?? !!
syntax
ternary logic
https://docs.raku.org/language/operators#infix_??_!!
Depending on the condition (before the C<??>) produces the
value of the expression between C<??> and C<!!> (if true)
or the expression after C<!!> if the condition was B<not>
true.

if
syntax statement
execute block if condition is true
https://docs.raku.org/language/control#if
First of one or more blocks of conditional execution.  Will
execute the block if the condition was true.

elsif
syntax statement
execute block if condition is true and previous false
https://docs.raku.org/language/control#else/elsif
Followup of C<if> or another C<elsif>, checked if the first
(or previous) condition evaluated to false.  Executes the
associated block if true.

else
syntax statement
execute block if none of previous blocks were executed
https://docs.raku.org/language/control#else/elsif
Final followup of C<if>, C<elsif>, C<with> or C<orwith>.  Executes
the associated block if none of the previous blocks were executed.

unless
syntax statement
execute block if condition is false
https://docs.raku.org/language/control#unless
A single block of conditional execution, to be executed if the
given condition evaluates to false.

with
syntax statement topic
execute block if value is defined, and set topic
https://docs.raku.org/language/control#with_orwith_without
Start of one or more blocks of conditional execution.  Depending
on whether the expression evaluates to a defined value, the block
will be executed with the topic (C<$_>) set to the value inside
the block.

orwith
syntax statement
execute block if value is defined and previous not, and set topic
https://docs.raku.org/language/control#with_orwith_without
Followup of C<with> or another C<orwith>, checked if the first
(or previous) expressions did not produce a defined value.
Depending on whether the expression evaluates to a defined value,
the block will be executed with the topic (C<$_>) set to the value
inside the block.

without
syntax statement
execute block if value is not defined, and set topic
https://docs.raku.org/language/control#with_orwith_without
A single block of conditional execution, to be executed if the
given expression evaluates to undefined value.  Sets the topic
(C<$_>) with the value inside the block.

once
syntax statement thunky
execute given block / thunk only once
https://docs.raku.org/language/control#once
Execute the given block once int the given scope.  The code:
=begin code :lang<raku>
once say "foo";
=end code
is equivalent to:
=begin code :lang<raku>
state $flag;
say "foo" unless $flag++;
=end code


contains the statement syntaxes to indicate conditional execution
of code.
