Fix #3871 - Add the 'in' operator

This operator allows to find if the left operand is in the right one.
The left operand must be resort to a string, but the right operand can be:
* a string
* an array
* a hash (the search is done on the keys)

This syntax can be used in any place where an expression is supported.

Syntax:
$eatme = 'eat'
if $eatme in ['ate', 'eat'] {
...
}

$value = 'beat generation'
if 'eat' in $value {
  notice("on the road")
}

Signed-off-by: Brice Figureau <brice-puppet@daysofwonder.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/lib/puppet/parser/ast/in_operator.rb b/lib/puppet/parser/ast/in_operator.rb
new file mode 100644
index 000000000..0f543af9b
--- /dev/null
+++ b/lib/puppet/parser/ast/in_operator.rb
@@ -0,0 +1,26 @@
+require 'puppet'
+require 'puppet/parser/ast/branch'
+
+class Puppet::Parser::AST
+    class InOperator < AST::Branch
+
+        attr_accessor :lval, :rval
+
+        # Returns a boolean which is the result of the 'in' operation
+        # of lval and rval operands
+        def evaluate(scope)
+
+            # evaluate the operands, should return a boolean value
+            lval = @lval.safeevaluate(scope)
+            unless lval.is_a?(::String)
+                raise ArgumentError, "'#{lval}' from left operand of 'in' expression is not a string"
+            end
+
+            rval = @rval.safeevaluate(scope)
+            unless rval.respond_to?(:include?)
+                raise ArgumentError, "'#{rval}' from right operand of 'in' expression is not of a supported type (string, array or hash)"
+            end
+            return rval.include?(lval)
+        end
+    end
+end