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comparison examples/mpp/token.cpp @ 0:13d2b8934445

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Import AnaGram (near-)release tree into Mercurial.
author David A. Holland
date Sat, 22 Dec 2007 17:52:45 -0500
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-1:000000000000 0:13d2b8934445
1 /*
2 * AnaGram, a System for Syntax Directed Programming
3 * C Macro preprocessor
4 * Token handling module
5 *
6 * Copyright 1993 Parsifal Software. All Rights Reserved.
7 *
8 * This software is provided 'as-is', without any express or implied
9 * warranty. In no event will the authors be held liable for any damages
10 * arising from the use of this software.
11 *
12 * Permission is granted to anyone to use this software for any purpose,
13 * including commercial applications, and to alter it and redistribute it
14 * freely, subject to the following restrictions:
15 *
16 * 1. The origin of this software must not be misrepresented; you must not
17 * claim that you wrote the original software. If you use this software
18 * in a product, an acknowledgment in the product documentation would be
19 * appreciated but is not required.
20 * 2. Altered source versions must be plainly marked as such, and must not be
21 * misrepresented as being the original software.
22 * 3. This notice may not be removed or altered from any source distribution.
23 */
24
25 #include "token.h"
26
27
28 // Constructor for token_accumulator
29
30 token_accumulator::token_accumulator(int nc, int nx) {
31 cs = new token[nc]; // token storage
32 xs = new unsigned[nx]; // index storage (for levels)
33 csx = 0; // next free token
34 csmax = nc - 1; // leave room for termination eof
35 xsx = xsmax = nx; // pre-decrement, post-increment
36 xs[--xsx] = csx; // initial token string
37 }
38
39
40 // Destructor for token_accumulator
41
42 token_accumulator::~token_accumulator() {
43 delete[] cs;
44 delete[] xs;
45 }
46
47
48 // Reset token_accumulator
49
50 token_accumulator &reset(token_accumulator &t) {
51 t.csx = 0;
52 t.xsx = t.xsmax;
53 t.xs[--t.xsx] = t.csx;
54 return t;
55 }
56
57 // Push data on token_accumulator
58
59 token_sink &token_accumulator::operator << (token *tp) {
60 while (tp->id != END_OF_FILE) *this << *tp++;
61 return *this;
62 }
63
64
65 // Pop data from token_accumulator
66
67 token_accumulator &token_accumulator::operator >> (token &c) {
68 assert(csx > xs[xsx]); // a token to pop
69 c = cs[--csx]; // pop token
70 return *this;
71 }
72
73
74 // Access data in token_accumulator
75 /*
76 token &token_accumulator::operator [](unsigned i) {
77 assert(i < csx - xs[xsx]); // index in bounds
78 return cs[csx - i - 1]; // identify token
79 }
80 */
81
82 // Concatenate token strings in token_accumulator
83
84 token_accumulator &concat(token_accumulator &s) {
85 assert(s.xsx < s.xsmax - 1); // at least two strings
86 s.xsx++;
87 return s;
88 }
89
90
91 // Make permanent copy of token string
92
93 token *copy(token_accumulator &s) {
94 int n = s.csx - s.xs[s.xsx] + 1;
95 token *c = new token[n];
96 token null;
97 null.id = END_OF_FILE;
98 null.handle = 0;
99 s.cs[s.csx] = null;
100 memcpy(c, (token *) s, n*sizeof(token));
101 return c;
102 }
103
104
105 // Send token string to token translator
106
107 token_sink &token_translator::operator << (token *tp) {
108 while (tp->id != END_OF_FILE) *this << *tp++;
109 return *this;
110 }