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>