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Changes so that user-defined classes can implement operations invoked

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by special syntax: you can now define your own numbers, sequences and
mappings.
This commit is contained in:
Guido van Rossum 1992-08-12 15:35:34 +00:00
parent 423d6c6bca
commit 04691fc1c1
5 changed files with 609 additions and 42 deletions
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106
Python/ceval.c
View file

@ -36,6 +36,9 @@ OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#include "bltinmodule.h"
#include "traceback.h"
/* Turn this on if your compiler chokes on the big switch: */
/* #define CASE_TOO_BIG 1 /**/
#ifndef NDEBUG
/* For debugging the interpreter: */
#define LLTRACE 1 /* Low-level trace feature */
@ -106,13 +109,13 @@ init_save_thread()
dynamically loaded modules needn't be compiled separately for use
with and without threads: */
void *
object *
save_thread()
{
#ifdef USE_THREAD
if (interpreter_lock) {
void *res;
res = (void *)current_frame;
object *res;
res = (object *)current_frame;
current_frame = NULL;
release_lock(interpreter_lock);
return res;
@ -124,7 +127,7 @@ save_thread()
void
restore_thread(x)
void *x;
object *x;
{
#ifdef USE_THREAD
if (interpreter_lock) {
@ -722,6 +725,10 @@ eval_code(co, globals, locals, arg)
if ((err = dict2remove(f->f_locals, w)) != 0)
err_setstr(NameError, getstringvalue(w));
break;
#ifdef CASE_TOO_BIG
default: switch (opcode) {
#endif
case UNPACK_VARARG:
if (EMPTY()) {
@ -1023,13 +1030,19 @@ eval_code(co, globals, locals, arg)
break;
case JUMP_IF_FALSE:
if (!testbool(TOP()))
err = testbool(TOP());
if (err > 0)
err = 0;
else if (err == 0)
JUMPBY(oparg);
break;
case JUMP_IF_TRUE:
if (testbool(TOP()))
err = testbool(TOP());
if (err > 0) {
err = 0;
JUMPBY(oparg);
}
break;
case JUMP_ABSOLUTE:
@ -1092,7 +1105,11 @@ eval_code(co, globals, locals, arg)
err_setstr(SystemError, "eval_code: unknown opcode");
why = WHY_EXCEPTION;
break;
#ifdef CASE_TOO_BIG
}
#endif
} /* switch */
on_error:
@ -1388,22 +1405,27 @@ flushline()
}
/* Test a value used as condition, e.g., in a for or if statement */
/* Test a value used as condition, e.g., in a for or if statement.
Return -1 if an error occurred */
static int
testbool(v)
object *v;
{
int res;
if (v == None)
return 0;
if (v->ob_type->tp_as_number != NULL)
return (*v->ob_type->tp_as_number->nb_nonzero)(v);
if (v->ob_type->tp_as_sequence != NULL)
return (*v->ob_type->tp_as_sequence->sq_length)(v) != 0;
if (v->ob_type->tp_as_mapping != NULL)
return (*v->ob_type->tp_as_mapping->mp_length)(v) != 0;
/* All other objects are 'true' */
return 1;
res = 0;
else if (v->ob_type->tp_as_number != NULL)
res = (*v->ob_type->tp_as_number->nb_nonzero)(v);
else if (v->ob_type->tp_as_mapping != NULL)
res = (*v->ob_type->tp_as_mapping->mp_length)(v);
else if (v->ob_type->tp_as_sequence != NULL)
res = (*v->ob_type->tp_as_sequence->sq_length)(v);
else
res = 0;
if (res > 0)
res = 1;
return res;
}
static object *
@ -1649,7 +1671,13 @@ not(v)
object *v;
{
int outcome = testbool(v);
object *w = outcome == 0 ? True : False;
object *w;
if (outcome < 0)
return NULL;
if (outcome == 0)
w = True;
else
w = False;
INCREF(w);
return w;
}
@ -1780,18 +1808,24 @@ apply_subscript(v, w)
err_setstr(TypeError, "unsubscriptable object");
return NULL;
}
if (tp->tp_as_sequence != NULL) {
if (tp->tp_as_mapping != NULL) {
return (*tp->tp_as_mapping->mp_subscript)(v, w);
}
else {
int i;
if (!is_intobject(w)) {
err_setstr(TypeError, "sequence subscript not int");
return NULL;
}
i = getintvalue(w);
if (i < 0)
i += (*tp->tp_as_sequence->sq_length)(v);
if (i < 0) {
int len = (*tp->tp_as_sequence->sq_length)(v);
if (len < 0)
return NULL;
i += len;
}
return (*tp->tp_as_sequence->sq_item)(v, i);
}
return (*tp->tp_as_mapping->mp_subscript)(v, w);
}
static object *
@ -1841,6 +1875,8 @@ apply_slice(u, v, w) /* return u[v:w] */
}
ilow = 0;
isize = ihigh = (*tp->tp_as_sequence->sq_length)(u);
if (isize < 0)
return NULL;
if (slice_index(v, isize, &ilow) != 0)
return NULL;
if (slice_index(w, isize, &ihigh) != 0)
@ -1858,7 +1894,11 @@ assign_subscript(w, key, v) /* w[key] = v */
sequence_methods *sq;
mapping_methods *mp;
int (*func)();
if ((sq = tp->tp_as_sequence) != NULL &&
if ((mp = tp->tp_as_mapping) != NULL &&
(func = mp->mp_ass_subscript) != NULL) {
return (*func)(w, key, v);
}
else if ((sq = tp->tp_as_sequence) != NULL &&
(func = sq->sq_ass_item) != NULL) {
if (!is_intobject(key)) {
err_setstr(TypeError,
@ -1867,15 +1907,15 @@ assign_subscript(w, key, v) /* w[key] = v */
}
else {
int i = getintvalue(key);
if (i < 0)
i += (*sq->sq_length)(w);
if (i < 0) {
int len = (*sq->sq_length)(w);
if (len < 0)
return -1;
i += len;
}
return (*func)(w, i, v);
}
}
else if ((mp = tp->tp_as_mapping) != NULL &&
(func = mp->mp_ass_subscript) != NULL) {
return (*func)(w, key, v);
}
else {
err_setstr(TypeError,
"can't assign to this subscripted object");
@ -1899,6 +1939,8 @@ assign_slice(u, v, w, x) /* u[v:w] = x */
}
ilow = 0;
isize = ihigh = (*sq->sq_length)(u);
if (isize < 0)
return -1;
if (slice_index(v, isize, &ilow) != 0)
return -1;
if (slice_index(w, isize, &ihigh) != 0)
@ -1955,6 +1997,8 @@ cmp_member(v, w)
return -1;
}
n = (*sq->sq_length)(w);
if (n < 0)
return -1;
for (i = 0; i < n; i++) {
x = (*sq->sq_item)(w, i);
cmp = cmpobject(v, x);
@ -1977,7 +2021,7 @@ cmp_outcome(op, v, w)
case IS:
case IS_NOT:
res = (v == w);
if (op == IS_NOT)
if (op == (int) IS_NOT)
res = !res;
break;
case IN:
@ -1985,7 +2029,7 @@ cmp_outcome(op, v, w)
res = cmp_member(v, w);
if (res < 0)
return NULL;
if (op == NOT_IN)
if (op == (int) NOT_IN)
res = !res;
break;
case EXC_MATCH: