1 files changed, 75 insertions, 0 deletions
diff --git a/puppet/modules/stdlib/lib/puppet/parser/functions/is_numeric.rb b/puppet/modules/stdlib/lib/puppet/parser/functions/is_numeric.rb
new file mode 100644
index 00000000..e7e1d2a7
--- /dev/null
+++ b/puppet/modules/stdlib/lib/puppet/parser/functions/is_numeric.rb
@@ -0,0 +1,75 @@
+#
+# is_numeric.rb
+#
+
+module Puppet::Parser::Functions
+  newfunction(:is_numeric, :type => :rvalue, :doc => <<-EOS
+Returns true if the given argument is a Numeric (Integer or Float),
+or a String containing either a valid integer in decimal base 10 form, or
+a valid floating point string representation.
+
+The function recognizes only decimal (base 10) integers and float but not
+integers in hex (base 16) or octal (base 8) form.
+
+The string representation may start with a '-' (minus). If a decimal '.' is used,
+it must be followed by at least one digit.
+
+Valid examples:
+
+  77435
+  10e-12
+  -8475
+  0.2343
+  -23.561e3
+    EOS
+  ) do |arguments|
+
+    if (arguments.size != 1) then
+      raise(Puppet::ParseError, "is_numeric(): 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 invalid octal numbers or
+    # numbers prefixed with multiple 0's (except in hex numbers)
+    #
+    # TODO these parameters should be constants but I'm not sure
+    # if there is no risk to declare them inside of the module
+    # Puppet::Parser::Functions
+
+    # TODO decide if this should be used
+    # HEX numbers like
+    # 0xaa230F
+    # 0X1234009C
+    # 0x0012
+    # -12FcD
+    #numeric_hex = %r{^-?0[xX][0-9A-Fa-f]+$}
+
+    # TODO decide if this should be used
+    # OCTAL numbers like
+    # 01234567
+    # -045372
+    #numeric_oct = %r{^-?0[1-7][0-7]*$}
+
+    # Integer/Float numbers like
+    # -0.1234568981273
+    # 47291
+    # 42.12345e-12
+    numeric = %r{^-?(?:(?:[1-9]\d*)|0)(?:\.\d+)?(?:[eE]-?\d+)?$}
+
+    if value.is_a? Numeric or (value.is_a? String and (
+      value.match(numeric) #or
+    #  value.match(numeric_hex) or
+    #  value.match(numeric_oct)
+    ))
+      return true
+    else
+      return false
+    end
+  end
+end
+
+# vim: set ts=2 sw=2 et :