ExpressionEvaluator Todo List

ExpressionEvaluator can already do some fun things, but it could do more. Here is just a small list of ideas and todo stuff (maybe some will never be done, But it's a place to keep track of ideas). It's a kind of not dated roadmap.

More customization

• Customization of the script evaluation part

More C# like things support

• Manage Tuples
• Add nameof keyword
• Subscribe to event
• Manage switch case

Optimization and/or doing things better

• Speed up evaluations
  • Caching things and consider using expression tree or other intermediate format. (See)
  • Caching Properties delegates (Do not improve perfs significantly)
• Better variables management
  • Declare struct and valuetypes without new keyword
  • Scope variables to code blocks (add an option for retrocompatibility)
• Line and (position) in script exceptions
• More self explained exceptions
• Add standard syntax for method declaration (for now see issue #72 Declare methods in scripts)

Other

• Create Func<> or Action<>
• Return a Func<> or an Action<>
• Validate code before evaluate (Hard to do without evaluating things)

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Done

• Manage ref method args (see #83)
• Manage in method args (see #83)
• Manage out method args (see #83)
• Manage params methods args (see #83)
• Add a Context object in addition to Variables Dictionary to allow direct access to it's methods, fields and properties
• Manage List<>.ForEach
• Transform an internal lambda to Action<> or Func<> when needed (To allow writing List<>.ForEach(x => {}))
• Typed variables (In version 1.4.3.0 See Declare and init variables in scripts
• Generic types inference (Optimistic way to inferate. Only looking backward for generics in the stack)
• Add an optional var keyword for variables init. (Better for copy paste with C# code)
• Manage structs assignation
• Option to force integer eval as double
• Manage numbers decimal separator and functions arguments separators
• Manage sizeof keyword
• Binary numbers
• Hexadecimal numbers
• ++ and -- as prefix operators
• Dictionary initializers
• Collection initializers
• Objects initializers
• throw and try catch exception
• Manage ExpendoObject
• Manage calling of Action and Func delegates
• Manage ++ and -- for indexing
• Manage assignation to indexer
• Manage do while
• Properties set assignation
• Manage foreach
• Manage continue keyword
• Manage break keyword
• Manage blocks in lambda body
• Manage return keyword
• Manage comments // and /* */
• Manage Evaluate<type>(calc)
• Manage chars
• On the fly properties and methods evaluation
• Manage Generic functions and types with <>
• Manage ?: operator
• Manage new Keyword
• Manage multi line mode with ;? and = ++`...
• Manage blocks like if for while...

Optimization and/or doing things better

• Speed up evaluations
  • Manage inline namespaces faster
  • Option for caching namespace resolution
  • Option for caching type resolution
  • [Kept as this] Manage object creation faster (Activator.CreateInstance finally not so slow comparing to others strategy)

More customization

• Custom operators (see #27 and Advanced Customization and Hacking)
  • On the fly operators
  • Operators Dictionary easy customisation
  • Add a way to allow aliases for existing operators like Or, And
  • Add a way to add some custom operators and corresponding implementations
  • Flexible length of the operators
  • Types : multiple operands vs Single operands (Maybe start with only 2 operands operators)
  • Take care of operators precedences (priorities)
• Add generic types in VariableEvaluationEventArg and FunctionEvaluationEventArg for on the fly evaluations (A list of types when using <>)
• On the fly static methods and/or property
• Better onthe fly events priorities management with other evaluations (By adding 2 Pre events See #35)
• On the fly parsing (event with current expression,ref parsing position and the stack)

Will not (or can not) be done for now

• Find a way to manage extensions methods without the need to declaring the static type and without beeing too slow (snippet to add all extensions class provided here)