NAME
Physics::Balls::Error - a flagged refusal, returned and never thrown
VERSION
Version 0.06
SYNOPSIS
my $out = Physics::Balls->strike($world, %shot);
if ($out->error) {
print $out->code, ': ', $out->message, "\n";
print "too hard\n" if $out->bad_power;
}DESCRIPTION
Every refusal is one of these, so a caller tests error and reads code rather than parsing a string. The codes are no_ball, bad_direction, bad_power, bad_spin, bad_layout, bad_kind, bad_adjust, bad_roll, overlap and engine, each also a true attribute on the object.
METHODS
of
my $err = Physics::Balls::Error->of('bad_power', 'got 1200');code
The code.
message
The sentence for the code, with the detail after a colon when there is one.
detail
What was wrong, when the refusal can say.
error
Always true.
FLAGS
Each code is also a method that is true on an error of that code and false otherwise, so a caller can test $err->bad_power without comparing strings.
no_ball
The shot names a ball that is not in the layout.
bad_direction
dx and dy must be integers within plus or minus 1,000,000 and not both zero.
bad_power
power must be an integer from 0 to 1000.
bad_spin
sx and sy must be integers from -500 to 500.
bad_layout
A layout is a list of [id, x, y] or [id, x, y, kind] integers with distinct ids.
bad_kind
A row's kind is not an integer index into the kinds the world declares. A world with no kinds accepts kind 0 only.
bad_adjust
The adjust fields are not integers in range: adjust_at any integer, adjust_axis 0 or 1, adjust_dir 1 or -1, adjust_mu and adjust_curve 0 to 100000.
bad_roll
The release roll is not a direction within plus or minus 1,000,000, not both zero, with a spin from 0 to 1000.
overlap
Two balls in the layout are more than a tenth of a millimetre inside each other, at the touching distance of their kinds.
engine
The engine gave up; the detail says why.