lib-calc.c

/*
 * Copyright Neil Brown ©2020-2021 <neil@brown.name>
 * May be distributed under terms of GPLv2 - see file:COPYING
 *
 * Perform numeric calculations.
 *
 * 'str' should hold an expression which is computed.
 * It may can contain variables in which can comm2 should produce
 * the contents as a string
 * The result is passed to comm2 in decimal and hex
 */

#include <gmp.h>
#include "core.h"

int do_calc(const char *expr, mpq_t result,
	    bool (*getvar)(const char *name, int len, mpq_t val, void *data),
	    void *data);

static bool getvar(const char *name, int len, mpq_t val, void *data)
{
	struct cmd_info *ci = data;
	char *vnm;
	char *vval;

	if (!ci)
		return False;
	vnm = strnsave(ci->focus, name, len);
	vval = comm_call_ret(strsave, ci->comm2, "get", ci->focus, 0, NULL, vnm);
	if (!vval)
		return False;
	if (do_calc(vval, val, NULL, NULL) != 0)
		return False;
	return True;
}

DEF_CMD(calc)
{
	int ret;
	mpq_t result;
	const char *formats = "xf";

	if (!ci->str || !ci->comm2)
		return Enoarg;
	if (ci->str2)
		formats = ci->str2;
	mpq_init(result);
	ret = do_calc(ci->str, result, getvar, (void*)ci);
	if (ret == 0) {
		/* success */
		if (mpz_cmp_si(mpq_denref(result), 1) == 0) {
			char *buf = mpz_get_str(NULL, 10,
						mpq_numref(result));
			comm_call(ci->comm2, "result", ci->focus, 0, NULL, buf);
			free(buf);
			if (strchr(formats, 'x')) {
				buf = mpz_get_str(NULL, 16, mpq_numref(result));
				comm_call(ci->comm2, "hex-result", ci->focus, 0,
					  NULL, strconcat(ci->focus, "0x",buf));
				free(buf);
			}
			if (strchr(formats, 'X')) {
				buf = mpz_get_str(NULL, -16, mpq_numref(result));
				comm_call(ci->comm2, "hex-result", ci->focus, 0,
					  NULL, strconcat(ci->focus, "0X",buf));
				free(buf);
			}
			if (strchr(formats, 'o')) {
				buf = mpz_get_str(NULL, 8, mpq_numref(result));
				comm_call(ci->comm2, "oct-result", ci->focus, 0,
					  NULL, strconcat(ci->focus, "0o",buf));
				free(buf);
			}
		} else {
			char *buf = NULL;
			mpf_t fl;
			buf = mpq_get_str(NULL, 10, result);
			comm_call(ci->comm2, "frac-result", ci->focus, 0, NULL,
				  buf);
			free(buf);
			if (strchr(formats, 'f')) {
				mpf_init2(fl, 20);
				mpf_set_q(fl, result);
				gmp_asprintf(&buf, "%.10Fg", fl);
				mpf_clear(fl);
				comm_call(ci->comm2, "float-result", ci->focus,
					  0, NULL, buf);
				free(buf);
			}
		}
	} else {
		comm_call(ci->comm2, "err", ci->focus, ret-1);
	}
	mpq_clear(result);
	return ret == 0 ? 1 : Efail;
}

DEF_CMD(calc_replace)
{
	int ret;
	mpq_t result;
	const char *expr = ci->str;
	struct mark *m2 = ci->mark2;
	bool hex = False, oct = False;

	if (ci->num != NO_NUMERIC) {
		/* e.g. from Alt-3 alt-#. Pop up a calc window */
		struct pane *doc = call_ret(pane, "docs:byname", ci->focus,
					    0, NULL, "*Calc*");
		struct pane *p;

		if (!doc)
			doc = call_ret(pane, "doc:from-text", ci->focus,
				       0, NULL, "*Calc*", 0, NULL, "? ");
		if (!doc) {
			call("Message", ci->focus, 0, NULL,
			     "Cannot create *Calc* - sorry");
			return Efail;
		}
		attr_set_str(&doc->attrs, "view-default", "view-calc");
		p = call_ret(pane, "PopupTile", ci->focus, 0, NULL, "MD3tsa");
		if (!p) {
			call("Message", ci->focus, 0, NULL,
			     "Cannot popup *Calc* - sorry");
			return Efail;
		}
		p = home_call_ret(pane, doc, "doc:attach-view", p, 1);
		if (p)
			call("doc:file", p, 1);
		return 1;
	}

	if (!expr) {
		if (!ci->mark)
			return Enoarg;
		/* Try to find a WORD */
		call("doc:WORD", ci->focus, -1, ci->mark);
		m2 = mark_dup(ci->mark);
		call("doc:WORD", ci->focus, 1, m2);
		expr = call_ret(strsave, "doc:get-str", ci->focus, 0, ci->mark, NULL,
				0, m2);
		if (!expr || !*expr)
			return Enoarg;
	}
	mpq_init(result);
	if (expr[0] == '#') {
		hex = True;
		expr += 1;
	} else if (expr[0] == '@') {
		oct = True;
		expr += 1;
	}
	ret = do_calc(expr, result, NULL, NULL);
	if (ret == 0) {
		/* success */
		char buf[100];
		mpf_t fl;

		if (mpz_cmp_si(mpq_denref(result), 1) == 0) {
			gmp_snprintf(buf, sizeof(buf),
				     hex ? "%#Zx" : oct ? "0o%Zo" : "%Zd",
				     mpq_numref(result));
		} else {
			mpf_init(fl);
			mpf_set_q(fl, result);
			gmp_snprintf(buf, sizeof(buf), "%.10Fg", fl);
			mpf_clear(fl);
		}
		if (!ci->mark || !m2 ||
		    call("doc:replace", ci->focus, 0, m2, buf, 0, ci->mark) <= 0)
			call("Message", ci->focus, 0, NULL,
			     strconcat(ci->focus, expr, " -> ", buf));
	} else {
		call("Message", ci->focus, 0, NULL,
		     strconcat(ci->focus, expr, " -> error at ",
			       expr + ret - 1));
	}
	mpq_clear(result);
	return ret == 0 ? 1 : Efail;
}

void edlib_init(struct pane *ed safe)
{
	call_comm("global-set-command", ed, &calc,
		  0, NULL, "CalcExpr");
	call_comm("global-set-command", ed, &calc_replace,
		  0, NULL, "interactive-cmd-calc-replace");
}