Make rules syntax user-friendly

[samirketema]

Proposed syntax:

["length", "field", "password", "GREATER_THAN", "4"]

1. Keep evaluating operands left to right until a value is reduced from a group of strings (in this case, "length", "field", "password" all represent one value).
2. Once operands are reduced to values, apply operators to values:

• Comparisons: [value1, EQUAL_TO, value2] -> value1 === value2
• Regular expressions: [value1, REGEX, value2 ] -> new RegExp(value1).test(value2)
• Length: [LENGTH, value1] -> length(value1)

[samirketema]

This proposal is for infix notation, which would be harder to parse. Reducing to an array of prefix or postfix would make it easier to parse.