1 files changed, 45 insertions, 0 deletions
diff --git a/puppet/modules/stdlib/lib/puppet/parser/functions/is_integer.rb b/puppet/modules/stdlib/lib/puppet/parser/functions/is_integer.rb
new file mode 100644
index 00000000..c03d28df
--- /dev/null
+++ b/puppet/modules/stdlib/lib/puppet/parser/functions/is_integer.rb
@@ -0,0 +1,45 @@
+#
+# is_integer.rb
+#
+
+module Puppet::Parser::Functions
+  newfunction(:is_integer, :type => :rvalue, :doc => <<-EOS
+Returns true if the variable passed to this function is an Integer or
+a decimal (base 10) integer in String form. The string may
+start with a '-' (minus). A value of '0' is allowed, but a leading '0' digit may not
+be followed by other digits as this indicates that the value is octal (base 8).
+
+If given any other argument `false` is returned.
+    EOS
+  ) do |arguments|
+
+    if (arguments.size != 1) then
+      raise(Puppet::ParseError, "is_integer(): Wrong number of arguments "+
+        "given #{arguments.size} for 1")
+    end
+
+    value = arguments[0]
+
+    # Regex is taken from the lexer of puppet
+    # puppet/pops/parser/lexer.rb but modified to match also
+    # negative values and disallow numbers prefixed with multiple
+    # 0's
+    #
+    # TODO these parameter should be a constant but I'm not sure
+    # if there is no risk to declare it inside of the module
+    # Puppet::Parser::Functions
+
+    # Integer numbers like
+    # -1234568981273
+    # 47291
+    numeric = %r{^-?(?:(?:[1-9]\d*)|0)$}
+
+    if value.is_a? Integer or (value.is_a? String and value.match numeric)
+      return true
+    else
+      return false
+    end
+  end
+end
+
+# vim: set ts=2 sw=2 et :