Merge remote-tracking branch 'upstream/master'

1 files changed, 362 insertions, 247 deletions

diff --git a/perl6.html.markdown b/perl6.html.markdown
index 92219708..fe5b197c 100644
--- a/perl6.html.markdown
+++ b/perl6.html.markdown
@@ -7,48 +7,57 @@ contributors:
     - ["Nami-Doc", "http://github.com/Nami-Doc"]
 ---
 
-Perl 6 is a highly capable, feature-rich programming language made for the upcoming hundred years.
+Perl 6 is a highly capable, feature-rich programming language made for the
+upcoming hundred years.
 
-Perl 6 runs on [the Parrot VM](http://parrot.org/), the JVM and [the MoarVM](http://moarvm.com).
+Perl 6 runs on [the Parrot VM](http://parrot.org/), the JVM
+and [the MoarVM](http://moarvm.com).
+
+Meta-note : the triple pound signs are here to denote headlines,
+double paragraphs, and single notes.
 
-Meta-note : the triple pound signs are here to denote headlines, double paragraphs, single notes.
 `#=>` represents the output of a command.
 
 ```perl
 # Single line comment start with a pound
 
 #`(
-  Multiline comments use #` and a quoting construct. (), [], {}, 「」, etc, will work.
+  Multiline comments use #` and a quoting construct.
+  (), [], {}, 「」, etc, will work.
 )
 
 ### Variables
 
 # In Perl 6, you declare a lexical variable using `my`
-a
-# Perl 6 has 4 variable types :
+my $variable;
+# Perl 6 has 4 kinds of variables:
 
 ## * Scalars. They represent a single value. They start with a `$`
 
 my $str = 'String';
 my $str2 = "String"; # double quotes allow for interpolation
 
-# variable names can contain but not end with simple quotes and dashes, and can contain (and end with) underscores :
+# variable names can contain but not end with simple quotes and dashes,
+#  and can contain (and end with) underscores :
 # my $weird'variable-name_ = 5; # works !
 
 my $bool = True; # `True` and `False` are Perl 6's boolean
 my $inverse = !$bool; # You can invert a bool with the prefix `!` operator
-my $forced-bool = so $str; # And you can use the prefix `so` operator which turns its operand into a Bool
+my $forced-bool = so $str; # And you can use the prefix `so` operator
+                           # which turns its operand into a Bool
 
 ## * Arrays. They represent multiple values. Their name start with `@`.
 
 my @array = 1, 2, 3;
 my @array = 'a', 'b', 'c';
 # equivalent to :
-my @array = <a b c>; # array of words, delimited by space. similar to perl5's qw, or Ruby's %w
+my @array = <a b c>; # array of words, delimited by space.
+                     # Similar to perl5's qw, or Ruby's %w.
 
 say @array[2]; # Array indices start at 0 -- This is the third element
 
-say "Interpolate an array using [] : @array[]"; #=> Interpolate an array using [] : a b c
+say "Interpolate an array using [] : @array[]";
+#=> Interpolate an array using [] : a b c
 
 ## * Hashes. Key-Value Pairs.
 # Hashes are actually arrays of Pairs (`Key => Value`),
@@ -58,10 +67,12 @@ my %hash = 1 => 2,
 my %hash = autoquoted => "key", # keys *can* get auto-quoted
             "some other" => "value", # trailing commas are okay
             ;
-my %hash = <key1 value1 key2 value2>; # you can also create a hash from an even-numbered array
+my %hash = <key1 value1 key2 value2>; # you can also create a hash
+                                      # from an even-numbered array
 my %hash = key1 => 'value1', key2 => 'value2'; # same as this
 
-# You can also use the "colon pair" syntax: (especially handy for named parameters that you'll see later)
+# You can also use the "colon pair" syntax:
+# (especially handy for named parameters that you'll see later)
 my %hash = :w(1), # equivalent to `w => 1`
            # this is useful for the `True` shortcut:
            :truey, # equivalent to `:truey(True)`, or `truey => True`
@@ -70,33 +81,37 @@ my %hash = :w(1), # equivalent to `w => 1`
            ;
 
 say %hash{'key1'}; # You can use {} to get the value from a key
-say %hash<key2>; # if it's a string, you can actually use <>
+say %hash<key2>;   # If it's a string, you can actually use <>
+                   # (`{key1}` doesn't work, as Perl6 doesn't have barewords)
 
-## * Subs (subroutines, or functions in most other languages). Stored in variable, they use `&`
+## * Subs (subroutines, or functions in most other languages).
+# Stored in variable, they use `&`.
 sub say-hello { say "Hello, world" }
 
-sub say-hello-to(Str $name) { # you can provide the type of an argument
-                              # and it'll be checked at compile-time
+sub say-hello-to(Str $name) { # You can provide the type of an argument
+                              # and it'll be checked at compile-time.
 
     say "Hello, $name !";
 }
 
-# since you can omit parenthesis to call a function with no arguments,
-#  you need "&" in the name to capture `say-hello`
+# Since you can omit parenthesis to call a function with no arguments,
+#  you need "&" in the name to capture `say-hello`.
 my &s = &say-hello;
-my &other-s = sub { say "anonymous function !" }
+my &other-s = sub { say "Anonymous function !" }
 
 # A sub can have a "slurpy" parameter, or "doesn't-matter-how-many"
-sub as-many($head, *@rest) { # the `*@` slurpy will basically "take everything else".
-                             # Note: you can have parameters *before* (like here) a slurpy one,
-                             # but not *after*.
+sub as-many($head, *@rest) { # `*@` (slurpy) will basically "take everything else".
+                             # Note: you can have parameters *before* (like here)
+                             # a slurpy one, but not *after*.
   say @rest.join(' / ') ~ " !";
 }
 say as-many('Happy', 'Happy', 'Birthday'); #=> Happy / Birthday !
-                                           # Note that the splat did not consume the parameter before.
+                                           # Note that the splat did not consume
+                                           #  the parameter before.
 
-## You can call a function with an array using the "argument list flattening" operator `|`
-#  (it's not actually the only feature of the operator, but it's one of them)
+## You can call a function with an array using the
+# "argument list flattening" operator `|`
+# (it's not actually the only role of this operator, but it's one of them)
 sub concat3($a, $b, $c) {
   say "$a, $b, $c";
 }
@@ -105,7 +120,8 @@ concat3(|@array); #=> a, b, c
 
 ## It can also have optional arguments:
 sub with-optional($arg?) { # the "?" marks the argument optional
-  say "I might return `(Any)` if I don't have an argument passed, or I'll return my argument";
+  say "I might return `(Any)` if I don't have an argument passed,
+      or I'll return my argument";
   $arg;
 }
 with-optional; # returns Any
@@ -132,14 +148,15 @@ with-named(1, named => 6); #=> 7
 
 with-named(2, :named(5)); #=> 7
 with-named(3, :4named); #=> 7
-                        # (special colon pair syntax for numbers, mainly useful for `:2nd` etc)
+                        # (special colon pair syntax for numbers,
+                        # to be used with s// and such, see later)
 
 with-named(3); # warns, because we tried to use the undefined $named in a `+`:
                # by default, named arguments are *optional*
 
 # To make a named argument mandatory, you can use `?`'s inverse, `!`
 sub with-mandatory-named(:$str!)  {
-  say "$named !";
+  say "$str !";
 }
 with-mandatory-named(str => "My String"); #=> My String !
 with-mandatory-named; # run time error: "Required named parameter not passed" 
@@ -171,10 +188,11 @@ named-def(def => 15); #=> 15
 
 ### Containers
 # In Perl 6, values are actually stored in "containers".
-# The assignment operator asks the container on the left to store the value on its right.
