#!/usr/local/bin/rune -x
#
# Test floating point iterations via File.format.  Caller should generally
# grep for 'Final'.  Our increments purposefully do not divide nicely into
# a base-2 FP representation, so errors will build up.

import "sys";
import <stdio>;

alias stdio.File *stdout = stdio.stdout;

public
int
main(int ac, char **av)
{
	# The iteration with floats will work but the error is so
	# large an extra 44 loops will occur.
	#
	float_test();

	# With doubles it has enough precision and we can get an idea
	# of the error that built up.
	#
	double_test();

	# With ldoubles it definitely has enough, and the error is
	# significantly lower.
	#
	ldouble_test();
}

void
float_test()
{
	float	iter;
	int count;

	for (iter = 0.0F; iter < 100.0F; iter += 0.001F) {
		stdout->format("Iteration %7.3f\n", iter);
		++count;
	}
	stdout->format("Final count=%d fullprec %1.16f\n", count, iter);
}

void
double_test()
{
	double	iter;
	int count;

	for (iter = 0.0; iter < 100.0; iter += 0.001) {
		stdout->format("Iteration %7.3f\n", iter);
		++count;
	}
	stdout->format("Final count=%d fullprec %1.16f\n", count, iter);
}

void
ldouble_test()
{
	ldouble	iter;
	int count;

	for (iter = 0.0X; iter < 100.0X; iter += 0.001X) {
		stdout->format("Iteration %7.3f\n", iter);
		++count;
	}
	stdout->format("Final count=%d fullprec %1.16f\n", count, iter);
}