use Games::Score; # these three values are the default ones, by the way Games::Score->default_score(0); Games::Score->default_step(1); Games::Score->step_method('inc'); # start two players my $player1 = Games::Score->new(); my $player2 = Games::Score->new(); # set a winning condition Games::Score->victory_is( sub { $_[0] >= 20 } ); # and something to do if it is achieved Games::Score->on_victory_do( sub { print "Won!" } ); # give points to the players $player1->add(2); $player2->step(); # look at section FUNCTIONS for more functionalities, such as Games::Score->invalidate_if( sub { $_[0] > 20 } );
Games::Score can be use to keep track of several players' points in a game, regardless of the starting amount of points, winning and/or losing conditions, etc.
It provides several useful methods so that the user doesn't have to keep testing values to see if they're valid or if the player condition has changed.
new(); new(PLAYERNAME); new(PLAYER_NAME,PLAYER_SCORE);
Creates a new Games::Score object. Default name is "Player" and default score is 0.
# start a player with the default points my $player1 = Games::Score->new(); # start a player named "BANZAI" my $player2 = Games::Score->new("BANZAI"); # start a player named "BANZAI" with 20 points my $player2 = Games::Score->new("BANZAI",20);
victory_is(CODE)
Allows for defining a funtion which, receiving the player's score, will return true if the player has won the game.
This function is used by has_won().
In addition, if both victory_is() and on_victory_do() are defined, as soon as the player's score changes and the victory condition (defined with victory_is()) is verified, the function defined with on_victory_do() is executed.
The function defined with victory_is() receives the score as a parameter.
# set the winning condition to be "score is greater or equal than 20" Games::Score->victory_is( sub { $_[0] >= 20 } )
defeat_is(CODE);
Allows for defining a funtion which, receiving the player's score, will return true if the player has lost the game.
This function is used by has_lost().
In addition, if both defeat_is() and on_defeat_do() are defined, as soon as the player's score changes and the defeat condition (defined with defeat_is()) is verified, the function defined with on_defeat_do() is executed.
The function defined with defeat_is() receives the score as a parameter.
# set the winning condition to be "score is negative" Games::Score->defeat_is( sub { $_[0] < 0 } )
on_victory_do(CODE);
This method lets you define a function that will be called as soon as has_won() starts returning a true value. In other words, when the score changes and the function defined with is_victory() returns true, the function defined with on_victory_do() is called.
The function receives as parameters the score of the player and its name.
# set a new condition for on_victory_do() our $game_ended; Games::Score->on_victory_do( sub { $game_ended = 1 } ); # assuming this: my $player1 = Games::Score->new(); Games::Score->victory_is( sub { $_[0] == 1 } ); # the following line will trigger sub { $game_ended = 1 } $player1->score(1);
on_defeat_do(CODE);
This method lets you define a function that will be called as soon as has_lost() starts returning a true value. In other words, when the score changes and the function defined with is_defeat() returns true, the function defined with on_defeat_do() is called.
# set a new condition for on_defeat_do() our $game_ended; Games::Score->on_defeat_do( sub { $game_ended = 1 } ); # assuming this: my $player1 = Games::Score->new(); Games::Score->defeat_is( sub { $_[0] == -1 } ); # the following line will trigger sub { $game_ended = 1 } $player1->score(-1);
has_won();
Returns true if the function defined with victory_is() returns true;
if ($player1->has_won()) { print "$player1->name() has won"; }
has_lost();
Returns true if the function defined with defeat_is() returns true;
if ($player1->has_lost()) { print "$player1->name() has lost"; }
is_ok();
Returns true if the player hasn't won or lost.
# keep playing until player either wins or loses while ($player1->is_ok()) { # your game code here }
add(NUMBER); add(NUMBER, NUMBER, ...);
Give X points to the player (this always increases, regardless of step_method()).
# player1 gets 5 more points $player1->add(5); # player1 gets 2, 3 and 4 more points $player1->add(2,3,4);
subtract(NUMBER); subtract(NUMBER, NUMBER, ...);
Take X points from the player (this always decreases, regardless of step_method()).
# player1 loses 5 points $player1->subtract(5); # player1 loses 2, 3 and 4 more points $player1->subtract(2,3,4);
invalidate_if(CODE);
When the score is about to change, score doesn't change if the function defined with invalidate_if() returns true.
# sets the condition so that negative values are not allowed Games::Score->invalidate_if( sub { $_[0] < 0 } ); # here's an example of how this works: Games::Score->invalidate_if( sub { $_[0] < 0 } ); my $player1 = Games::Score->new(); $player1->score(3); # this line subtracts the player's score by 2 $player1->subtract(2); # this one doesn't, as his score is already 1 and the result would be # invalid $player1->subtract(2);
If one is, for instance, adding several numbers to the score, no more numbers are added as soon as the score can be invalidated.
