[BACK]Return to pxin4.n CVS log [TXT][DIR] Up to [cvs.NetBSD.org] / src / share / doc / papers / px

Annotation of src/share/doc/papers/px/pxin4.n, Revision 1.3

1.3     ! agc         1: .\"    $NetBSD: pxin4.n,v 1.2 1998/01/09 06:41:57 perry Exp $
1.2       perry       2: .\"
1.1       cgd         3: .\" Copyright (c) 1979 The Regents of the University of California.
                      4: .\" All rights reserved.
                      5: .\"
                      6: .\" Redistribution and use in source and binary forms, with or without
                      7: .\" modification, are permitted provided that the following conditions
                      8: .\" are met:
                      9: .\" 1. Redistributions of source code must retain the above copyright
                     10: .\"    notice, this list of conditions and the following disclaimer.
                     11: .\" 2. Redistributions in binary form must reproduce the above copyright
                     12: .\"    notice, this list of conditions and the following disclaimer in the
                     13: .\"    documentation and/or other materials provided with the distribution.
1.3     ! agc        14: .\" 3. Neither the name of the University nor the names of its contributors
1.1       cgd        15: .\"    may be used to endorse or promote products derived from this software
                     16: .\"    without specific prior written permission.
                     17: .\"
                     18: .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     19: .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     20: .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     21: .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     22: .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     23: .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     24: .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     25: .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     26: .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     27: .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     28: .\" SUCH DAMAGE.
                     29: .\"
                     30: .\"    @(#)pxin4.n     5.2 (Berkeley) 4/17/91
                     31: .\"
                     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.

CVSweb <webmaster@jp.NetBSD.org>