-# When passed around, containers are marked as immutable. Which means that, in a function,
-#  you'll get an error if you try to mutate one of your arguments.
-# If you really need to, you can ask for a mutable container using `is rw` :
+# The assignment operator asks the container on the left to store the value on
+#  its right. When passed around, containers are marked as immutable.
+# Which means that, in a function, you'll get an error if you try to
+#  mutate one of your arguments.
+# If you really need to, you can ask for a mutable container using `is rw`:
 sub mutate($n is rw) {
   $n++;
   say "\$n is now $n !";
@@ -182,24 +200,26 @@ sub mutate($n is rw) {
 
 # If what you want is a copy instead, use `is copy`.
 
-# A sub itself returns a container, which means it can be marked as rw :
+# A sub itself returns a container, which means it can be marked as rw:
 my $x = 42;
 sub mod() is rw { $x }
-mod() = 52; # in this case, the parentheses are mandatory (else Perl 6 thinks it's a "term")
+mod() = 52; # in this case, the parentheses are mandatory
+            # (else Perl 6 thinks `mod` is a "term")
 say $x; #=> 52
 
 
 ### Control Flow Structures
 
 # You don't need to put parenthesis around the condition,
-# but that also means you always have to use brackets (`{ }`) for their body :
+# but that also means you always have to use brackets (`{ }`) for their body:
 
 ## Conditionals
 
 # - `if`
-# Before talking about `if`, we need to know which values are "Truthy" (represent True),
-#  and which are "Falsey" (or "Falsy") -- meaning they represent False.
-# Only these values are Falsey: (), 0, "0", Nil, A type, and of course False itself.
+# Before talking about `if`, we need to know which values are "Truthy"
+#  (represent True), and which are "Falsey" (or "Falsy") -- represent False.
+# Only these values are Falsey: (), 0, "0", Nil, A type (like `Str` or `Int`),
+#  and of course False itself.
 # Every other value is Truthy.
 if True {
   say "It's true !";
@@ -217,18 +237,18 @@ say "Quite truthy" if True;
 # - Ternary conditional, "?? !!" (like `x ? y : z` in some other languages)
 my $a = $condition ?? $value-if-true !! $value-if-false;
 
-# - `given`-`when` looks like other languages `switch`, but it's much more powerful thanks to smart matching,
-# and thanks to Perl 6's "topic variable", $_.
+# - `given`-`when` looks like other languages `switch`, but much more
+# powerful thanks to smart matching and thanks to Perl 6's "topic variable", $_.
 # This variable contains the default argument of a block,
 #  a loop's current iteration (unless explicitly named), etc.
-# Given simply puts its argument into `$_` (like a block would do),
-#  and `when` uses it using the "smart matching" operator.
-# Since other Perl 6 constructs use this variable (as said before, like `for`, blocks, etc),
-#  this means the powerful `when` is not only applicable along with a `given`,
-#  but instead anywhere a `$_` exists.
+# `given` simply puts its argument into `$_` (like a block would do),
+#  and `when` compares it using the "smart matching" (`~~`) operator.
+# Since other Perl 6 constructs use this variable (as said before, like `for`,
+# blocks, etc), this means the powerful `when` is not only applicable along with
+# a `given`, but instead anywhere a `$_` exists.
 given "foo bar" {
-  when /foo/ { # you'll read about the smart-matching operator below -- just know `when` uses it
-               # this is equivalent to `if $_ ~~ /foo/`
+  when /foo/ { # Don't worry about smart matching -- just know `when` uses it.
+               # This is equivalent to `if $_ ~~ /foo/`.
     say "Yay !";
   }
   when $_.chars > 50 { # smart matching anything with True (`$a ~~ True`) is True,
@@ -242,15 +262,17 @@ given "foo bar" {
 
 ## Looping constructs
 
-# - `loop` is an infinite loop if you don't pass it arguments, but can also be a c-style `for` :
+# - `loop` is an infinite loop if you don't pass it arguments,
+# but can also be a c-style `for`:
 loop {
   say "This is an infinite loop !";
   last; # last breaks out of the loop, like the `break` keyword in other languages
 }
 
 loop (my $i = 0; $i < 5; $i++) {
-  next if $i == 3; # `next` skips to the next iteration, like `continue` in other languages.
-                   # Notice that you can also use postfix conditionals, loops, etc.
+  next if $i == 3; # `next` skips to the next iteration, like `continue`
+                   # in other languages. Note that you can also use postfix
+                   # conditionals, loops, etc.
   say "This is a C-style for loop !";
 }
 
@@ -270,12 +292,13 @@ for @array {
 }
 
 for @array {
-  next if $_ == 3; # you can skip to the next iteration (like `continue` in C-like languages)
-  redo if $_ == 4; # you can re-do the iteration, keeping the same topic variable (`$_`)
-  last if $_ == 5; # you can also break out of a loop (like `break` in C-like languages)
+  # You can...
+  next if $_ == 3; # Skip to the next iteration (`continue` in C-like languages).
+  redo if $_ == 4; # Re-do the iteration, keeping the same topic variable (`$_`).
+  last if $_ == 5; # Or break out of a loop (like `break` in C-like languages).
 }
 
-# Note - the "lambda" `->` syntax isn't reserved to `for` :
+# Note - the "lambda" `->` syntax isn't reserved to `for`:
 if long-computation() -> $result {
   say "The result is $result";
 }
@@ -283,15 +306,15 @@ if long-computation() -> $result {
 ### Operators
 
 ## Since Perl languages are very much operator-based languages
-## Perl 6 operators are actually just funny-looking subroutines, in syntactic categories,
-##  like infix:<+> (addition) or prefix:<!> (bool not)
+## Perl 6 operators are actually just funny-looking subroutines, in syntactic
+##  categories, like infix:<+> (addition) or prefix:<!> (bool not).
 
-## The categories are :
-# - "prefix" : before (like `!` in `!True`).
-# - "postfix" : after (like `++` in `$a++`).
-# - "infix" : in between (like `*` in `4 * 3`).
-# - "circumfix" : around (like `[`-`]` in `[1, 2]`).
-# - "post-circumfix" : around, after another term (like `{`-`}` in `%hash{'key'}`)
+## The categories are:
+# - "prefix": before (like `!` in `!True`).
+# - "postfix": after (like `++` in `$a++`).
+# - "infix": in between (like `*` in `4 * 3`).
+# - "circumfix": around (like `[`-`]` in `[1, 2]`).
+# - "post-circumfix": around, after another term (like `{`-`}` in `%hash{'key'}`)
 
 ## The associativity and precedence list are explained below.
 
@@ -312,12 +335,15 @@ if long-computation() -> $result {
 (1, 2) eqv (1, 3);
 
 # - `~~` is smart matching
-# for a complete combinations list, use this table : http://perlcabal.org/syn/S03.html#Smart_matching
+# For a complete list of combinations, use this table:
+# http://perlcabal.org/syn/S03.html#Smart_matching
 'a' ~~ /a/; # true if matches regexp
 'key' ~~ %hash; # true if key exists in hash
-$arg ~~ &bool-returning-function; # true if the function, passed `$arg` as an argument, returns True
-1 ~~ Int; # "is of type"
-1 ~~ True; # smart-matching against a boolean always returns that boolean (and will warn).
+$arg ~~ &bool-returning-function; # `True` if the function, passed `$arg`
+                                  # as an argument, returns `True`.
