/*
* Fills a table of paths to characters in the tree.
* Takes in a pointer to a huffmantree and a pointer to character pointers.
*/
void fill(huffmantree* tree, char** array){
int slot_size=((tree->size-1)/2+1)*sizeof(char); //maximum length of a path from root to leaf
char* path=malloc(slot_size);
path[0]=0;
filltable(tree, array, path);
free(path);
}
/*
* Helper method of fill.
* It assigns a string that represents the path to the character in the huffmantree
* to the corresponding slot in the table, an array of strings.
* Takes in a pointer to a huffmantree, a pointer to character pointers, which is the
* table, and a character array, which is the collector in the tail recursion.
*/
void filltable(huffmantree* tree, char** array, char* path){
if (huffmantree_isleaf(tree)){
int c=tree->c;
memcpy(array[c],path,strlen(path)+1);
}
else{
char* left_path=mystrdup(path,strlen(path)+2);
char* right_path=mystrdup(path, strlen(path)+2);
strcat(left_path,"0");
strcat(right_path, "1");
filltable(tree->left, array, left_path);
filltable(tree->right, array, right_path);
free(left_path);
free(right_path);
}
}
main() {
char c;
char d;
int sign;
int i;
char buf[80];
int pos;
static char digit[] = "0123456789";
/* Create output files */
if ((cfile = fopen("syntax.c", "w")) == NULL) {
perror("syntax.c");
exit(2);
}
if ((hfile = fopen("syntax.h", "w")) == NULL) {
perror("syntax.h");
exit(2);
}
fputs(writer, hfile);
fputs(writer, cfile);
/* Determine the characteristics of chars. */
c = -1;
if (c < 0)
sign = 1;
else
sign = 0;
for (nbits = 1 ; ; nbits++) {
d = (1 << nbits) - 1;
if (d == c)
break;
}
printf("%s %d bit chars\n", sign? "signed" : "unsigned", nbits);
if (nbits > 9) {
fputs("Characters can't have more than 9 bits\n", stderr);
exit(2);
}
size = (1 << nbits) + 1;
base = 1;
if (sign)
base += 1 << (nbits - 1);
digit_contig = 1;
for (i = 0 ; i < 10 ; i++) {
if (digit[i] != '0' + i)
digit_contig = 0;
}
/* Generate the #define statements in the header file */
fputs("/* Syntax classes */\n", hfile);
for (i = 0 ; synclass[i].name ; i++) {
sprintf(buf, "#define %s %d", synclass[i].name, i);
fputs(buf, hfile);
for (pos = strlen(buf) ; pos < 32 ; pos = pos + 8 &~ 07)
putc('\t', hfile);
fprintf(hfile, "/* %s */\n", synclass[i].comment);
}
putc('\n', hfile);
fputs("/* Syntax classes for is_ functions */\n", hfile);
for (i = 0 ; is_entry[i].name ; i++) {
sprintf(buf, "#define %s %#o", is_entry[i].name, 1 << i);
fputs(buf, hfile);
for (pos = strlen(buf) ; pos < 32 ; pos = pos + 8 &~ 07)
putc('\t', hfile);
fprintf(hfile, "/* %s */\n", is_entry[i].comment);
}
putc('\n', hfile);
fprintf(hfile, "#define SYNBASE %d\n", base);
fprintf(hfile, "#define PEOF %d\n\n", -base);
putc('\n', hfile);
fputs("#define BASESYNTAX (basesyntax + SYNBASE)\n", hfile);
fputs("#define DQSYNTAX (dqsyntax + SYNBASE)\n", hfile);
fputs("#define SQSYNTAX (sqsyntax + SYNBASE)\n", hfile);
putc('\n', hfile);
output_type_macros(); /* is_digit, etc. */
putc('\n', hfile);
/* Generate the syntax tables. */
fputs("#include \"shell.h\"\n", cfile);
fputs("#include \"syntax.h\"\n\n", cfile);
init();
fputs("/* syntax table used when not in quotes */\n", cfile);
add("\n", "CNL");
add("\\", "CBACK");
add("'", "CSQUOTE");
add("\"", "CDQUOTE");
add("`", "CBQUOTE");
add("$", "CVAR");
add("}", "CENDVAR");
add("<>();&| \t", "CSPCL");
print("basesyntax");
init();
fputs("\n/* syntax table used when in double quotes */\n", cfile);
add("\n", "CNL");
add("\\", "CBACK");
add("\"", "CENDQUOTE");
add("`", "CBQUOTE");
add("$", "CVAR");
add("}", "CENDVAR");
add("!*?[=", "CCTL");
print("dqsyntax");
init();
fputs("\n/* syntax table used when in single quotes */\n", cfile);
add("\n", "CNL");
add("'", "CENDQUOTE");
add("!*?[=", "CCTL");
print("sqsyntax");
filltable("0");
fputs("\n/* character classification table */\n", cfile);
add("0123456789", "ISDIGIT");
add("abcdefghijklmnopqrstucvwxyz", "ISLOWER");
add("ABCDEFGHIJKLMNOPQRSTUCVWXYZ", "ISUPPER");
add("_", "ISUNDER");
add("#?$!-*@", "ISSPECL");
print("is_type");
if (! digit_contig)
digit_convert();
exit(0);
}
