// Parse a character constant of the form 'c'
void chrconst(void) {
fetchc();
symval = inchar;
sym = s_nval;
fetchc();
if (inchar != '\'') expectedchar('\'');
fetchc(); // consume "
}
// Comment: Skip from // to end of line, return next symbol
void skipcomment(void) {
while (sym == s_comment) {
while (inchar && (inchar != '\n') && (inchar != '\r')) fetchc();
if (!inchar) {
sym = s_eof;
return;
}
else {
fetchc(); // eat \r or \n
getsym(); // and tee up what's next
}
}
}
// Parse an identifier from the input stream
void parseid(void) {
char c = *idbuf = tolower(inchar);
byte idbuflen = 1;
fetchc();
while (isalnum(inchar) || (inchar == '.') || (inchar == '_')) {
if (idbuflen >= IDLEN) overflow(M_id);
idbuf[idbuflen++] = tolower(inchar);
fetchc();
}
idbuf[idbuflen] = 0;
// do we have a one-char alpha nvar identifier?
if ((idbuflen == 1) && isalpha(c)) {
sym = s_nvar;
symval = c - 'a';
}
// a pin identifier 'a'digit* or 'd'digit*?
else if ((idbuflen <= 3) &&
((c == 'a') || (c == 'd')) &&
isdigit(idbuf[1]) && (
#if !defined(TINY85)
isdigit(idbuf[2]) ||
#endif
(idbuf[2] == 0))) {
sym = (c == 'a') ? s_apin : s_dpin;
symval = pinnum(idbuf);
}
// reserved word?
else if (findindex(idbuf, (const prog_char *) reservedwords, 1)) {
sym = pgm_read_byte(reservedwordtypes + symval); // e.g., s_if or s_while
}
// function?
else if (findindex(idbuf, (const prog_char *) functiondict, 1)) sym = s_nfunct;
#ifdef LONG_ALIASES
else if (findindex(idbuf, (const prog_char *) aliasdict, 0)) sym = s_nfunct;
#endif
#ifdef PIN_ALIASES
else if (findpinname(idbuf)) {;} // sym and symval are set in findpinname
#endif
#ifdef USER_FUNCTIONS
else if (find_user_function(idbuf)) sym = s_nfunct;
#endif
else findscript(idbuf);
}
// Parse a numeric constant from the input stream
void parsenum(void) {
byte radix;
radix = 10;
symval = inchar - '0';
for (;;) {
fetchc();
inchar = tolower(inchar);
if ((radix == 10) && (symval == 0)) {
if (inchar == 'x') { radix = 16; continue; }
else if (inchar == 'b') { radix = 2; continue; }
}
if (isdigit(inchar)) {
inchar = inchar - '0';
if (inchar >= radix) break;
symval = (symval*radix) + inchar;
}
else if (radix == 16) {
if ((inchar >= 'a') && (inchar <= 'f'))
symval = (symval*radix) + inchar - 'a' + 10;
else break;
}
else break;
}
sym = s_nval;
}
int gethex(byte count) {
int value = 0;
while (count--) {
value = (value << 4) + hexval(inchar);
fetchc();
}
return value;
}
// Parse a "quoted string" from the input.
//
// Enter with sym = s_quote therefore inchar = first char in string
// Exit with inchar = first char past closing s_quote
//
// Callers will need to call getsym() to resume parsing
//
void parsestring(void (*charFunc)(char)) {
for (;;) {
if (inchar == ASC_QUOTE) { // found the string terminator
fetchc(); // consume it so's we move along
break; // done with the big loop
}
else if (inchar == ASC_BKSLASH) { // bkslash escape conventions per K&R C
fetchc();
switch (inchar) {
// pass-thrus
case ASC_QUOTE: break; // just a dbl quote, move along
case ASC_BKSLASH: break; // just a backslash, move along
// minor translations
case 'n': inchar = '\n'; break;
case 't': inchar = '\t'; break;
case 'r': inchar = '\r'; break;
case 'x': // bkslash x hexdigit hexdigit
fetchc();
if (ishex(inchar)) {
byte firstnibble = hexval(inchar);
fetchc();
if (ishex(inchar)) {
inchar = hexval(inchar) + (firstnibble << 4);
break;
}
}
unexpected(M_char);
inchar = 'x';
break;
}
}
// Process the character we just extracted
(*charFunc)(inchar);
fetchc();
if (!inchar) unexpected(M_eof); // get next else end of input before string terminator
}
}
// Parse a one- or two-char operator like >, >=, >>, ...
void parseop(void) {
sym = inchar; // think horse not zebra
fetchc(); // inchar has second char of token or ??
const prog_char *tk = twochartokens;
byte index = 0;
for (;;) {
byte c1 = pgm_read_byte(tk++);
if (!c1) return;
byte c2 = pgm_read_byte(tk++);
if ((sym == c1) && (inchar == c2)) {
sym = (byte) pgm_read_byte(twocharsyms + index);
fetchc();
if (sym == s_comment) skipcomment();
return;
}
index++;
}
}
/////////
//
// "cat": copy file to serial out
//
numvar sdcat(void) {
if (!scriptfileexists((char *) getarg(1))) return 0;
numvar fetchmark = markparsepoint();
initparsepoint(SCRIPT_FILE, 0L, (char *) getarg(1));
while (inchar) {
if (inchar == '\n') spb('\r');
spb(inchar);
fetchc();
}
returntoparsepoint(fetchmark, 1);
return 1;
}
// One-char literal symbols, like '*' and '+'.
void litsym(void) {
sym = inchar;
fetchc();
}
// Skip to next nonblank and return the symbol therefrom
void skpwhite(void) {
while (chartype(inchar) == 0) fetchc();
getsym();
}