+1 ~~ Int; # "has type" (check superclasses and roles)
+1 ~~ True; # smart-matching against a boolean always returns that boolean
+           # (and will warn).
 
 # - `===` is value identity and uses `.WHICH` on the objects to compare them
 # - `=:=` is container identity and uses `VAR()` on the objects to compare them
@@ -330,38 +356,44 @@ $arg ~~ &bool-returning-function; # true if the function, passed `$arg` as an ar
 3 .. 7; # 3 to 7, both included
 # `^` on either side them exclusive on that side :
 3 ^..^ 7; # 3 to 7, not included (basically `4 .. 6`)
-# this also works as a shortcut for `0..^N`
+# This also works as a shortcut for `0..^N`:
 ^10; # means 0..^10
 
-# This also allows us to demonstrate that Perl 6 has lazy arrays, using the Whatever Star :
+# This also allows us to demonstrate that Perl 6 has lazy arrays,
+#  using the Whatever Star:
 my @array = 1..*; # 1 to Infinite !
-say @array[^10]; # you can pass arrays as subscripts and it'll return an array of results
-                 # this will print "1 2 3 4 5 6 7 8 9 10" (and not run out of memory !)
-# Note : when reading an infinite list, Perl 6 will "reify" the elements it needs, then keep them in memory
-# They won't be calculated more than once.
+say @array[^10]; # you can pass arrays as subscripts and it'll return
+                 #  an array of results. This will print
+                 # "1 2 3 4 5 6 7 8 9 10" (and not run out of memory !)
+# Note : when reading an infinite list, Perl 6 will "reify" the elements
+# it needs, then keep them in memory. They won't be calculated more than once.
                  
-# Warning, though: if you try this example in the REPL and juste put `1..*`,
-# Perl 6 will be forced to try and evaluate the whole array (to print it),
-# so you'll end with an infinite loop.
+# Warning, though: if you try this example in the REPL and just put `1..*`,
+#  Perl 6 will be forced to try and evaluate the whole array (to print it),
+#  so you'll end with an infinite loop.
 
 ## * And, Or
 3 && 4; # 4, which is Truthy. Calls `.Bool` on `4` and gets `True`.
 0 || False; # False. Calls `.Bool` on `0`
 
 ## * Short-circuit (and tight) versions of the above
-$a && $b && $c; # returns the first argument that evaluates to False, or the last argument
+$a && $b && $c; # Returns the first argument that evaluates to False,
+                # or the last argument.
 $a || $b;
 
-# And because you're going to want them, you also have composed assignment operators:
+# And because you're going to want them,
+#  you also have composed assignment operators:
 $a *= 2; # multiply and assignment
 $b %%= 5; # divisible by and assignment
-$c .= say; # method call and assignment
+@array .= sort; # calls the `sort` method and assigns the result back
 
 ### More on subs !
-# As we said before, Perl 6 has *really* powerful subs.
-# We're going to see a few more key concepts that make them better than in any other language :-).
+# As we said before, Perl 6 has *really* powerful subs. We're going to see
+# a few more key concepts that make them better than in any other language :-).
 
-## Unpacking ! It's the ability to "extract" arrays and keys. It'll work in `my`s and parameters.
+## Unpacking !
+# It's the ability to "extract" arrays and keys.
+# It'll work in `my`s and in parameter lists.
 my ($a, $b) = 1, 2;
 say $a; #=> 1
 my ($, $, $c) = 1, 2, 3; # keep the non-interesting anonymous
@@ -377,14 +409,17 @@ sub foo(@array [$fst, $snd]) {
 foo(@tail); #=> My first is 2, my second is 3 ! All in all, I'm 2 3
 
 
-# If you're not using the array itself, you can also keep it anonymous, much like a scalar:
+# If you're not using the array itself, you can also keep it anonymous,
+#  much like a scalar:
 sub first-of-array(@ [$fst]) { $fst }
 first-of-array(@small); #=> 1
-first-of-array(@tail); # errors with "Too many positional parameters passed" (the array is too big)
+first-of-array(@tail); # Throws an error "Too many positional parameters passed"
+                       # (which means the array is too big).
 
 # You can also use a slurp ...
-sub slurp-in-array(@ [$fst, *@rest]) { # you could decide to keep `*@rest` anonymous
-  say $fst + @rest.elems;
+sub slurp-in-array(@ [$fst, *@rest]) { # You could keep `*@rest` anonymous
+  say $fst + @rest.elems; # `.elems` returns a list's length.
+                          # Here, `@rest` is `(3,)`, since `$fst` holds the `2`.
 }
 slurp-in-array(@tail); #=> 3
 
@@ -403,18 +438,21 @@ sub key-of(% (:value($val), :qua($qua))) {
 }
 
 # Then call it with a hash: (you need to keep the brackets for it to be a hash)
-key-of({value => 1});
+key-of({value => 'foo', qua => 1});
 #key-of(%hash); # the same (for an equivalent `%hash`)
 
-## The last expression of a sub is returned automatically (though you may use the `return` keyword, of course):
+## The last expression of a sub is returned automatically
+# (though you may use the `return` keyword, of course):
 sub next-index($n) {
   $n + 1;
 }
 my $new-n = next-index(3); # $new-n is now 4
 
-# This is true for everything, except for the looping constructs (due to performance reasons):
-#  there's no purpose in building a list if we're just going to discard all the results.
-# If you still want to build one, you can use the `do` prefix: (or the `gather` prefix, which we'll see later)
+# This is true for everything, except for the looping constructs
+# (due to performance reasons): there's reason to build a list
+#  if we're just going to discard all the results.
+# If you still want to build one, you can use the `do` statement prefix:
+#  (or the `gather` prefix, which we'll see later)
 sub list-of($n) {
   do for ^$n { # note the use of the range-to prefix operator `^` (`0..^N`)
     $_ # current loop iteration
@@ -424,15 +462,16 @@ my @list3 = list-of(3); #=> (0, 1, 2)
 
 ## You can create a lambda with `-> {}` ("pointy block") or `{}` ("block")
 my &lambda = -> $argument { "The argument passed to this lambda is $argument" }
-# `-> {}` and `{}` are pretty much the same thing, except that the former can take arguments,
-#  and that the latter can be mistaken as a hash by the parser.
+# `-> {}` and `{}` are pretty much the same thing, except that the former can
+# take arguments, and that the latter can be mistaken as a hash by the parser.
 
 # We can, for example, add 3 to each value of an array using map:
 my @arrayplus3 = map({ $_ + 3 }, @array); # $_ is the implicit argument
 
-# a sub (`sub {}`) has different semantics than a block (`{}` or `-> {}`):
-# a block doesn't have a "function context" (though it can have arguments), which means that if you
-#  return from it, you're going to return from the parent function, compare:
+# A sub (`sub {}`) has different semantics than a block (`{}` or `-> {}`):
+# A block doesn't have a "function context" (though it can have arguments),
+#  which means that if you return from it,
+#  you're going to return from the parent function. Compare:
 sub is-in(@array, $elem) {
   # this will `return` out of the `is-in` sub
   # once the condition evaluated to True, the loop won't be run anymore
@@ -441,28 +480,32 @@ sub is-in(@array, $elem) {
 sub truthy-array(@array) {
   # this will produce an array of `True` and `False`:
   # (you can also say `anon sub` for "anonymous subroutine")
-  map(sub { if $_ { return True } else { return False } }, @array);
+  map(sub ($i) { if $i { return True } else { return False } }, @array);
   # ^ the `return` only returns from the anonymous `sub`
 }
 
 # You can also use the "whatever star" to create an anonymous function
 # (it'll stop at the furthest operator in the current expression)
 my @arrayplus3 = map(*+3, @array); # `*+3` is the same as `{ $_ + 3 }`
-my @arrayplus3 = map(*+*+3, @array); # also works. Same as `-> $a, $b { $a + $b + 3 }`
