WhileDB

rust implementation of While-DB, the programming language used in SJTU CS2612 (2022 Fall) Attachment 1014

TODO

• find a way to omit ; after } currently unable to add ;, however

• add function

• make any expression callable (currently only ident callable)

• add class and method

• add [ ] to represent array and getitem

• add string

• add interpreter or compiler

  any object (including the program state) can be represented as Any, pointer to WdAny WdAny is either Object or Function Object has 2 fields buildin (store buildin types or Not) and attrs(a string to Any map) Function is either build-in or defined

  state store

  • types (object with "__name__" => typename, and "__method_name__" => method function)
  • instances (object with "__type__" => type object)
  • functions ...

  state = { <locals>, "..": {<nonlocals>} } 😎, only do this in DefinedFunction (buildin function do not have locals)

  call an expression

  • expr is a expr0.ident and expr is a instance (__type__ is not type), args = [expr0, *args] plan to check this via add flags on return value of eval pub fn eval(expr: Rc<Expr>, state: Any) -> Result<(Any, Option<Any>)> etc.

    plan to check break, continue, return the same way.

  • expr is a WdAny::Function, original args
  • expr if a Object
    • with __init__ self-attr, args = [new_obj (with __type__ => this expr), *args]
    • with __call__ self-attr, original args
    • with __call__ attr found from __type__ attr, args = [this expr, *args]

Future Work

• python binding: WhileDB.rs
• wasm