Big signature return type unification.

This commit affects all signatures that exist in the type documentation: it replaces "returns " occurences with "-->" form.

See #1024 (comment) for explanations.

doc/Type/Any.pod6

@@ -36,7 +36,7 @@ Many built-in types override this for more specific comparisons
 
 Defined as:
 
-    method any() returns Junction:D
+    method any(--> Junction:D)
 
 Interprets the invocant as a list and creates an
 C<any>-L<Junction|/type/Junction> from it.
@@ -48,7 +48,7 @@ C<any>-L<Junction|/type/Junction> from it.
 
 Defined as:
 
-    method all() returns Junction:D
+    method all(--> Junction:D)
 
 Interprets the invocant as a list and creates an
 C<all>-L<Junction|/type/Junction> from it.
@@ -60,7 +60,7 @@ C<all>-L<Junction|/type/Junction> from it.
 
 Defined as:
 
-    method one() returns Junction:D
+    method one(--> Junction:D)
 
 Interprets the invocant as a list and creates a
 C<one>-L<Junction|/type/Junction> from it.
@@ -72,7 +72,7 @@ C<one>-L<Junction|/type/Junction> from it.
 
 Defined as:
 
-    method none() returns Junction:D
+    method none(--> Junction:D)
 
 Interprets the invocant as a list and creates a
 C<none>-L<Junction|/type/Junction> from it.
@@ -103,8 +103,8 @@ into the newly created Array.
 
 Defined as:
 
-    multi sub    reverse(*@list ) returns List:D
-    multi method reverse(List:D:) returns List:D
+    multi sub    reverse(*@list  --> List:D)
+    multi method reverse(List:D: --> List:D)
 
 Returns a list with the same elements in reverse order.
 
@@ -150,7 +150,7 @@ occur over C<(SELF,)> (if C<:$item> is set) or C<SELF>.
 
 Defined as:
 
-    method deepmap(&block) returns List is nodal
+    method deepmap(&block --> List) is nodal
 
 C<deepmap> will apply C<&block> to each element and return a new C<List> with
 the return values of C<&block>, unless the element does the C<Iterable> role.
@@ -223,7 +223,7 @@ Interprets the invocant as a list, and returns the last index of that list.
 
 =head2 method pairup
 
-    method pairup() returns List
+    method pairup(--> List)
 
 Interprets the invocant as a list, and constructs a list of
 L<pairs|/type/Pair> from it, in the same way that assignment to a

doc/Type/Array.pod6

@@ -36,8 +36,8 @@ Example:
 
 Defined as:
 
-    multi sub    push(Array:D, **@values) returns Array:D
-    multi method push(Array:D: **@values) returns Array:D
+    multi sub    push(Array:D, **@values --> Array:D)
+    multi method push(Array:D: **@values --> Array:D)
 
 Adds the C<@values> to the end of the array, and returns the modified list.
 Fails for infinite arrays.
@@ -116,8 +116,8 @@ Example:
 
 Defined as:
 
-    multi sub    unshift(Array:D, **@values) returns Array:D
-    multi method unshift(Array:D: **@values) returns Array:D
+    multi sub    unshift(Array:D, **@values --> Array:D)
+    multi method unshift(Array:D: **@values --> Array:D)
 
 Adds the C<@values> to the start of the array, and returns the modified array.
 Fails if C<@values> is infinite.
@@ -157,8 +157,8 @@ Example:
 
 Defined as:
 
-    multi sub    splice(@list,  $start, $elems?, *@replacement) returns Array
-    multi method splice(Array:D $start, $elems?, *@replacement) returns Array
+    multi sub    splice(@list,  $start, $elems?, *@replacement --> Array)
+    multi method splice(Array:D $start, $elems?, *@replacement --> Array)
 
 Deletes C<$elems> elements starting from index C<$start> from the C<Array>,
 returns them and replaces them by C<@replacement>. If C<$elems> is omitted,

doc/Type/Attribute.pod6

@@ -36,7 +36,7 @@ The usual way to obtain an object of type C<Attribute> is by introspection:
 
 Defined as:
 
-    method name(Attribute:D:) returns Str:D
+    method name(Attribute:D: --> Str:D)
 
 Returns the name of the attribute.  Note that this is always the private name,
 so if an attribute is declared as C<has $.a>, the name returned is C<$!a>.
@@ -51,7 +51,7 @@ so if an attribute is declared as C<has $.a>, the name returned is C<$!a>.
 
