Author: lwall
Date: 2009-02-25 02:58:36 +0100 (Wed, 25 Feb 2009)
New Revision: 25536
Modified:
docs/Perl6/Spec/S14-roles-and-parametric-types.pod
Log:
indent examples
Modified: docs/Perl6/Spec/S14-roles-and-parametric-types.pod
===================================================================
--- docs/Perl6/Spec/S14-roles-and-parametric-types.pod 2009-02-24 22:42:08 UTC
(rev 25535)
+++ docs/Perl6/Spec/S14-roles-and-parametric-types.pod 2009-02-25 01:58:36 UTC
(rev 25536)
@@ -409,27 +409,27 @@
wanted to factor out a "greet" method into a role, which takes somebody's name
and greets
them. We want to parameterize it on the greeting.
-role Greet[Str $greeting] {
- method greet() { say "$greeting!"; }
-}
-class EnglishMan does Greet["Hello"] { }
-class Slovak does Greet["Ahoj"] { }
-class Lolcat does Greet["OH HAI"] { }
-EnglishMan.new.greet(); # Hello
-Slovak.new.greet(); # Ahoj
-Lolcat.new.greet(); # OH HAI
+ role Greet[Str $greeting] {
+ method greet() { say "$greeting!"; }
+ }
+ class EnglishMan does Greet["Hello"] { }
+ class Slovak does Greet["Ahoj"] { }
+ class Lolcat does Greet["OH HAI"] { }
+ EnglishMan.new.greet(); # Hello
+ Slovak.new.greet(); # Ahoj
+ Lolcat.new.greet(); # OH HAI
Similarly, we could do a role for requests.
-role Request[Str $statement] {
- method request($object) { say "$statement $object?"; }
-}
-class EnglishMan does Request["Please can I have a"] { }
-class Slovak does Request["Prosim si"] { }
-class Lolcat does Request["I CAN HAZ"] { }
-EnglishMan.new.request("yorkshire pudding");
-Slovak.new.request("borovicka");
-Lolcat.new.request("CHEEZEBURGER");
+ role Request[Str $statement] {
+ method request($object) { say "$statement $object?"; }
+ }
+ class EnglishMan does Request["Please can I have a"] { }
+ class Slovak does Request["Prosim si"] { }
+ class Lolcat does Request["I CAN HAZ"] { }
+ EnglishMan.new.request("yorkshire pudding");
+ Slovak.new.request("borovicka");
+ Lolcat.new.request("CHEEZEBURGER");
Sadly, the Slovak output sucks here. Borovicka is the nominative form of the
word, and we
need to decline it into the accusative case. But some languages don't care
about that, and
@@ -438,27 +438,27 @@
the right one for you. So we write something to produce the accusative case in
Slovak and
pass it in. Here's the new code.
-role Request[Str $statement] {
- method request($object) { say "$statement $object?"; }
-}
-role Request[Str $statement, &transform] {
- method request($object) {
- say "$statement " ~ transform($object) ~ "?";
+ role Request[Str $statement] {
+ method request($object) { say "$statement $object?"; }
}
-}
-module Language::Slovak {
- sub accusative($nom) {
- # ...and before some smartass points it out, I know
- # I'm missing some of the masculine animate declension...
- return $nom.subst(/a$/, 'u');
+ role Request[Str $statement, &transform] {
+ method request($object) {
+ say "$statement " ~ transform($object) ~ "?";
+ }
}
-}
-class EnglishMan does Request["Please can I have a"] { }
-class Slovak does Request["Prosim si", &Language::Slovak::accusative] { }
-class Lolcat does Request["I CAN HAZ"] { }
-EnglishMan.new.request("yorkshire pudding");
-Slovak.new.request("borovicka");
-Lolcat.new.request("CHEEZEBURGER");
+ module Language::Slovak {
+ sub accusative($nom) {
+ # ...and before some smartass points it out, I know
+ # I'm missing some of the masculine animate declension...
+ return $nom.subst(/a$/, 'u');
+ }
+ }
+ class EnglishMan does Request["Please can I have a"] { }
+ class Slovak does Request["Prosim si", &Language::Slovak::accusative] { }
+ class Lolcat does Request["I CAN HAZ"] { }
+ EnglishMan.new.request("yorkshire pudding");
+ Slovak.new.request("borovicka");
+ Lolcat.new.request("CHEEZEBURGER");
Which means we can now properly order our borovicka in Slovakia, which is
awesome. Until
you do it in a loop and find the Headache['very bad'] role got mixed into
yourself
@@ -466,23 +466,23 @@
Role attributes can also be used to initialise attributes:
- role AttrParams[$a, $b] {
- has $.x = $a;
- has $.y = $b;
- }
+ role AttrParams[$a, $b] {
+ has $.x = $a;
+ has $.y = $b;
+ }
...and to constrain types.
- role TypeParams[::T] {
- method x(T $x) { return "got a " ~ T ~ " it was $x" }
- }
+ role TypeParams[::T] {
+ method x(T $x) { return "got a " ~ T ~ " it was $x" }
+ }
- class IntShower does TypeParams[Int] { } # Shows Ints
- class StrShower does TypeParams[Str] { } # Shows Strs
+ class IntShower does TypeParams[Int] { } # Shows Ints
+ class StrShower does TypeParams[Str] { } # Shows Strs
- print IntShower.new.x(42); # Prints 'got a Int it was 42'
- print StrShower.new.x("OH HAI"); # Prints 'got a Str it was OH HAI'
- print IntShower.new.x("OH HAI"); # Dies
+ print IntShower.new.x(42); # Prints 'got a Int it was 42'
+ print StrShower.new.x("OH HAI"); # Prints 'got a Str it was OH HAI'
+ print IntShower.new.x("OH HAI"); # Dies
