1 .\" Copyright (c) 1979 The Regents of the University of California.
2 .\" All rights reserved.
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5 .\" modification, are permitted provided that the following conditions
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14 .\" This product includes software developed by the University of
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20 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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32 .\" @(#)pxin0.n 5.2 (Berkeley) 4/17/91
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39 PX Implementation Notes
41 Version 2.0 \- January, 1979
47 Computer Science Division
48 Department of Electrical Engineering and Computer Science
49 University of California, Berkeley
50 Berkeley, California 94720
54 is designed for interactive instructional use and runs on the
58 executes the Pascal binaries generated by the Pascal translator
63 PX Implementation Notes
65 describe the general organization of
67 detail the various operations of the interpreter,
68 and describe the file input/output structure.
69 Conclusions are given on the viability of an interpreter
70 based approach to language implementation for an instructional environment.
78 PX Implementation Notes
80 have been updated from the original
82 implementation notes to reflect the interpreter that runs on the
84 These notes consist of four major parts.
85 The first part outlines the general organization of
87 Section 2 describes the operations (instructions) of the interpreter
88 while section 3 focuses on input/output related activity.
89 A final section gives conclusions about the viability of an interpreter
90 based approach to language implementation for instruction.
92 Related Berkeley Pascal documents
95 .I "PXP Implementation Notes"
96 give details of the internals of the execution profiler
98 parts of the interpreter related to
100 are discussed in section 2.10.
101 A paper describing the syntactic error recovery mechanism used in
103 was presented at the ACM Conference on Compiler Construction
104 in Boulder Colorado in August, 1979.
114 opcode mapping of the original
116 that was designed and implemented by Ken Thompson,
117 with extensive modifications and additions
120 Without their work, this
122 system would never have existed.
123 These notes were first written by William Joy for the
126 We would also like to thank our faculty advisor Susan L. Graham
127 for her encouragement,
128 her helpful comments and suggestions
131 and her excellent editorial assistance.
133 \*(dg\ The financial support of the National Science Foundation under grants
134 MCS74-07644-A03 and MCS78-07291
135 and of an \s-2IBM\s0 Graduate Fellowship are gratefully acknowledged.
138 \*(dd\ The financial support of a Howard Hughes Graduate
139 Fellowship is gratefully acknowledged.