Distinguishing reference types and iterating over object properties #43
Description
Hi, i am trying to write native printing function, which takes any kind of JS value and prints it out, recursing into arrays and objects, also wrapping strings into quotes.
This is what i came up with:
UPD1: replaced flag checking with mxIsFunction, xsTypeOf with mxIs* and fxIs* functions, started taking into account String() object as well as primitive strings. Old version is at https://gist.github.com/iamtakingiteasy/ce4ffe33674d56234c446fc73c401998
#include <xs/xsAll.h>
#include <xs.h>
#include <stdio.h>
void hinarin_root_print(xsMachine *the) {
for (xsIntegerValue i = 0; i < xsToInteger(xsArgc); i++) {
if (i > 0) {
printf(" ");
}
txSlot *instance = &xsArg(i);
if (mxIsReference(instance)) {
txSlot *reference = instance->value.reference;
if (fxIsArray(the, reference)) { // seems OK, but why fx* and not mx* ?
printf("[");
for (txIndex d = 0; d < reference->next->value.array.length; d++) {
if (d > 0) {
printf(", ");
}
xsCallFunction1(xsGet(xsGlobal, xsID("print")), xsNull, reference->next->value.array.address[d]);
}
printf("]");
} else if (reference->next == NULL) { // is this a correct way to detect plain {} object?
printf("{");
for (txSlot *next = reference->next; next; next = next->next) { // is this a correct way to iterate over object properties?
if (next != reference->next) {
printf(", ");
}
printf("%s: ", xsName(next->ID));
xsCallFunction1(xsGet(xsGlobal, xsID("print")), xsNull, *next);
}
printf("}");
} else if (mxIsFunction(reference)) {
char *name = "";
if (reference->next->ID != XS_NO_ID) {
name = xsName(reference->next->ID); //appears to be a function name
}
printf("function %s() { ... }", name);
} else if (mxIsString(reference)) {
printf("\"%s\"", reference->next->value.string);
} else {
printf("%s", xsToString(*instance));
}
} else if (mxIsStringPrimitive(instance)) {
printf("\"%s\"", instance->value.string);
} else {
printf("%s", xsToString(*instance));
}
}
}
void hinarin_root_println(xsMachine *the) {
hinarin_root_print(the);
printf("\n");
}
void hinarin_bind_root(xsMachine *the) {
xsDefine(xsGlobal, xsID("print"), xsNewHostFunction(hinarin_root_print, 1), xsChangeAll);
xsDefine(xsGlobal, xsID("println"), xsNewHostFunction(hinarin_root_println, 1), xsChangeAll);
}but I have a few questions, which are outlined in comments to code, thanks.
Also: what XS_STRING_X_KIND and XS_CODE_X_KIND kinds are meaning and how they are different from XS_STRING_KIND and XS_CODE_KIND kinds? And i see that it is possible to get number of function arguments: reference->next->next->next->value.integer, but is it possible to get function argument names?
P.S. Any hints on how to do common things and what can be done better with XS6 are also quite welcome.