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fuzion-lang.dev — The Fuzion Language Portal
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Fuzion Front End

  • Limited data flow analysis only, in particular:
    • No check for uninitialized variables
  • No proper name space handling, i.e.,
    • features are visible in all of their outer feature. even if defined in a nested inner scope.
    • Several local vars with equal names in different scopes of the same outer feature will cause errors
  • Limitations on repeated inheritance, in particular
    • no checks that repeatedly inherited features are compatible with respect to their generic parameters
    • no checks that conflicts in inheritance are detected and resolved
    • no means to keep several instances of repeatedly inherited features (e.g., via Eiffel-style renaming)
  • No support to call the original feature from a redefinition (Java's super.f() or Eiffel's repeated inheritance with renaming)
  • No support for feature invariants, loop variants and invariants.
  • No support for pre- and postconditions of redefined features.
  • No support for singleton / once features, need to decide if they are needed and if so, what semantics should they have?
  • Support for threads is being worked on.
  • Support for modules is being worked on.

Fuzion Tool Chain

  • fume Fuzion Middle end does not exist yet
  • fuom Fuzion Optimizer does not exist yet
  • fube Fuzion Back Ends: C Backend (emits C Code), (Interpreter on top of the JVM)

Fuzion Standard Library

  • Is being worked on.


  • Only tested on Firefox 80.0.1 on Ubuntu 18.04.
  • Many hacks