symbol.c


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#include <u.h>
#include <libc.h>
#include <bio.h>

#include "apl9.h"

Symtab *globalsymtab;
Symtab *currentsymtab;

Symbol *
getsym(Symtab *tab, Rune *name)
{
	for(int i = 0; i < tab->nsyms; i++)
		if(runestrcmp(tab->syms[i]->name, name) == 0)
			return tab->syms[i];
	
	tab->nsyms++;
	tab->syms = realloc(tab->syms, sizeof(Symbol *) * tab->nsyms);
	tab->syms[tab->nsyms-1] = malloc(sizeof(Symbol));
	tab->syms[tab->nsyms-1]->name = runestrdup(name);
	tab->syms[tab->nsyms-1]->undefined = 1;
	return tab->syms[tab->nsyms-1];
}

Symtab *
newsymtab(void)
{
	Symtab *tab = malloc(sizeof(Symtab));
	tab->nsyms = 0;
	tab->syms = nil;

	Symbol *io = getsym(tab, L"⎕IO");
	io->value.tag = ArrayTag;
	io->value.array = mkscalarint(currentsymtab ? globalIO() : 1);
	io->value.shy = 0;
	io->undefined = 0;

	return tab;
}

void
freesymtab(Symtab *tab)
{
	print("Freeing symtab\n");
	int i;
	for(i = 0; i < tab->nsyms; i++){
		Symbol *s = tab->syms[i];
		if(s->undefined == 0 && s->value.tag == ArrayTag)
			freearray(s->value.array);
	}
	free(tab->syms);
	free(tab);
	print("Done freeing symtab\n");
}

vlong
globalIO(void)
{
	Symbol *s = getsym(currentsymtab, L"⎕IO");
	return s->value.array->intdata[0];
}