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> Turing-completeness, of course. Lots of useful programs can be written without turing completeness. It can be useful, but only for a limited problem domain.

• peter-fogg 14y ago
  It actually can have some benefits -- a language without any unbounded loops or recursion isn't Turing-complete, but you do get a static guarantee of termination. NASA, for example, writes much of their C code only with bounded recursion. So they can't compute some things, but they can be sure that the Mars lander never gets stuck in an infinite loop.
  • arianvanp 14y ago
    have you got any sources telling about this? I can't seem to find any. Would be a nice read
    • Bjartr 14y ago
      Here's the official NASA JPL C coding standard http://lars-lab.jpl.nasa.gov/JPL_Coding_Standard_C.pdf http://lars-lab.jpl.nasa.gov/JPL_Coding_Standard_C.pdf Page 10 describes loop bounds and recursion limitations.
• arethuza 14y ago
  "Lots of useful programs can be written without turing completeness." Including Bitcoin transactions - I learned this from elsewhere on HN today. FYI: https://en.bitcoin.it/wiki/Script https://en.bitcoin.it/wiki/Script
  • martindale 14y ago
    Fascinating. What is this?
    • arethuza 14y ago
      I saw a reference to Bitcoin transactions embedding executable content in another thread and was slightly taken aback: https://news.ycombinator.com/item?id=5496740 https://news.ycombinator.com/item?id=5496740