share/doc/papers/px/pxin4.n

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  30 .\"     @(#)pxin4.n     5.2 (Berkeley) 4/17/91
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  32 .if !\n(xx .so tmac.p
  33 .nr H1 3
  34 .if n .ND
  35 .NH
  36 Conclusions
  37 .PP
  38 It is appropriate to consider,
  39 given the amount of time invested in rewriting the interpreter,
  40 whether the time was well spent, or whether a code-generator
  41 could have been written with an equivalent amount of effort.
  42 The Berkeley Pascal system is being modified to interface
  43 to the code generator of the portable C compiler with
  44 not much more work than was involved in rewritting
  45 .I px .
  46 However this compiler will probably not supercede the interpreter
  47 in an instructional environment as the
  48 necessary loading and assembly processes will slow the
  49 compilation process to a noticeable degree.
  50 This effect will be further exaggerated because
  51 student users spend more time in compilation than in execution.
  52 Measurements over the course of a quarter at Berkeley with a mixture
  53 of students from beginning programming to upper division compiler
  54 construction show that the amount of time in compilation exceeds the amount
  55 of time spent in the interpreter, the ratio being approximately 60/40.
  56 .PP
  57 A more promising approach might have been a throw-away code generator
  58 such as was done for the
  59 .SM
  60 WATFIV
  61 .NL
  62 system.
  63 However the addition of high-quality post-mortem and interactive
  64 debugging facilities become much more difficult to provide than
  65 in the interpreter environment.