void
pgf_print_symbol(PgfSymbol sym, GuWriter *wtr, GuExn *err)
{
switch (gu_variant_tag(sym)) {
case PGF_SYMBOL_CAT: {
PgfSymbolCat* scat = gu_variant_data(sym);
gu_printf(wtr, err, "<%d,%d>", scat->d, scat->r);
break;
}
case PGF_SYMBOL_KS: {
PgfSymbolKS* sks = gu_variant_data(sym);
pgf_print_tokens(sks->tokens, wtr, err);
break;
}
case PGF_SYMBOL_KP: {
PgfSymbolKP* skp = gu_variant_data(sym);
gu_puts("pre {", wtr, err);
pgf_print_tokens(skp->default_form, wtr, err);
for (size_t i = 0; i < skp->n_forms; i++) {
gu_puts("; ", wtr, err);
pgf_print_tokens(skp->forms[i].form, wtr, err);
gu_puts(" / ", wtr, err);
size_t n_prefixes = gu_list_length(skp->forms[i].prefixes);
for (size_t j = 0; j < n_prefixes; j++) {
if (j > 0) gu_putc(' ', wtr, err);
GuString prefix = gu_list_index(skp->forms[i].prefixes, j);
gu_putc('"', wtr, err);
gu_string_write(prefix, wtr, err);
gu_putc('"', wtr, err);
}
}
gu_puts("}", wtr, err);
break;
}
case PGF_SYMBOL_LIT: {
PgfSymbolLit *slit = gu_variant_data(sym);
gu_printf(wtr, err, "{%d,%d}", slit->d, slit->r);
break;
}
case PGF_SYMBOL_VAR: {
PgfSymbolVar *svar = gu_variant_data(sym);
gu_printf(wtr, err, "<%d,$%d>", svar->d, svar->r);
break;
}
default:
gu_impossible();
}
}
PgfApplication*
pgf_expr_unapply(PgfExpr expr, GuPool* pool)
{
int arity = pgf_expr_arity(expr);
if (arity < 0) {
return NULL;
}
PgfApplication* appl = gu_new_flex(pool, PgfApplication, args, arity);
appl->n_args = arity;
for (int n = arity - 1; n >= 0; n--) {
PgfExpr e = pgf_expr_unwrap(expr);
gu_assert(gu_variant_tag(e) == PGF_EXPR_APP);
PgfExprApp* app = gu_variant_data(e);
appl->args[n] = app->arg;
expr = app->fun;
}
PgfExpr e = pgf_expr_unwrap(expr);
gu_assert(gu_variant_tag(e) == PGF_EXPR_FUN);
PgfExprFun* fun = gu_variant_data(e);
appl->fun = fun->fun;
return appl;
}