+my @arrayplus3 = map(*+*+3, @array); # Same as `-> $a, $b { $a + $b + 3 }`
+                                     # also `sub ($a, $b) { $a + $b + 3 }`
 say (*/2)(4); #=> 2
               # Immediatly execute the function Whatever created.
 say ((*+3)/5)(5); #=> 1.6
                   # works even in parens !
 
-# but if you need to have more than one argument (`$_`) in a block (without wanting to resort to `-> {}`),
+# But if you need to have more than one argument (`$_`)
+#  in a block (without wanting to resort to `-> {}`),
 #  you can also use the implicit argument syntax, `$^` :
-map({ $^a + $^b + 3 }, @array); # same as the above
+map({ $^a + $^b + 3 }, @array); # equivalent to following:
+map(sub ($a, $b) { $a + $b + 3 }, @array); # (here with `sub`)
 
-# Note : those are sorted lexicographically. `{ $^b / $^a }` is like `-> $a, $b { $b / $a }`
+# Note : those are sorted lexicographically.
+# `{ $^b / $^a }` is like `-> $a, $b { $b / $a }`
 
 ## Multiple Dispatch
-# Perl 6 can decide which variant of a `sub` to call based on the type of the arguments,
-# or on arbitrary preconditions, like with a type or a `where`:
+# Perl 6 can decide which variant of a `sub` to call based on the type of the
+# arguments, or on arbitrary preconditions, like with a type or a `where`:
 
 # with types
 multi sub sayit(Int $n) { # note the `multi` keyword here
@@ -472,21 +515,25 @@ multi sayit(Str $s) } # the `sub` is the default
   say "String: $s";
 }
 sayit("foo"); # prints "String: foo"
-sayit(True); # fails at *compile time* with "calling 'sayit' will never work with arguments of types ..."
+sayit(True); # fails at *compile time* with
+             # "calling 'sayit' will never work with arguments of types ..."
 
 # with arbitrary precondition:
 multi is-big(Int $n where * > 50) { "Yes !" } # using a closure
-multi is-big(Int $ where 10..50) { "Quite." } # this uses smart-matching (could use a regexp, etc)
+multi is-big(Int $ where 10..50) { "Quite." } # Using smart-matching
+                                              # (could use a regexp, etc)
 multi is-big(Int $) { "No" }
 
-# you can also name these checks, by creating "subsets":
+# You can also name these checks, by creating "subsets":
 subset Even of Int where * %% 2;
 
-multi odd-or-even(Even) { "Even" } # the main case using the type. We don't name the argument
+multi odd-or-even(Even) { "Even" } # The main case using the type.
+                                   # We don't name the argument.
 multi odd-or-even($) { "Odd" } # "else"
 
 # You can even dispatch based on a positional's argument presence !
-multi with-or-without-you(:$with!) { # make it mandatory to be able to dispatch against it
+multi with-or-without-you(:$with!) { # You need make it mandatory to
+                                     # be able to dispatch against it.
   say "I can live ! Actually, I can't.";
 }
 multi with-or-without-you {
@@ -494,17 +541,21 @@ multi with-or-without-you {
 }
 # This is very, very useful for many purposes, like `MAIN` subs (covered later),
 #  and even the language itself is using it in several places.
-# `is`, for example, is actually a `multi sub` named `trait_mod:<is>`, and it works off that.
-# `is rw`, for example, is a dispatch to a function with this signature:
+#
+# - `is`, for example, is actually a `multi sub` named `trait_mod:<is>`,
+#  and it works off that.
+# - `is rw`, is simply a dispatch to a function with this signature:
 # sub trait_mod:<is>(Routine $r, :$rw!) {}
-# (commented because running this would probably lead to some very surprising side-effects !)
+#
+# (commented because running this would be a terrible idea !)
 
 
 ### Scoping
-# In Perl 6, contrarily to many scripting languages (Python, Ruby, PHP, for example),
-#  you are to declare your variables before using them. You already saw it, with `my`.
-# (there are other declarator keywords, like `our`, `has` and `state`, but we'll talk about them later)
-# This is called "lexical scoping", where in inner blocks, you can access variables from outer blocks.
+# In Perl 6, contrarily to many scripting languages (like Python, Ruby, PHP),
+#  you are to declare your variables before using them. You know `my`.
+# (there are other declarators, `our`, `state`, ..., which we'll see later).
+# This is called "lexical scoping", where in inner blocks,
+#  you can access variables from outer blocks.
 my $foo = 'Foo';
 sub foo {
   my $bar = 'Bar';
@@ -516,36 +567,40 @@ sub foo {
 foo()(); #=> 'Foo Bar'
 
 # As you can see, `$foo` and `$bar` were captured.
-# But if we were to try and use `$bar` outside of `foo`, the variable would be undefined.
-#  (and you'd get a compile time error)
+# But if we were to try and use `$bar` outside of `foo`,
+# the variable would be undefined (and you'd get a compile time error).
 
 # Perl 6 has another kind of scope : dynamic scope.
 # They use the twigil (composed sigil) `*` to mark dynamically-scoped variables:
 my $*a = 1;
-# Dyamically-scoped variables depend on the current call stack, instead of the current block stack.
+# Dyamically-scoped variables depend on the current call stack,
+#  instead of the current block depth.
 sub foo {
   my $*foo = 1;
   bar(); # call `bar` in-place
 }
 sub bar {
-  say $*foo; # Perl 6 will look into the call stack instead, and find `foo`'s `$*a`,
-             # even though the blocks aren't nested (they're call-nested).
+  say $*foo; # `$*a` will be looked in the call stack, and find `foo`'s,
+             #  even though the blocks aren't nested (they're call-nested).
              #=> 1
 }
 
 ### Object Model
 
 ## Perl 6 has a quite comprehensive object model
-## You declare a class with the keyword `class`, fields with `has`, methods with `method`.
-## In Perl 6, every field is private, and named `$!attr`, but if you declare it with `$.`,
-##  you get a public (immutable) accessor along with it.
+# You declare a class with the keyword `class`, fields with `has`,
+# methods with `method`. Every field to private, and is named `$!attr`,
+# but you have `$.` to get a public (immutable) accessor along with it.
+# (using `$.` is like using `$!` plus a `method` with the same name)
 
-# (Perl 6's object model ("SixModel") is very flexible, and allows you to dynamically add methods,
-#  change semantics, etc -- This will not be covered here, and you should refer to the Synopsis)
+# (Perl 6's object model ("SixModel") is very flexible,
+# and allows you to dynamically add methods, change semantics, etc ...
+# (this will not be covered here, and you should refer to the Synopsis).
 
 class A {
-  has $.field; # `$.field` is immutable. Use `$!field` from inside the class to modify it.
-  has $.other-field is rw; # You can, however, mark a public field as being read/write.
+  has $.field; # `$.field` is immutable.
+               # From inside the class, use `$!field` to modify it.
+  has $.other-field is rw; # You can obviously mark a public field `rw`.
   has Int $!private-field = 10;
 
   method get-value {
@@ -556,7 +611,7 @@ class A {
     # $.field = $n; # As stated before, you can't use the `$.` immutable version.
     $!field = $n;   # This works, because `$!` is always mutable.
