gnucash/libgnucash/app-utils/gnc-euro.c
John Ralls e0300d3a62 Replace the gnc:numeric pair with normal Scheme rationals.
This allows direct conversion between Scheme numbers and gnc_numeric
without the performance or accuracy penalties arising from using doubles
as an intermediary.
2017-12-21 15:33:15 -08:00

235 lines
7.5 KiB
C

/********************************************************************\
* gnc-euro.c -- utilities for EURO currency *
* *
* Copyright (C) 2000 Herbert Thoma *
* *
* This program is free software; you can redistribute it and/or *
* modify it under the terms of the GNU General Public License as *
* published by the Free Software Foundation; either version 2 of *
* the License, or (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License*
* along with this program; if not, write to the Free Software *
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. *
* *
\********************************************************************/
#include <config.h>
#include "gnc-euro.h"
#include <glib/gi18n.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include "gnc-ui-util.h"
/* local structs */
typedef struct
{
const char *currency;
double rate;
} gnc_euro_rate_struct;
/* This array MUST be sorted ! */
/* The rates are per EURO */
static gnc_euro_rate_struct gnc_euro_rates[] =
{
{ "ATS", 13.7603 }, /* austrian schilling */
{ "BEF", 40.3399 }, /* belgian franc */
{ "BFR", 40.3399 }, /* belgian franc */
{ "CYP", .585274 }, /* cyprus pound */
{ "DEM", 1.95583 }, /* german mark */
{ "DM", 1.95583 }, /* german mark */
{ "EEK", 15.6466 }, /* Estonian Kroon */
{ "ESC", 200.482 }, /* portugese escudo */
{ "ESP", 166.386 }, /* spanish peseta */
{ "EUR", 1.00000 }, /* euro */
{ "EURO", 1.00000 }, /* euro */
{ "FF", 6.55957 }, /* french franc */
{ "FIM", 5.94573 }, /* finnmark */
{ "FMK", 5.94573 }, /* finnmark */
{ "FRF", 6.55957 }, /* french franc */
{ "GRD", 340.750 }, /* greek drachma */
{ "HFL", 2.20371 }, /* netherland gulden */
{ "IEP", .787564 }, /* irish pound */
{ "IRP", .787564 }, /* irish pound */
{ "ITL", 1936.27 }, /* italian lira */
{ "LFR", 40.3399 }, /* luxembourg franc */
{ "LIT", 1936.27 }, /* italian lira */
{ "LUF", 40.3399 }, /* luxembourg franc */
{ "LVL", .702804 }, /* latvian lats */
{ "MTL", .429300 }, /* maltese lira */
{ "NLG", 2.20371 }, /* netherland gulden */
{ "PTA", 166.386 }, /* spanish peseta */
{ "PTE", 200.482 }, /* portugese escudo */
{ "S", 13.7603 }, /* austrian schilling */
{ "SCH", 13.7603 }, /* austrian schilling */
{ "SIT", 239.640 }, /* slovenian tolar */
{ "SKK", 30.1260 } /* slovak koruna */
};
static int
gnc_euro_rate_compare (const void * key, const void * value)
{
const gnc_commodity * curr = key;
const gnc_euro_rate_struct * euro = value;
if (!key || !value)
return -1;
return g_ascii_strcasecmp(gnc_commodity_get_mnemonic(curr), euro->currency);
}
#if 0 /* Not Used */
static int
gnc_euro_rate_compare_code (const void * key, const void * value)
{
const char *code = key;
const gnc_euro_rate_struct * euro = value;
if (!key || !value)
return -1;
return g_ascii_strcasecmp (code, euro->currency);
}
#endif
/* ------------------------------------------------------ */
gboolean
gnc_is_euro_currency(const gnc_commodity * currency)
{
gnc_euro_rate_struct *result;
if (currency == NULL)
return FALSE;
if (!gnc_commodity_is_iso(currency))
return FALSE;
result = bsearch(currency,
gnc_euro_rates,
sizeof(gnc_euro_rates) / sizeof(gnc_euro_rate_struct),
sizeof(gnc_euro_rate_struct),
gnc_euro_rate_compare);
if (result == NULL)
return FALSE;
return TRUE;
}
/* ------------------------------------------------------ */
gnc_numeric
gnc_convert_to_euro(const gnc_commodity * currency, gnc_numeric value)
{
gnc_euro_rate_struct *result;
if (currency == NULL)
return gnc_numeric_zero ();
if (!gnc_commodity_is_iso(currency))
return gnc_numeric_zero ();
result = bsearch(currency,
gnc_euro_rates,
sizeof(gnc_euro_rates) / sizeof(gnc_euro_rate_struct),
sizeof(gnc_euro_rate_struct),
gnc_euro_rate_compare);
if (result == NULL)
return gnc_numeric_zero ();
/* round to 2 decimal places */
{
gnc_numeric rate;
rate = double_to_gnc_numeric (result->rate, 100000, GNC_HOW_RND_ROUND_HALF_UP);
/* EC Regulation 1103/97 states we should use "Round half away from zero"
* See http://europa.eu/legislation_summaries/economic_and_monetary_affairs/institutional_and_economic_framework/l25025_en.htm */
return gnc_numeric_div (value, rate, 100, GNC_HOW_RND_ROUND_HALF_UP);
}
}
/* ------------------------------------------------------ */
gnc_numeric
gnc_convert_from_euro(const gnc_commodity * currency, gnc_numeric value)
{
gnc_euro_rate_struct * result;
if (currency == NULL)
return gnc_numeric_zero ();
if (!gnc_commodity_is_iso(currency))
return gnc_numeric_zero ();
result = bsearch(currency,
gnc_euro_rates,
sizeof(gnc_euro_rates) / sizeof(gnc_euro_rate_struct),
sizeof(gnc_euro_rate_struct),
gnc_euro_rate_compare);
if (result == NULL)
return gnc_numeric_zero ();
{
gnc_numeric rate;
rate = double_to_gnc_numeric (result->rate, 100000, GNC_HOW_RND_ROUND_HALF_UP);
/* EC Regulation 1103/97 states we should use "Round half away from zero"
* See http://europa.eu/legislation_summaries/economic_and_monetary_affairs/institutional_and_economic_framework/l25025_en.htm */
return gnc_numeric_mul (value, rate, gnc_commodity_get_fraction (currency),
GNC_HOW_RND_ROUND_HALF_UP);
}
}
/* ------------------------------------------------------ */
gnc_numeric
gnc_euro_currency_get_rate (const gnc_commodity *currency)
{
gnc_euro_rate_struct * result;
if (currency == NULL)
return gnc_numeric_zero ();
if (!gnc_commodity_is_iso(currency))
return gnc_numeric_zero ();
result = bsearch(currency,
gnc_euro_rates,
sizeof(gnc_euro_rates) / sizeof(gnc_euro_rate_struct),
sizeof(gnc_euro_rate_struct),
gnc_euro_rate_compare);
if (result == NULL)
return gnc_numeric_zero ();
return double_to_gnc_numeric (result->rate, GNC_DENOM_AUTO,
GNC_HOW_RND_ROUND_HALF_UP);
}
/* ------------------------------------------------------ */
gnc_commodity *
gnc_get_euro (void)
{
gnc_commodity_table *table;
table = gnc_commodity_table_get_table (gnc_get_current_book ());
return gnc_commodity_table_lookup (table, GNC_COMMODITY_NS_CURRENCY, "EUR");
}