collapseos/tools/stripfc.c
2020-04-25 16:02:47 -04:00

58 lines
1.6 KiB
C

#include <stdio.h>
/* read stdin and strip Forth-style comments before spitting in stdout. This
also deduplicate spaces and newlines.
THIS PARSING IS IMPERFECT. Only a Forth interpreter can reliably detect
comments. For example, a naive parser misinterprets the "(" word definition as
a comment.
We work around this by considering as a comment opener only "(" chars preceeded
by more than once space or by a newline. Hackish, but works.
*/
int main()
{
int spccnt = 1; // if the first char is a (, consider it a comment opener.
int incomment = 0;
int c;
c = getchar();
while ( c != EOF ) {
if (c == '\n') {
if (!incomment) {
// We still spit newlines whenever we see them, Forth interpreter
// doesn't like when they're not there...
putchar(c);
}
spccnt += 1;
} else if (c == ' ') {
spccnt++;
} else {
if (incomment) {
if ((c == ')') && spccnt) {
incomment = 0;
}
} else {
if ((c == '(') && spccnt) {
putchar(' ');
spccnt = 0;
int next = getchar();
if (next <= ' ') {
incomment = 1;
continue;
}
putchar(c);
c = next;
}
if (spccnt) {
putchar(' ');
}
putchar(c);
}
spccnt = 0;
}
c = getchar();
}
return 0;
}