     
-    $.other-field = 5; # This works, because `$.other-field` was declared `rw` (mutable).
+    $.other-field = 5; # This works, because `$.other-field` is `rw`.
   }
   
   method !private-method {
@@ -565,13 +620,15 @@ class A {
 };
 
 # Create a new instance of A with $.field set to 5 :
-# note : you can't set private-field from here (more later on)
+# Note: you can't set private-field from here (more later on).
 my $a = A.new(field => 5);
 $a.get-value; #=> 18
 #$a.field = 5; # This fails, because the `has $.field` is immutable
-$a.other-field = 10; # This, however, works, because the public field is mutable (`rw`).
+$a.other-field = 10; # This, however, works, because the public field
+                     #  is mutable (`rw`).
 
-## Perl 6 also has inheritance (along with multiple inheritance ... Considered a misfeature by many)
+## Perl 6 also has inheritance (along with multiple inheritance)
+# (though considered a misfeature by many)
 
 class A {
   has $.val;
@@ -591,12 +648,14 @@ class B is A { # inheritance uses `is`
   method bar { $.val * 10 } # this shadows A's `bar`
 }
 
-my B $b .= new(val => 5); # When you use `my T $var`, `$var` starts off with `T` itself in it,
-                # so you can call `new` on it.
-                # (`.=` is just the compound operator composed of the dot-call and of the assignment operator
-                #  `$a .= b` is the same as `$a = $a.b`)
-                # Also note that `BUILD` (the method called inside `new`)  will set parent properties too,
-                # so you can pass `val => 5` 
+# When you use `my T $var`, `$var` starts off with `T` itself in it,
+# so you can call `new` on it.
+# (`.=` is just the dot-call and the assignment operator:
+#  `$a .= b` is the same as `$a = $a.b`)
+# Also note that `BUILD` (the method called inside `new`)
+#  will set parent properties too, so you can pass `val => 5`.
+my B $b .= new(val => 5);
+
 # $b.not-inherited; # This won't work, for reasons explained above
 $b.foo; # prints 5
 $b.bar; #=> 50, since it calls B's `bar`
@@ -613,27 +672,30 @@ role PrintableVal {
 class Item does PrintableVal {
   has $.val;
   
-  # When `does`-ed, a `role` literally "mixes in" the class :
-  # the methods and fields are put together, which means a class can access
-  # the private fields/methods of its roles (but not the inverse !) :
+  # When `does`-ed, a `role` literally "mixes in" the class:
+  #  the methods and fields are put together, which means a class can access
+  #  the private fields/methods of its roles (but not the inverse !):
   method access {
     say $!counter++;
   }
   
-  # However, this :
+  # However, this:
   # method print {}
-  # is an error, since the compiler wouldn't know which `print` to use :
-  # contrarily to inheritance, methods mixed in can't be shadowed - they're put at the same "level"
+  # is ONLY valid when `print` isn't a `multi` with the same dispatch.
+  # (this means a parent class can shadow a child class's `multi print() {}`,
+  #  but it's an error if a role does)
   
-  # NOTE: You can use a role as a class (with `is ROLE`). In this case, methods will be shadowed,
-  # since the compiler will consider `ROLE` to be a class
+  # NOTE: You can use a role as a class (with `is ROLE`). In this case, methods
+  # will be shadowed, since the compiler will consider `ROLE` to be a class.
 }
 
 ### Exceptions
-# Exceptions are built on top of classes, usually in the package `X` (like `X::IO`).
-# Unlike many other languages, in Perl 6, you put the `CATCH` block *within* the block to `try`.
-# By default, a `try` has a `CATCH` block that catches any exception (`CATCH { default {} }`).
-# You can redefine it using `when`s (and `default`) to handle the exceptions you want:
+# Exceptions are built on top of classes, in the package `X` (like `X::IO`).
+# Unlike many other languages, in Perl 6, you put the `CATCH` block *within* the
+#  block to `try`. By default, a `try` has a `CATCH` block that catches
+#  any exception (`CATCH { default {} }`).
+# You can redefine it using `when`s (and `default`)
+#  to handle the exceptions you want:
 try {
   open 'foo';
   CATCH {
@@ -649,20 +711,20 @@ die X::AdHoc.new(payload => 'Error !');
 # TODO CONTROL
 
 ### Packages
-# Packages are a way to reuse code. Packages are like "namespaces", and any element of the six model
-#  (`module`, `role`, `class`, `grammar`, `subset` and `enum`) are actually packages.
-#  (you can say that packages are the lowest common denomitor between them)
-# Packages play a big part in a language, as Perl is well-known for CPAN,
+# Packages are a way to reuse code. Packages are like "namespaces", and any
+#  element of the six model (`module`, `role`, `class`, `grammar`, `subset`
+#  and `enum`) are actually packages. (Packages are the lowest common denomitor)
+# Packages are important - especially as Perl is well-known for CPAN,
 #  the Comprehensive Perl Archive Network.
-# You usually don't use packages directly : you use `class Package::Name::Here;`, or if you
-#  only want to export variables/subs, you can use `module`:
-module Hello::World { # bracketed form
-                      # if `Hello` doesn't exist yet, it'll just be created as an "empty package stub"
-                      # that can be redeclared as something else later.
-  # declarations here
+# You usually don't use packages directly: you use `class Package::Name::Here;`,
+# or if you only want to export variables/subs, you can use `module`:
+module Hello::World { # Bracketed form
+                      # If `Hello` doesn't exist yet, it'll just be a "stub",
+                      #  that can be redeclared as something else later.
+  # ... declarations here ...
 }
 module Parse::Text; # file-scoped form
-grammar Parse::Text::Grammar { # A grammar is a fine package, which you could `use`
+grammar Parse::Text::Grammar { # A grammar is a package, which you could `use`
 }
 
 # NOTE for Perl 5 users: even though the `package` keyword exists,
@@ -692,7 +754,8 @@ my $actions = JSON::Tiny::Actions.new;
 module Foo::Bar {
   our $n = 1; # note: you can't put a type constraint on an `our` variable
   our sub inc {
-    our sub available { # if you try to make scoped `sub`s `our` ... Better know what you're doing (Don't !).
+    our sub available { # If you try to make inner `sub`s `our`...
+                        # Better know what you're doing (Don't !).
       say "Don't do that. Seriously. You'd get burned.";
     }
     my sub unavailable { # `my sub` is the default
@@ -725,23 +788,24 @@ sub fixed-rand {
 fixed-rand for ^10; # will print the same number 10 times
 
 # Note, however, that they exist separately in different enclosing contexts.
-# If you declare a function with a `state` within a loop, it'll re-create the variable
-# for each iteration of loop. See:
+# If you declare a function with a `state` within a loop, it'll re-create the
+#  variable for each iteration of the loop. See:
 for ^5 -> $a {
   sub foo {
     state $val = rand; # This will be a different value for every value of `$a`
   }
   for ^5 -> $b {
-    say foo; # This will print the same value 5 times, but only 5. Next iteration will re-run `rand`
+    say foo; # This will print the same value 5 times, but only 5.
+             # Next iteration will re-run `rand`.
   }
 }
 
 
 
 ### Phasers
-# Phasers in Perl 6 are blocks that happen at determined points of time in your program
-# When the program is compiled, when a for loop runs, when you leave a block, when
-#  an exception gets thrown ... (`CATCH` is actually a phaser !)
+# Phasers in Perl 6 are blocks that happen at determined points of time in your
+#  program. When the program is compiled, when a for loop runs, when you leave a
+#  block, when an exception gets thrown ... (`CATCH` is actually a phaser !)
