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/*
Copyright (C) 2021- The University of Notre Dame
This software is distributed under the GNU General Public License.
See the file COPYING for details.
*/
#include "jx_sub.h"
#include "jx_function.h"
#include <assert.h>
#include <string.h>
static struct jx * jx_sub_call( struct jx *func, struct jx *args, struct jx *ctx) {
assert(func);
assert(args);
assert(jx_istype(args, JX_ARRAY));
assert(jx_istype(func, JX_SYMBOL));
struct jx *left = jx_copy(func);
struct jx *right = jx_function_sub(func->u.symbol_name, args, ctx);
return jx_operator(JX_OP_CALL, left, right);
}
static struct jx * jx_sub_operator( struct jx_operator *o, struct jx *context )
{
if(!o) return 0;
struct jx *left = NULL;
struct jx *right = NULL;
if (o->type == JX_OP_CALL) return jx_sub_call(o->left, o->right, context);
left = jx_sub(o->left, context);
if (jx_istype(left, JX_ERROR)) {
return left;
}
right = jx_sub(o->right, context);
if (jx_istype(right, JX_ERROR)) {
jx_delete(left);
return right;
}
return jx_operator(o->type, left, right);
}
static struct jx_item *jx_sub_comprehension( struct jx *body, struct jx_comprehension *comp, struct jx *context) {
assert(body);
assert(comp);
// for item
struct jx *value = NULL;
// for comp
struct jx *elements = NULL;
struct jx *condition = NULL;
struct jx_comprehension *next = NULL;
elements = jx_sub(comp->elements, context);
if (jx_istype(elements, JX_ERROR)) {
return jx_item(elements, NULL);
}
// use local var without affecting context, this way we avoid collisions with pairs already in context
// set variable to null value (base case), so jx_sub() knows to not fill in symbols
struct jx *ctx = jx_copy(context);
jx_insert(ctx, jx_string(comp->variable), jx_null());
if (comp->condition) {
condition = jx_sub(comp->condition, ctx);
if (jx_istype(condition, JX_ERROR)) {
jx_delete(ctx);
jx_delete(elements);
return jx_item(condition, NULL);
}
}
if (comp->next) {
struct jx_item *item = jx_sub_comprehension(body, comp->next, ctx);
if (!item) {
jx_delete(ctx);
jx_delete(elements);
jx_delete(condition);
return NULL;
}
next = item->comp;
value = item->value;
free(item);
} else {
// final comp -> do sub on body
value = jx_sub(body, ctx);
if (jx_istype(value, JX_ERROR)) {
jx_delete(ctx);
jx_delete(elements);
jx_delete(condition);
return jx_item(value, NULL);
}
}
jx_delete(ctx);
struct jx_item *result = jx_item(value, 0);
result->comp = jx_comprehension(comp->variable, elements, condition, next);
return result;
}
static struct jx_pair *jx_sub_pair( struct jx_pair *pair, struct jx *context) {
if (!pair) return 0;
return jx_pair(
jx_sub(pair->key, context),
jx_sub(pair->value, context),
jx_sub_pair(pair->next, context));
}
static struct jx_item *jx_sub_item( struct jx_item *item, struct jx *context) {
if (!item) return NULL;
struct jx_item *new_item = NULL;
if (item->comp) {
new_item = jx_sub_comprehension(item->value, item->comp, context);
new_item->next = jx_sub_item(item->next, context);
} else {
new_item = jx_item(jx_sub(item->value, context), jx_sub_item(item->next, context));
}
return new_item;
}
struct jx * jx_sub( struct jx *j, struct jx *context )
{
struct jx *result = NULL;
if (!j) return NULL;
if (context && !jx_istype(context, JX_OBJECT)) {
return jx_error(jx_string("context must be an object"));
}
switch(j->type) {
case JX_SYMBOL: {
struct jx *t = jx_lookup(context, j->u.symbol_name);
if (t) {
if (jx_istype(t, JX_NULL)) {
// for local variables in list comprehensions (don't overwrite)
result = jx_copy(j);
} else {
result = jx_sub(t, context);
}
break;
} else {
return jx_error(jx_format(
"on line %d, %s: undefined symbol",
j->line,
j->u.symbol_name
));
}
}
case JX_DOUBLE:
case JX_BOOLEAN:
case JX_INTEGER:
case JX_STRING:
case JX_ERROR:
case JX_NULL:
result = jx_copy(j);
break;
case JX_ARRAY:
result = jx_array(jx_sub_item(j->u.items, context));
break;
case JX_OBJECT:
result = jx_object(jx_sub_pair(j->u.pairs, context));
break;
case JX_OPERATOR:
result = jx_sub_operator(&j->u.oper, context);
break;
}
return result;
}
/*vim: set noexpandtab tabstop=4: */
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