/* GetChar - get the next character */
int GetChar(ParseContext *c)
{
int ch;
/* check for being in a comment */
if (c->inComment) {
if (!SkipComment(c))
return EOF;
c->inComment = VMFALSE;
}
/* loop until we find a non-comment character */
for (;;) {
/* get the next character */
if ((ch = XGetC(c)) == EOF)
return EOF;
/* check for a comment */
else if (ch == '/') {
if ((ch = XGetC(c)) == '/') {
while ((ch = XGetC(c)) != EOF)
;
}
else if (ch == '*') {
if (!SkipComment(c)) {
c->inComment = VMTRUE;
return EOF;
}
}
else {
UngetC(c);
ch = '/';
break;
}
}
/* handle a normal character */
else
break;
}
/* return the character */
return ch;
}
/* CharToken - get a character constant */
static int CharToken(ParseContext *c)
{
int ch = LiteralChar(c);
if (XGetC(c) != '\'')
ParseError(c,"Expecting a closing single quote");
c->token[0] = ch;
c->token[1] = '\0';
c->value = ch;
return T_NUMBER;
}
/* SkipComment - skip characters up to the end of a comment */
static int SkipComment(ParseContext *c)
{
int lastch, ch;
lastch = '\0';
while ((ch = XGetC(c)) != EOF) {
if (lastch == '*' && ch == '/')
return VMTRUE;
lastch = ch;
}
return VMFALSE;
}
/* LiteralChar - get a character from a literal string */
static int LiteralChar(ParseContext *c)
{
int ch;
switch (ch = XGetC(c)) {
case 'n':
ch = '\n';
break;
case 'r':
ch = '\r';
break;
case 't':
ch = '\t';
break;
case EOF:
ch = '\\';
break;
}
return ch;
}
/* StringToken - get a string */
static int StringToken(ParseContext *c)
{
int ch,len;
char *p;
/* collect the string */
p = c->token; len = 0;
while ((ch = XGetC(c)) != EOF && ch != '"') {
if (++len > MAXTOKEN)
ParseError(c, "String too long");
*p++ = (ch == '\\' ? LiteralChar(c) : ch);
}
*p = '\0';
/* check for premature end of file */
if (ch != '"')
ParseError(c, "unterminated string");
/* return the token */
return T_STRING;
}