 Defined as:
 
-    method package(Attribute:D:) returns Mu:U
+    method package(Attribute:D: --> Mu:U)
 
 Returns the package (class/grammar/role) to which this attribute belongs.
 
@@ -65,7 +65,7 @@ Returns the package (class/grammar/role) to which this attribute belongs.
 
 Defined as:
 
-    method has_accessor(Attribute:D:) returns Bool:D
+    method has_accessor(Attribute:D: --> Bool:D)
 
 Returns C<True> if the attribute has a public accessor method.
 
@@ -82,7 +82,7 @@ Returns C<True> if the attribute has a public accessor method.
 
 Defined as:
 
-    method readonly(Attribute:D:) returns Bool:D
+    method readonly(Attribute:D: --> Bool:D)
 
 Returns C<True> for readonly attributes, which is the default.
 Returns C<False> for attributes marked as C<is rw>.
@@ -100,7 +100,7 @@ Returns C<False> for attributes marked as C<is rw>.
 
 Defined as:
 
-    method type(Attribute:D:) returns Mu
+    method type(Attribute:D: --> Mu)
 
 Returns the type constraint of the attribute.
 

doc/Type/Backtrace/Frame.pod6

@@ -14,7 +14,7 @@ A single backtrace frame. It identifies a location in the source code.
 
 Defined as:
 
-    method file(Backtrace::Frame:D) returns Str
+    method file(Backtrace::Frame:D --> Str)
 
 Returns the file name.
 
@@ -26,7 +26,7 @@ Returns the file name.
 
 Defined as:
 
-    method line(Backtrace::Frame:D) returns Int
+    method line(Backtrace::Frame:D --> Int)
 
 Returns the line number (line numbers start to count from 1).
 
@@ -50,7 +50,7 @@ Returns the code object into which C<.file> and C<.line> point, if available.
 
 Defined as:
 
-    method subname(Backtrace::Frame:D) returns Str
+    method subname(Backtrace::Frame:D --> Str)
 
 Returns the name of the enclosing subroutine.
 
@@ -62,7 +62,7 @@ Returns the name of the enclosing subroutine.
 
 Defined as:
 
-    method is-hidden(Backtrace::Frame:D) returns Bool:D
+    method is-hidden(Backtrace::Frame:D --> Bool:D)
 
 Returns C<True> if the frame is marked as hidden with the
 C<is hidden-from-backtrace> trait.
@@ -75,7 +75,7 @@ C<is hidden-from-backtrace> trait.
 
 Defined as:
 
-    method is-routine(Backtrace::Frame:D) returns Bool:D
+    method is-routine(Backtrace::Frame:D --> Bool:D)
 
 Return C<True> if the frame point into a routine (and not
 into a mere L<Block>).
@@ -88,7 +88,7 @@ into a mere L<Block>).
 
 Defined as:
 
-    method is-setting(Backtrace::Frame:D) returns Bool:D
+    method is-setting(Backtrace::Frame:D --> Bool:D)
 
 Returns C<True> if the frame is part of a setting.
 

doc/Type/Bag.pod6

@@ -97,7 +97,7 @@ with detailed explanations.
 
 =head2 sub bag
 
-    sub bag(*@args) returns Bag
+    sub bag(*@args --> Bag)
 
 Creates a new C<Bag> from C<@args>.