# assuming the same configuration as before: Games::Score->invalidate_if( sub { $_[0] > 20 } ); my $player1 = Games::Score->new(); $player1->score(18); # the following line adds 1 point to the score, doesn't add 2 more as # that would take the score up do 21, and skips the rest of the # instruction, even though it wouldn't invalidate anything by itself $player1->add(1,2,1);
To remove the condition, assign it an empty function
# assign an empty function to victory_if Games::Score->invalidate_if( sub { } );
step_method(); step_method('inc'); step_method('dec');
Defines whether the set() method increases or decreases score; possible values are 'inc' (increase) and 'dec' (decrease). Assigning multiple values stops at the first valid one. Default value is 'inc', increase.
# step method is inc (increase) Games::Score->step_method('inc'); # step method is dec (decrease) Games::Score->step_method('dec'); # check the step method my $step_method = Games::Score->step_method();
default_step(); default_step(NUMBER);
Set or check the default number of points the step() method uses. Assigning multiple values makes the last of them to be it. Default value is 1.
# step() function now increases (or decreases, see step_method()) in # 2 points Games::Score->default_step(2); # check the default_step my $default_step = Games::Score->default_step();
step(); step(NUMBER);
The basic operation to change score. Default is "add one point"; that can be changed with default_step() and method().
# the score from player1 steps once $player1->step; # the score from player1 steps twice $player1->step(2);
default_score(); default_score(NUMBER);
Set or check the default score with which new players start. Default is 0.
# all players start with 301 points Games::Score->default_score(301); # check the default_score my $default_score = Games::Score->default_score();
priority_is(); priority_is('win'); priority_is('lose'); priority_is('win_lose'); priority_is('lose_win');
Get or set the priority for actions involving winning or losing.
Possible values are:
If the player wins and loses at the same time, only the action for defeat is run.
If the player wins and loses at the same time, only the action for victory is run.
If the player wins and loses at the same time, the action for victory is run first and than the action for defeat is run too.
If the player wins and loses at the same time, the action for defeat is run first and than the action for victory is run too.
Default_value is 'lose'.
# Assuming this configuration Games::Score->on_victory_do( sub { "You won!" } ); Games::Score->on_defeat( sub { "You lost!" } ); # The following line states that if the player wins and loses at the # same time, he loses Games::Score->priority_is('lose');
score(); score(NUMBER); score(NUMBER, NUMBER, ...);
Get or set the score of the player. Assigning multiple values goes through all of them, skipping when invalidate_if() returns true, and stopping at the last one. Default score is 0.
# get the score of the player my $score = $player->score(); # player now has 10 points $player->score(10);
default_name(); default_name(DEFAULT_NAME);
Set or check the default name with which new players start. Default name is 'Player'.
# all players are by default named "PLAYER" Games::Score->default_name("PLAYER"); # check the default_name my $default_name = Games::Score->default_name();
name(); name(NEW_NAME);
Get or set the name of the player. Default name is 'Player', which can be changed with default_name().
# get the name of the player my $name = $player->name(); # player is now named "WARRIOR" $player->name("WARRIOR");
Please note the following: if you happen to have two players, change the score for both of them and both of them get in the same situation (victory, for instance), one of them is going to have his on_victory_do() function (if defined) run before the other one.
Always consider the possibility of draws in your game with disregard to Games::Score (at least for now).
Example of a game where users start with 0 points and win as soon as they get more than 20 points. There is no way of losing.
# These two lines aren't actually needed, as these are the default # values Games::Score->default_score(0); Games::Score->step_method('inc'); # Set the victory condition Games::Score->victory_is( sub { $_[0] > 20; } ); # Set what to do on victory our $game_ended = 0; our $message = ''; Games::Score->on_victory_do( sub { $game_ended = 1; $message = "$_[1] has won!\n"; } ); # Start two players, "Shiribi" and "Zuncucu" my $player1 = Games::Score->new("Shiribi"); my $player2 = Games::Score->new("Zuncucu"); my @players = ($player1, $player2); # And have a random game until ($game_ended) { for (@players) { if (rand(1)) { $_->step(); print "Player $_->name() scored ", "and now has $_->score() point(s).\n"; last if $_->has_won(); } else { print "Player $_->name() didn't score.\n" } } }
Example of a game where users start with 301 points, always lose points instead of gaining them, and win when they reach 0 points. Getting less than 0 points invalidates the score update.
# default score is 301, points decrease, winning on 0, negative score # disallowed Games::Score->default_score(301); Games::Score->step_method('dec'); Games::Score->invalidate_if( sub { $_[0] < 0 } ); Games::Score->victory_is( sub { $_[0] == 0 } );
Jose Castro, <cog@cpan.org>
Copyright 2004 Jose Castro, All Rights Reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
To install Games::Score, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Games::Score
CPAN shell
perl -MCPAN -e shell install Games::Score
For more information on module installation, please visit the detailed CPAN module installation guide.