Index

This file was automatically generated from http://svn.pugscode.org/pugs/examples/games/hangman.pod on Mon Sep 10 11:50:29 2007 GMT, revision 17733.

sub cls

Explanation of How Hangman Operates

sub cls

Returns nothing.

Checks the magical lexical (S02) $?OS against a junction consisting of 3 values. Use the ternary operator ?? !! to decide what system command to use to clear the screen.

sub get_committer_list

orelse is the low precedence form of // (S03). // is especially useful in its assignment form: 

    $x //= $y;

To summarize, || and or relate to truth, while // and orelse relate to definedness.

Next, we use smart matching, ~~, to skip all of the lines from the beginning of the file which have something other than whitespace.

In the loop that follows: 

    for (=$dict) -> $name {

we use the unary = to perform a readline operation on the filehandle.

sub draw_board

We look over the numbers which are the indices to the elements of the array @letters by forcing the array into numerical context: 

    for (0 .. (+@letters - 1)) -> $i {

Now, ~= might throw you. You Perl 5'ers are seeing the regexp matching operator in reverse. But what you should be seeing is the Perl 6 string concatenation operator (~) followed by an equal sign. Which therefore means that 

  $output ~= @letters[$i];

translates to: 

  $output = $output ~ @letters[$i] ;

sub has_won

In the grep here: 

    @letters == @solution.grep:{ $_ ne '' };

the block beginning with a colon is called an adverbial block. It is equivalent with: 

    grep(@solutions: { $_ ne '' })

In both cases, @solutions is the invocant, and the block is the argument.

sub guess

The loop construction (S04) is used without the the statement modifiers until or <while> which it can take.

sub draw_if_greater_than 

    sub draw_if_greater_than (Str $char, Int $num) returns Bool { 
        ($number_of_bad_guesses >= $num) ?? $char !! ' ';
    }

The character for blank should be a constant, e.g.: 

    my constant $BLANK = ' ';

but it is not implemented yet.

sub draw_hangman

Here we see function interpolation, i.e. the use of { ... } blocks inside strings.

## main loop

Note that the list-context x in Perl 5 is now xx in Perl 6: 

    @solution = ('' xx +@letters);

ERRATA

If you read Apocalypse 03, you will see strong motivation for changing the ternary operator syntax.

AUTHOR

Terrence "metaperl" Brannon

Substantial #perl6 help from 

  mauke, ninereaons, revdiablo, autrijus, stevan