TODO.md

add the ability to do inter argument validation

eg imagine

field( first : Int, after : ID, last : Int, before : ID)

can we do a validation rule where we require first+after or last + before but not all 4 together??

Currently the rules are single argument specific - we would need field specific rules

naming

Since we take inspiration from javax validation perhaps we should use the name Constraint especially for the @directives rules

i18n

We rally should look at using the Hibernate message interpolation code (by building a bridge between our own) and get I18n and EL in messages working for near free

https://docs.jboss.org/hibernate/stable/validator/reference/en-US/html_single/#preface

https://github.com/hibernate/hibernate-validator

Allowing Java EL

Can we allow Java EL so that we can have expressions in rules

   ${validatedValue.length()} > 50

Does this makes sense? What can we do to make this more powerful?

Hibernate Validator uses a form of this to do message interpolation

Could this be the inter argument validation

   field( first : Int, after : ID, last : Int, before : ID) : ObjType
       @Expression( expr="""
           ${ (! empty first && empty last) || (!empty last && empty first) }
       """)

is this powerful or not?

Allow scripting

The Hibernate project allows scripting

   @Script(lang : "javascript", script : "_this.startDate.before(_this.endDate)")

Could we do something similar