 # Some of them can be used for their return values, some of them can't
 #  (those that can have a "[*]" in the beginning of their explanation text).
 # Let's have a look !
@@ -782,7 +846,7 @@ say "This code took " ~ (time - CHECK time) ~ "s to run";
 
 # ... or clever organization:
 sub do-db-stuff {
-  ENTER $db.start-transaction; # create a new transaction everytime we enter the sub
+  ENTER $db.start-transaction; # New transaction everytime we enter the sub
   KEEP $db.commit; # commit the transaction if all went well
   UNDO $db.rollback; # or rollback if all hell broke loose
 }
@@ -791,7 +855,7 @@ sub do-db-stuff {
 # Those act a bit like phasers: they affect the behavior of the following code.
 # Though, they run in-line with the executable code, so they're in lowercase.
 # (`try` and `start` are theoretically in that list, but explained somewhere else)
-# Note: all of these (except start) don't need explicit brackets (`{` and `}`) for their block.
+# Note: all of these (except start) don't need explicit brackets `{` and `}`.
 
 # - `do` (that you already saw) - runs a block or a statement as a term
 # You can't normally use a statement as a value (or "term"):
@@ -848,8 +912,9 @@ say nilthingie.perl; #=> Nil
 
 ## Everybody loves operators ! Let's get more of them
 
-## The precedence list can be found here : http://perlcabal.org/syn/S03.html#Operator_precedence
-## But first, we need a little explanation about associativity :
+# The precedence list can be found here:
+# http://perlcabal.org/syn/S03.html#Operator_precedence
+# But first, we need a little explanation about associativity:
 
 # * Binary operators:
 $a ! $b ! $c; # with a left-associative `!`, this is `($a ! $b) ! $c`
@@ -864,8 +929,9 @@ $a ! $b ! $c; # with a list-associative `!`, this is `infix:<>`
 !$a! # with non-associative `!`, this is illegal
 
 ## Create your own operators !
-# Okay, you've been reading all of that, so I guess I should try to show you something exciting.
-# I'll tell you a little secret (actually not):
+# Okay, you've been reading all of that, so I guess I should try
+#  to show you something exciting.
+# I'll tell you a little secret (or not-so-secret):
 # In Perl 6, all operators are actually just funny-looking subroutines.
 
 # You can declare an operator just like you declare a sub:
@@ -890,7 +956,7 @@ say 5!; #=> 120
 sub infix:<times>(Int $n, Block $r) { # infix in the middle
   for ^$n {
     $r(); # You need the explicit parentheses to call the function in `$r`,
-          #  else you'd be referring at the variable itself, kind of like with `&r`.
+          #  else you'd be referring at the variable itself, like with `&r`.
   }
 }
 3 times -> { say "hello" }; #=> hello
@@ -906,36 +972,47 @@ sub circumfix:<[ ]>(Int $n) {
 say [5]; #=> 3125
          # circumfix is around. Again, not whitespace.
 
-sub postcircumfix:<{ }>(Str $s, Int $idx) { # post-circumfix is "after a term, around something"
+sub postcircumfix:<{ }>(Str $s, Int $idx) {
+  # post-circumfix is
+  # "after a term, around something"
   $s.substr($idx, 1);
 }
 say "abc"{1}; #=> b
               # after the term `"abc"`, and around the index (1)
 
 # This really means a lot -- because everything in Perl 6 uses this.
-# For example, to delete a key from a hash, you use the `:delete` adverb (named argument)
+# For example, to delete a key from a hash, you use the `:delete` adverb
+#  (a simple named argument underneath):
 %h{$key}:delete;
 # equivalent to:
-postcircumfix:<{ }>(%h, $key, :delete);
-# It's *all* using the same building blocks! Syntactic categories (prefix infix ...),
-#  named arguments (adverbs), ..., used to build the language are available to you.
+postcircumfix:<{ }>(%h, $key, :delete); # (you can call operators like that)
+# It's *all* using the same building blocks!
+# Syntactic categories (prefix infix ...), named arguments (adverbs), ...,
+#  - used to build the language - are available to you.
 
-# (you are, obviously, recommended against making an operator out of *everything* --
-#  with great power comes great responsibility)
+# (you are, obviously, recommended against making an operator out of
+# *everything* -- with great power comes great responsibility)
 
 ## Meta operators !
-# Oh boy, get ready. Get ready, because we're dwelving deep into the rabbit's hole,
-#  and you probably won't want to go back to other languages after reading that.
+# Oh boy, get ready. Get ready, because we're dwelving deep
+#  into the rabbit's hole, and you probably won't want to go
+#  back to other languages after reading that.
 #  (I'm guessing you don't want to already at that point).
 # Meta-operators, as their name suggests, are *composed* operators.
 # Basically, they're operators that apply another operator.
 
 ## * Reduce meta-operator
-# It's a prefix meta-operator that takes a binary functions and one or many lists.
-# If it doesn't get passed any argument, it either return a "default value" for this operator
-#  (a value that'd be non-meaningful if contained in a list) or `Any` if there's none.
-# Otherwise, it pops an element from the list(s) one at a time, and applies the binary function
-#  to the last result (or the list's first element) and the popped element.
+# It's a prefix meta-operator that takes a binary functions and
+#  one or many lists. If it doesn't get passed any argument,
+#  it either return a "default value" for this operator
+#  (a value that wouldn't change the result if passed as one
+#   of the element of the list to be passed to the operator),
+#  or `Any` if there's none (examples below).
+#
+# Otherwise, it pops an element from the list(s) one at a time, and applies
+#  the binary function to the last result (or the list's first element)
+#  and the popped element.
+#
 # To sum a list, you could use the reduce meta-operator with `+`, i.e.:
 say [+] 1, 2, 3; #=> 6
 # equivalent to `(1+2)+3`
@@ -943,18 +1020,20 @@ say [*] 1..5; #=> 120
 # equivalent to `((((1*2)*3)*4)*5)`.
 
 # You can reduce with any operator, not just with mathematical ones.
-# For example, you could reduce with `//` to get the first defined element of a list:
+# For example, you could reduce with `//` to get
+#  the first defined element of a list:
 say [//] Nil, Any, False, 1, 5; #=> False
                                 # (Falsey, but still defined)
 
 
 # Default value examples:
-say [*] (); #=> 1
-say [+] (); #=> 0
-            # In both cases, they're results that, if they were contained in the lists,
-            # wouldn't have any impact on the final value (since N*1=N and N+0=N).
+say [*] (); #=> 1 
+say [+] (); #=> 0 
+            # In both cases, they're results that, were they in the lists,
+            #  wouldn't have any impact on the final value
+            #  (since N*1=N and N+0=N).
 say [//];   #=> (Any)
-            # There's no "default value" for `//`
+            # There's no "default value" for `//`.
 
 # You can also call it with a function you made up, using double brackets:
 sub add($a, $b) { $a + $b }
@@ -980,23 +1059,36 @@ say [[&add]] 1, 2, 3; #=> 6
 
 ## * Sequence operator
 # The sequence operator is one of Perl 6's most powerful features:
-# it's composed of first, on the left, the list you want Perl 6 to deduce from (and might include a closure),
-# and on the right, a value or the predicate for when to stop, or even Whatever for a lazy infinite list.
