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1.1 root 1: /*
2: * lexio.c 1.4
3: *
4: * Modified Lexical Analyzer I/O Package for Spreadsheet Program `vis'
5: *
6: * A. F. Gettier
7: * Bell Laboratories
8: * Update made 11/1/82 11:12:16
9: * Retrieved 11/15/82 13:22:30
10: */
11: #include <stdio.h>
12: #include "curses.h"
13: #include "vis.h"
14:
15: extern struct qheader Fixup, Depend;
16: extern int COLS, LINES;
17:
18: enum states { FIRST, FFILE, FPEND, OTHER };
19:
20: char Inline[128];
21:
22: static enum states lstate;
23: static char *line=0, unbuf[128];
24: static char buffer[128];
25: static int uncnt=0, first=TRUE;
26: static FILE *fp;
27:
28: /*
29: * Start lex up for this input line
30: * This includes passing the initial line to the
31: * lexical analyzer
32: */
33: void
34: startlex( inbuf )
35: char *inbuf;
36: {
37: lexinit();
38: (void)strcpy( buffer, inbuf );
39: lstate = FIRST;
40: }
41:
42: /*
43: * Reset lex for next line
44: * This routine allows lex to restart as though
45: * it had never been run
46: */
47: void
48: lexinit()
49: {
50: /* set the current line as empty */
51:
52: Inline[0] = '\0';
53: line = 0;
54:
55: /* empty the unput buffer */
56:
57: uncnt = 0;
58:
59: /* flush any fixups */
60:
61: while ( qread( &Fixup ) != 0 );
62:
63: /* turn off the file */
64:
65: /* lstate = OTHER; */
66: }
67:
68: readfile( file )
69: FILE *file;
70: {
71: fp = file;
72: lstate = FPEND;
73: }
74:
75:
76: /*
77: * New input routine for the lexical analyzer
78: */
79: char input()
80: {
81: int i;
82: struct node *t;
83: /*
84: * return stored up characters if present
85: */
86: if ( uncnt > 0 ) {
87: return( unbuf[ --uncnt ] );
88: }
89: /*
90: * Do we need a new buffer?
91: */
92: if ( line == 0 ) {
93: switch( lstate ) {
94: /*
95: * First time in, get the input buffer
96: */
97: case FIRST:
98: (void)strcpy( Inline, cannon( buffer ) );
99: line = buffer;
100: lstate = OTHER;
101: break;
102: /*
103: * Get a line from the file
104: */
105: case FFILE:
106: tryfile:
107: if ( fgets( buffer, 128, fp ) == NULL ) {
108: lstate = OTHER;
109: goto tryother;
110: }
111: for ( i=0; buffer[i]!='\0'; i++ )
112: if ( buffer[i] == '\n' ) {
113: buffer[i] = '\0';
114: break;
115: }
116: (void)cannon( buffer );
117: (void)strcpy( Inline, buffer );
118: line = buffer;
119: lstate = FPEND;
120: break;
121: case FPEND:
122: loop {
123: if ( (t = qread( &Fixup )) == 0 ) {
124: lstate = FFILE;
125: goto tryfile;
126: }
127: if ( t->def == 0 ) continue;
128: strcpy( buffer, t->def );
129: (void)strcpy( Inline, buffer );
130: line = buffer;
131: break;
132: }
133: break;
134: case OTHER:
135: tryother:
136: loop {
137: if ( (t = qread( &Fixup )) == 0 ) {
138: first = TRUE;
139: return( '\0' );
140: }
141: if ( t->def == 0 ) continue;
142: strcpy( buffer, t->def );
143: (void)strcpy( Inline, buffer );
144: line = buffer;
145: break;
146: }
147: }
148: }
149: if ( *line == '#' || *line == ';' || *line == '\0' || *line == '\n' ) {
150: line = 0;
151: return( '\n' );
152: }
153: return( *line++ );
154: }
155: /*
156: * Unput the character
157: */
158: unput( chr )
159: char chr;
160: {
161: unbuf[ uncnt++ ] = chr;
162: }
163: /*
164: * Fold all lower case to upper case
165: */
166: char *foldup( string )
167: char *string;
168: {
169: char *ts;
170: /*
171: * Fold up
172: */
173: ts = string;
174: while ( *ts != '\0' ) {
175: if ( *ts >= 'a' && *ts <= 'z' ) *ts += 'A' - 'a';
176: ts++;
177: }
178: return( string );
179: }
180: /*
181: * Remove all backspaces, general canonical processesing
182: */
183: char *cannon( string )
184: char *string;
185: {
186: char *ts, *ts2;
187: /*
188: * Take out all backspaces
189: */
190: ts2 = ts = string;
191: while ( *ts != '\0' ) {
192: if ( *ts == '\b' ) {
193: if ( ts != string ) ts2--;
194: }
195: else {
196: if ( ts != ts2 ) *ts2 = *ts;
197: ts2++;
198: }
199: ts++;
200: }
201: if ( ts != ts2 ) *ts2 = '\0';
202: return( string );
203: }
204: /*
205: * Get the next token and treat it as a value for the previous
206: * token, such as the file name for a read
207: */
208: char *
209: collect()
210: {
211: static char buff[64];
212: char c;
213: int i;
214: while ( (c=input()) == ' ' || c == '\t' );
215: if ( c == '\n' ) {
216: unput( c );
217: return( 0 );
218: }
219: i = 1;
220: buff[0] = c;
221: while ( (c=input()) > ' ' ) buff[i++] = c;
222: buff[i] = '\0';
223: unput( c );
224: return( buff );
225: }
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