Expressions Grammar Meeting

29. OCT 2010
    

14:30 to 16:30

Participants

• haf
• uru
• cmot
• chsch

Modifications of uru

• Float rule
  • Not shadows INT
  • Accepted

• NegExpression?
  • E.g., -(a+b) or -v
  • Serialization test cases needed
  • Accepted (if serialization possible)

• Renamings:
  • int 2 integer
  • bool 2 boolean
  • string?
  • double?
  • Extend Enum type
  • Be careful with omitting default values when overwriting rule

• DivExpression?
  • Always use braces around DivExpression?
  • This is not what we want: Better change ActionsGrammar?
  • Good reason for separate Add, Sub, Mult and DivExpression? (operator is overridden)
  • delay / E causes problem!
  • better require: delay tick / E

• Count Delays
  • Should normally allow integer expression (meta model change?)

• Operator Precedences
  • *, /, %

• Signal Declaration Problem
  • Still a limitation of Xtext
  • IsOutput? flag cannot be 'stuffed' into signal declared after
  • Alternative to four lists: Four classes of signals and postprocessing
    • Problem when serializing?
  • Alternative: Scope w/ synchronized Signal and InterfaceDecl? class
  • Alternative: InterfaceDecl? as Annotation
  • Alternative: NO (static) Signal class, dynamically Xtend the meta model to generate derived information
    • Consequences in graphical editor: No graphic objects
    • Utility functions for Scope, e.g., getSignals(), addSignal(), ...
    • Alternative: Utility function as operations directly in EMF/Java (implement stubs)
  • First steps:
    1. Leave Signal class in meta model for compatibility aspects
    2. Uru adds InterfaceDecl?
    3. Add utility functions
    4. Remove Signal if all projects use the utility functions