+# it's composed of first, on the left, the list you want Perl 6 to deduce from
+#  (and might include a closure), and on the right, a value or the predicate
+#  that says when to stop (or Whatever for a lazy infinite list).
 my @list = 1, 2, 3 ... 10; # basic deducing
-#my @list = 1, 3, 6 ... 10; # this throws you into an infinite loop, because Perl 6 can't figure out the end
-my @list = 1, 2, 3 ...^ 10; # as with ranges, you can exclude the last element (when the predicate matches)
-my @list = 1, 3, 9 ... * > 30; # you can use a predicate (with the Whatever Star, here)
+#my @list = 1, 3, 6 ... 10; # this throws you into an infinite loop,
+                            #  because Perl 6 can't figure out the end
+my @list = 1, 2, 3 ...^ 10; # as with ranges, you can exclude the last element
+                            # (the iteration when the predicate matches).
+my @list = 1, 3, 9 ... * > 30; # you can use a predicate
+                               # (with the Whatever Star, here).
 my @list = 1, 3, 9 ... { $_ > 30 }; # (equivalent to the above)
-my @fib = 1, 1, *+* ... *; # lazy infinite list of prime numbers, computed using a closure !
+
+my @fib = 1, 1, *+* ... *; # lazy infinite list of prime numbers,
+                           #  computed using a closure!
 my @fib = 1, 1, -> $a, $b { $a + $b } ... *; # (equivalent to the above)
+my @fib = 1, 1, { $^a + $^b } ... *; #(... also equivalent to the above)
+# $a and $b will always take the previous values, meaning here
+#  they'll start with $a = 1 and $b = 1 (values we set by hand).
+#  then $a = 1 and $b = 2 (result from previous $a+$b), and so on.
+
 say @fib[^10]; #=> 1 1 2 3 5 8 13 21 34 55
                # (using a range as the index)
 # Note : as for ranges, once reified, elements aren't re-calculated.
-# That's why `@primes[^100]` will take a long time the first time you print it, then be instant
+# That's why `@primes[^100]` will take a long time the first time you print
+#  it, then be instant.
 
 
 ## * Sort comparison
-# They return one value of the `Order` enum : `Less`, `Same` and `More` (which numerify to -1, 0 or +1).
+# They return one value of the `Order` enum : `Less`, `Same` and `More`
+#  (which numerify to -1, 0 or +1).
 1 <=> 4; # sort comparison for numerics
 'a' leg 'b'; # sort comparison for string
 $obj eqv $obj2; # sort comparison using eqv semantics
@@ -1014,14 +1106,17 @@ say Any // Nil // 0 // 5; #=> 5
 say True ^^ False; #=> True
 
 ## * Flip Flop
-# The flip flop operators (`ff` and `fff`, equivalent to Perl 5/Ruby's `..` and `...`).
+# The flip flop operators (`ff` and `fff`, equivalent to P5's `..`/`...`).
 #  are operators that take two predicates to test:
-# They are `False` until their left side returns `True`, then are `True` until their right side returns `True`.
-# Like for ranges, you can exclude the iteration when it became `True`/`False` by using `^` on either side.
+# They are `False` until their left side returns `True`, then are `True` until
+#  their right side returns `True`.
+# Like for ranges, you can exclude the iteration when it became `True`/`False`
+#  by using `^` on either side.
 # Let's start with an example :
 for <well met young hero we shall meet later> {
   # by default, `ff`/`fff` smart-match (`~~`) against `$_`:
-  if 'met' ^ff 'meet' { # won't enter the if for "met" (explained in details below).
+  if 'met' ^ff 'meet' { # Won't enter the if for "met"
+                        #  (explained in details below).
     .say
   }
   
@@ -1031,35 +1126,42 @@ for <well met young hero we shall meet later> {
 }
 # This will print "young hero we shall meet" (excluding "met"):
 #  the flip-flop will start returning `True` when it first encounters "met"
-#  (but will still return `False` for "met" itself, due to the leading `^` on `ff`),
-#  until it sees "meet", which is when it'll start returning `False`.
+#  (but will still return `False` for "met" itself, due to the leading `^`
+#   on `ff`), until it sees "meet", which is when it'll start returning `False`.
 
 # The difference between `ff` (awk-style) and `fff` (sed-style) is that
-#  `ff` will test its right side just as its left side changes to `True`,
-#  and can get back to `False` right away (*except* it'll be `True` for the iteration that matched)
-#  while `fff` will wait for the next iteration to try its right side, once its left side changed:
+#  `ff` will test its right side right when its left side changes to `True`,
+#  and can get back to `False` right away
+#  (*except* it'll be `True` for the iteration that matched) -
+# While `fff` will wait for the next iteration to
+#  try its right side, once its left side changed:
 .say if 'B' ff 'B' for <A B C B A>; #=> B B
-                                    # because the right-hand-side was tested directly (and returned `True`).
-                                    # "B"s are still printed since it matched that time
-                                    #  (it just went back to `False` right away)
+                                    # because the right-hand-side was tested
+                                    # directly (and returned `True`).
+                                    # "B"s are printed since it matched that time
+                                    #  (it just went back to `False` right away).
 .say if 'B' fff 'B' for <A B C B A>; #=> B C B
-                                    # because the right-hand-side wasn't tested until `$_` became "C"
-                                    # (and thus did not match directly).
+                                    # The right-hand-side wasn't tested until
+                                    #  `$_` became "C"
+                                    # (and thus did not match instantly).
 
 # A flip-flop can change state as many times as needed:
-for <test start print this stop you stopped printing start printing again stop not anymore> {
+for <test start print it stop not printing start print again stop not anymore> {
   .say if $_ eq 'start' ^ff^ $_ eq 'stop'; # exclude both "start" and "stop",
                                            #=> "print this printing again"
 }
 
 # you might also use a Whatever Star,
 # which is equivalent to `True` for the left side or `False` for the right:
-for (1, 3, 60, 3, 40, 60) { # Note: the parenthesis are superfluous here -- sometimes called "superstitious"
- .say if $_ > 50 ff *; # Once the flip-flop reaches a number greater than 50, it'll never go back to `False`
+for (1, 3, 60, 3, 40, 60) { # Note: the parenthesis are superfluous here
+                            # (sometimes called "superstitious parentheses")
+ .say if $_ > 50 ff *; # Once the flip-flop reaches a number greater than 50,
+                       #  it'll never go back to `False`
                        #=> 60 3 40 60
 }
 
-# You can also use this property to create an `If` that'll not execute the first time :
+# You can also use this property to create an `If`
+#  that'll not go through the first time :
 for <a b c> {
   .say if * ^ff *; # the flip-flop is `True` and never goes back to `False`,
                    #  but the `^` makes it *not run* on the first iteration
@@ -1072,37 +1174,42 @@ for <a b c> {
 # Well, now that you know a good deal of Perl 6 already, we can get started.
 # First off, you'll have to forget about "PCRE regexps" (perl-compatible regexps).
 #
-# IMPORTANT: You may feel like you already know these because you know PCRE. You'd be wrong.
-# Some things are the same (like `?`, `+`, and `*`), but sometimes the semantics change (`|`).
+# IMPORTANT: Don't skip them because you know PCRE. They're different.
+# Some things are the same (like `?`, `+`, and `*`),
+#  but sometimes the semantics change (`|`).
 # Make sure you read carefully, because you might trip over a new behavior.
 #
-# Perl 6 has a looot of features related to RegExps. After all, Rakudo parses itself.
-# We're first going to look at the syntax itself, then talk about grammars (PEG-like),
-#  differences between the `token`, `regex` and `rule` keywords, and some more.
+# Perl 6 has many features related to RegExps. After all, Rakudo parses itself.
+# We're first going to look at the syntax itself,
+#  then talk about grammars (PEG-like), differences between
+#  `token`, `regex` and `rule` declarators, and some more.
