Sat Nov 7 09:36:10 CET 2009

Architecture summary

LEAF:  primitive C objects
EX:    C-based expression languages using GCd objects (wrapping leaf objects)
PF/SC: execution model, using EX primitive operations + data model.


  - SC is slow: heap-allocated tree walking interpreter with
    search-based symbol binding.  The upside is that the structure is
    simple: a textbook CEKS machine.

  - EX requires distinction between two modes: 

    * PURE: construction without mutation = GC enabled -> primitives
            might restart on collection

    * LINEAR: mutation without construction = GC disabled.