4 ms·
i think the symbolics 3600 had 4 or 8 bit for tags, ocaml is borrowing some more lisp ideas.
by auvi 12y ago
i think the symbolics 3600 had 4 or 8 bit for tags, ocaml is borrowing some more lisp ideas.
- FullyFunctional 12y agoThe ideas behind pointer tagging have been applied and reinvented an astonishingly amount of times, see Knuth and any number of book on the implementation of functional programming languages. To claim symbolics or Lisp invented everything is a bit silly and inaccurate. OT: Thanks to Don Stewart for the two interesting links: https://ghc.haskell.org/trac/ghc/wiki/Commentary/Rts/Storage/HeapObjects https://ghc.haskell.org/trac/ghc/wiki/Commentary/Rts/Storage... https://ghc.haskell.org/trac/ghc/wiki/Commentary/Rts/HaskellExecution/PointerTagging https://ghc.haskell.org/trac/ghc/wiki/Commentary/Rts/Haskell...
- _delirium 12y agoI believe the basic idea dates to the Rice architecture of the late 1950s and 1960s [1]. Although there it wasn't just a programming language implementation technique, but a proposal conceived as a full-on alternative to the Von Neumann architecture [2]. Tagged values as a programming-language implementation technique do seem to take off more towards the early 1970s, though, with the ex-MIT team that would produce the Lisp Machine, and the Xerox team that would produce Smalltalk, both using tagged values prominently. [1] https://en.wikipedia.org/wiki/Rice_Institute_Computer https://en.wikipedia.org/wiki/Rice_Institute_Computer [2] A somewhat later (1973) paper referenced above: http://www.feustel.us/Feustel%20&%20Associates/Advantages.pdf http://www.feustel.us/Feustel%20&%20Associates/Advantages.pd...
- ScottBurson 12y agoMinor correction: the Lisp Machine was created at MIT by MIT staff. Only after it existed did the commercial entities get spun off.
- lispm 12y agoMost Lisp implementations use tag bits. The Symbolics does support it in hardware, though.