 # Side note: you still have access to PCRE regexps using the `:P5` modifier.
 #  (we won't be discussing this in this tutorial, however)
 #
 # In essence, Perl 6 natively implements PEG ("Parsing Expression Grammars").
-# The pecking order for ambiguous parses is determined by a multi-level tie-breaking test:
+# The pecking order for ambiguous parses is determined by a multi-level
+#  tie-breaking test:
 #  - Longest token matching. `foo\s+` beats `foo` (by 2 or more positions)
 #  - Longest literal prefix. `food\w*` beats `foo\w*` (by 1)
-#  - Declaration from most-derived to less derived grammars (grammars are actually classes)
+#  - Declaration from most-derived to less derived grammars
+#     (grammars are actually classes)
 #  - Earliest declaration wins
 say so 'a' ~~ /a/; #=> True
 say so 'a' ~~ / a /; # More readable with some spaces!
 
-# In all our examples, we're going to use the smart-matching operator against a regexp.
-# We're converting the result using `so`, but in fact, it's returning a `Match` object.
-# They know how to respond to list indexing, hash indexing (and return the matched string).
-# The results of the match are also available as `$/` (implicitly lexically-scoped).
-# You can also use the capture variables (`$0`, `$1`, ... - starting at 0, not 1 !).
+# In all our examples, we're going to use the smart-matching operator against
+#  a regexp. We're converting the result using `so`, but in fact, it's
+#  returning a `Match` object. They know how to respond to list indexing,
+#  hash indexing, and return the matched string.
+# The results of the match are available as `$/` (implicitly lexically-scoped).
+# You can also use the capture variables (`$0`, `$1`, ... starting at 0, not 1 !).
 #
 # You can also note that `~~` does not perform start/end checking
 #  (meaning the regexp can be matched with just one char of the string),
 #  we're going to explain later how you can do it.
 
-# In Perl 6, you can have any alphanumeric as a literal, everything else has to be escaped,
-#  using a backslash or quotes.
+# In Perl 6, you can have any alphanumeric as a literal,
+# everything else has to be escaped, using a backslash or quotes.
 say so 'a|b' ~~ / a '|' b /; # `True`. Wouln't mean the same if `|` wasn't escaped
 say so 'a|b' ~~ / a \| b /; # `True`. Another way to escape it.
 
@@ -1137,10 +1244,11 @@ so 'abbbbc' ~~ / a b+ c /; # `True`, matched 4 "b"s
 so 'ac' ~~ / a b* c /; # `True`, they're all optional.
 so 'abc' ~~ / a b* c /; # `True`
 so 'abbbbc' ~~ / a b* c /; # `True`
-so 'aec' ~~ / a b* c /; # `False`. "b"(s) are optional, but can't be something else.
+so 'aec' ~~ / a b* c /; # `False`. "b"(s) are optional, not replaceable.
 
 # - `**` - "Quantify It Yourself".
-# If you squint hard enough, you might understand the why exponentation means quantity.
+# If you squint hard enough, you might understand
+#  why exponentation is used for quantity.
 so 'abc' ~~ / a b ** 1 c /; # `True` (exactly one time)
 so 'abc' ~~ / a b ** 1..3 c /; # `True` (one to three times)
 so 'abbbc' ~~ / a b ** 1..3 c /; # `True`
@@ -1151,13 +1259,14 @@ so 'abbbbbbc' ~~ / a b ** 3..* c /; # `True` (infinite ranges are okay)
 # Group: you can group parts of your regexp with `[]`.
 # These groups are *not* captured (like PCRE's `(?:)`).
 so 'abc' ~~ / a [ b ] c /; # `True`. The grouping does pretty much nothing
-so 'fooABCABCbar' ~~ / foo [ A B C ] + bar /; # `True`.
-                                              # We match the "abc" 1 or more time.
-                                              # (the `+` was applied to the group)
+so 'fooABCABCbar' ~~ / foo [ A B C ] + bar /;
+# The previous line returns `True`.
+# We match the "abc" 1 or more time (the `+` was applied to the group).
 
-# But this does not go far enough, because we can't actually get back what we matched.
+# But this does not go far enough, because we can't actually get back what
+#  we matched.
 # Capture: We can actually *capture* the results of the regexp, using parentheses.
-so 'fooABCABCbar' ~~ / foo ( A B C ) + bar /; # `True`. (we keep `so` here and use `$/` below)
+so 'fooABCABCbar' ~~ / foo ( A B C ) + bar /; # `True`. (using `so` here, `$/` below)
 
 # So, starting with the grouping explanations.
 # As we said before, our `Match` object is available as `$/`:
@@ -1165,13 +1274,15 @@ say $/; # Will print some weird stuff (we'll explain) (or "Nil" if nothing match
 
 # As we also said before, it has array indexing:
 say $/[0]; #=> ｢ABC｣ ｢ABC｣
-           # These weird brackets are `Match` objects. So here, we have an array of that.
-say $0; # the same as above.
+           # These weird brackets are `Match` objects.
+           # Here, we have an array of these.
+say $0; # The same as above.
 
 # Our capture is `$0` because it's the first and only one capture in the regexp.
 # You might be wondering why it's an array, and the answer is simple:
 # Some capture (indexed using `$0`, `$/[0]` or a named one) will be an array
-#  IF it can have more than one element (so, with `*`, `+` and any `**`, but not with `?`).
+#  IFF it can have more than one element
+#  (so, with `*`, `+` and any `**`, but not with `?`).
 # Let's use examples to see that:
 so 'fooABCbar' ~~ / foo ( A B C )? bar /; # `True`
 say $/[0]; #=> ｢ABC｣
@@ -1206,8 +1317,9 @@ sub MAIN($name) { say "Hello, you !" }
 #      t.pl <name> 
 
 # And since it's a regular Perl 6 sub, you can haz multi-dispatch:
-# (using a "Bool" for the named argument so that we get `--replace` instead of `--replace=`)
-subset File of Str where *.IO.d; # convert to IO object, then check the file exists
+# (using a "Bool" for the named argument so that we get `--replace`
+#  instead of `--replace=1`)
+subset File of Str where *.IO.d; # convert to IO object to check the file exists
 
 multi MAIN('add', $key, $value, Bool :$replace) { ... }
 multi MAIN('remove', $key) { ... }
@@ -1218,12 +1330,15 @@ multi MAIN('import', File, Str :$as) { ... } # omitting parameter name
 #      t.pl [--replace] add <key> <value> 
 #      t.pl remove <key>
 #      t.pl [--as=<Str>] import (File)
-# As you can see, this is *very* powerful. It even went as far as to show inline the constants.
-# (the type is only displayed if 1. there's no argument name 2. it's a named argument)
+# As you can see, this is *very* powerful.
+# It even went as far as to show inline the constants.
+# (the type is only displayed if the argument is `$`/is named)
 ```
 
 If you want to go further, you can:
+
  - Read the [Perl 6 Advent Calendar](http://perl6advent.wordpress.com/). This is probably the greatest source of Perl 6 information, snippets and such.
  - Come along on `#perl6` at `irc.freenode.net`. The folks here are always helpful.
  - Check the [source of Perl 6's functions and classes](https://github.com/rakudo/rakudo/tree/nom/src/core). Rakudo is mainly written in Perl 6 (with a lot of NQP, "Not Quite Perl", a Perl 6 subset easier to implement and optimize).
  - Read the [Synopses](perlcabal.org/syn). They explain it from an implementor point-of-view, but it's still very interesting.
+