sort		205
-#define KEY_splice		206
-#define KEY_split		207
-#define KEY_sprintf		208
-#define KEY_sqrt		209
-#define KEY_srand		210
-#define KEY_stat		211
-#define KEY_state		212
-#define KEY_study		213
-#define KEY_sub			214
-#define KEY_substr		215
-#define KEY_symlink		216
-#define KEY_syscall		217
-#define KEY_sysopen		218
-#define KEY_sysread		219
-#define KEY_sysseek		220
-#define KEY_system		221
-#define KEY_syswrite		222
-#define KEY_tell		223
-#define KEY_telldir		224
-#define KEY_tie			225
-#define KEY_tied		226
-#define KEY_time		227
-#define KEY_times		228
-#define KEY_tr			229
-#define KEY_truncate		230
-#define KEY_uc			231
-#define KEY_ucfirst		232
-#define KEY_umask		233
-#define KEY_undef		234
-#define KEY_unless		235
-#define KEY_unlink		236
-#define KEY_unpack		237
-#define KEY_unshift		238
-#define KEY_untie		239
-#define KEY_until		240
-#define KEY_use			241
-#define KEY_utime		242
-#define KEY_values		243
-#define KEY_vec			244
-#define KEY_wait		245
-#define KEY_waitpid		246
-#define KEY_wantarray		247
-#define KEY_warn		248
-#define KEY_when		249
-#define KEY_while		250
-#define KEY_write		251
-#define KEY_x			252
-#define KEY_xor			253
-#define KEY_y			254
+#define KEY_isa			110
+#define KEY_join		111
+#define KEY_keys		112
+#define KEY_kill		113
+#define KEY_last		114
+#define KEY_lc			115
+#define KEY_lcfirst		116
+#define KEY_le			117
+#define KEY_length		118
+#define KEY_link		119
+#define KEY_listen		120
+#define KEY_local		121
+#define KEY_localtime		122
+#define KEY_lock		123
+#define KEY_log			124
+#define KEY_lstat		125
+#define KEY_lt			126
+#define KEY_m			127
+#define KEY_map			128
+#define KEY_mkdir		129
+#define KEY_msgctl		130
+#define KEY_msgget		131
+#define KEY_msgrcv		132
+#define KEY_msgsnd		133
+#define KEY_my			134
+#define KEY_ne			135
+#define KEY_next		136
+#define KEY_no			137
+#define KEY_not			138
+#define KEY_oct			139
+#define KEY_open		140
+#define KEY_opendir		141
+#define KEY_or			142
+#define KEY_ord			143
+#define KEY_our			144
+#define KEY_pack		145
+#define KEY_package		146
+#define KEY_pipe		147
+#define KEY_pop			148
+#define KEY_pos			149
+#define KEY_print		150
+#define KEY_printf		151
+#define KEY_prototype		152
+#define KEY_push		153
+#define KEY_q			154
+#define KEY_qq			155
+#define KEY_qr			156
+#define KEY_quotemeta		157
+#define KEY_qw			158
+#define KEY_qx			159
+#define KEY_rand		160
+#define KEY_read		161
+#define KEY_readdir		162
+#define KEY_readline		163
+#define KEY_readlink		164
+#define KEY_readpipe		165
+#define KEY_recv		166
+#define KEY_redo		167
+#define KEY_ref			168
+#define KEY_rename		169
+#define KEY_require		170
+#define KEY_reset		171
+#define KEY_return		172
+#define KEY_reverse		173
+#define KEY_rewinddir		174
+#define KEY_rindex		175
+#define KEY_rmdir		176
+#define KEY_s			177
+#define KEY_say			178
+#define KEY_scalar		179
+#define KEY_seek		180
+#define KEY_seekdir		181
+#define KEY_select		182
+#define KEY_semctl		183
+#define KEY_semget		184
+#define KEY_semop		185
+#define KEY_send		186
+#define KEY_setgrent		187
+#define KEY_sethostent		188
+#define KEY_setnetent		189
+#define KEY_setpgrp		190
+#define KEY_setpriority		191
+#define KEY_setprotoent		192
+#define KEY_setpwent		193
+#define KEY_setservent		194
+#define KEY_setsockopt		195
+#define KEY_shift		196
+#define KEY_shmctl		197
+#define KEY_shmget		198
+#define KEY_shmread		199
+#define KEY_shmwrite		200
+#define KEY_shutdown		201
+#define KEY_sin			202
+#define KEY_sleep		203
+#define KEY_socket		204
+#define KEY_socketpair		205
+#define KEY_sort		206
+#define KEY_splice		207
+#define KEY_split		208
+#define KEY_sprintf		209
+#define KEY_sqrt		210
+#define KEY_srand		211
+#define KEY_stat		212
+#define KEY_state		213
+#define KEY_study		214
+#define KEY_sub			215
+#define KEY_substr		216
+#define KEY_symlink		217
+#define KEY_syscall		218
+#define KEY_sysopen		219
+#define KEY_sysread		220
+#define KEY_sysseek		221
+#define KEY_system		222
+#define KEY_syswrite		223
+#define KEY_tell		224
+#define KEY_telldir		225
+#define KEY_tie			226
+#define KEY_tied		227
+#define KEY_time		228
+#define KEY_times		229
+#define KEY_tr			230
+#define KEY_truncate		231
+#define KEY_uc			232
+#define KEY_ucfirst		233
+#define KEY_umask		234
+#define KEY_undef		235
+#define KEY_unless		236
+#define KEY_unlink		237
+#define KEY_unpack		238
+#define KEY_unshift		239
+#define KEY_untie		240
+#define KEY_until		241
+#define KEY_use			242
+#define KEY_utime		243
+#define KEY_values		244
+#define KEY_vec			245
+#define KEY_wait		246
+#define KEY_waitpid		247
+#define KEY_wantarray		248
+#define KEY_warn		249
+#define KEY_when		250
+#define KEY_while		251
+#define KEY_write		252
+#define KEY_x			253
+#define KEY_xor			254
+#define KEY_y			255
 
 /* Generated from:
- * db0472e0ad4f44bd0816cad799d63b60d1bbd7e11cef40ea15bf0d00f69669f6 regen/keywords.pl
+ * f77998a5bc995c1b42d3d080de227ef5f11638bcd329367431d8f193aef2d3cc regen/keywords.pl
  * ex: set ro: */