Open, extensible composition models

Open, extensible composition models by Ian Piumarta.

Did VPRI just enter the FEXPR game?

The evaluator corrects several semantic inadequacies of LISP (described by Stoyan [5]) and is metacircular (written in the language it evaluates). The language provides:

• lists and atomic values, including symbols
• primitive functions called SUBRs
• symbolic functions (closures) called EXPRs
• a FIXED object that encapsulates another applicable value and prevents argument evaluation
• predicates to discriminate between the above types
• built-in SUBRs to access the contents of these values
• a way to call the primitive behaviour of a SUBR
• a quotation mechanism to prevent evaluation of literals

(my emphasis)

More later. HT @CraigOverend.

Update: Oh, also new: Alan Kay et al.: STEPS Toward Espressive [sic] Programming Systems, 2011 Progress Report HT hack the planet in exile