/*Used to determine what type is coming next in the stream
*Inputs:
* in - the stream to read from
* c - the first non-whitespace character to look at*/
object_type next_type(FILE *in, char c){
int next_char;
if(c == EOF){
printf("Got EOF, exiting\n");
exit(0);
}
if(c == '#'){ /*a boolean or character*/
next_char = peek(in);
switch(next_char){
case 't':
case 'f':
return BOOLEAN;
case '\\':
return CHARACTER;
default:
fprintf(stderr,
"Unknown boolean or character literal\n");
exit(1);
}
}else if (isdigit(c) || (c == '-' && isdigit(peek(in)))){
ungetc(c, in);
return FIXNUM;
}else if(c == '('){
if(peek(in) == ')'){
return EMPTY_LIST;
}else{
return PAIR;
}
}else if(c == '"'){
return STRING;
/*if this is the start of a symbol*/
}else if(is_symbol_start(c) ||
/*or +/- by themselves*/
((c == '+' || c == '-') && is_delimiter(peek(in)))){
//put this first character back
ungetc(c, in);
return SYMBOL;
}else{
fprintf(stderr, "Bad input. Unexpected '%c'\n", c);
exit(1);
}
fprintf(stderr, "No object type, no error... wtf?\n");
exit(1);
}
static void pgn_read_token(pgn_t * pgn) {
ASSERT(pgn!=NULL);
// skip white-space characters
pgn_skip_blanks(pgn);
// init
pgn->token_type = TOKEN_ERROR;
strcpy(pgn->token_string,"");
pgn->token_length = 0;
pgn->token_line = pgn->char_line;
pgn->token_column = pgn->char_column;
// determine token type
if (false) {
} else if (pgn->char_hack == CHAR_EOF) {
pgn->token_type = TOKEN_EOF;
} else if (strchr(".[]()<>",pgn->char_hack) != NULL) {
// single-character token
pgn->token_type = pgn->char_hack;
sprintf(pgn->token_string,"%c",pgn->char_hack);
pgn->token_length = 1;
} else if (pgn->char_hack == '*') {
pgn->token_type = TOKEN_RESULT;
sprintf(pgn->token_string,"%c",pgn->char_hack);
pgn->token_length = 1;
} else if (pgn->char_hack == '!') {
pgn_char_read(pgn);
if (false) {
} else if (pgn->char_hack == '!') { // "!!"
pgn->token_type = TOKEN_NAG;
strcpy(pgn->token_string,"3");
pgn->token_length = 1;
} else if (pgn->char_hack == '?') { // "!?"
pgn->token_type = TOKEN_NAG;
strcpy(pgn->token_string,"5");
pgn->token_length = 1;
} else { // "!"
pgn_char_unread(pgn);
pgn->token_type = TOKEN_NAG;
strcpy(pgn->token_string,"1");
pgn->token_length = 1;
}
} else if (pgn->char_hack == '?') {
pgn_char_read(pgn);
if (false) {
} else if (pgn->char_hack == '?') { // "??"
pgn->token_type = TOKEN_NAG;
strcpy(pgn->token_string,"4");
pgn->token_length = 1;
} else if (pgn->char_hack == '!') { // "?!"
pgn->token_type = TOKEN_NAG;
strcpy(pgn->token_string,"6");
pgn->token_length = 1;
} else { // "?"
pgn_char_unread(pgn);
pgn->token_type = TOKEN_NAG;
strcpy(pgn->token_string,"2");
pgn->token_length = 1;
}
} else if (is_symbol_start(pgn->char_hack)) {
// symbol, integer, or result
pgn->token_type = TOKEN_INTEGER;
pgn->token_length = 0;
do {
if (pgn->token_length >= PGN_STRING_SIZE-1) {
my_fatal("pgn_read_token(): symbol too long at line %d, column %d\n",pgn->char_line,pgn->char_column);
}
if (!isdigit(pgn->char_hack)) pgn->token_type = TOKEN_SYMBOL;
pgn->token_string[pgn->token_length++] = pgn->char_hack;
pgn_char_read(pgn);
} while (is_symbol_next(pgn->char_hack));
pgn_char_unread(pgn);
ASSERT(pgn->token_length>0&&pgn->token_length<PGN_STRING_SIZE);
pgn->token_string[pgn->token_length] = '\0';
if (my_string_equal(pgn->token_string,"1-0")
|| my_string_equal(pgn->token_string,"0-1")
|| my_string_equal(pgn->token_string,"1/2-1/2")) {
pgn->token_type = TOKEN_RESULT;
}
} else if (pgn->char_hack == '"') {
// string
pgn->token_type = TOKEN_STRING;
pgn->token_length = 0;
while (true) {
pgn_char_read(pgn);
if (pgn->char_hack == CHAR_EOF) {
my_fatal("pgn_read_token(): EOF in string at line %d, column %d\n",pgn->char_line,pgn->char_column);
}
if (pgn->char_hack == '"') break;
if (pgn->char_hack == '\\') {
pgn_char_read(pgn);
if (pgn->char_hack == CHAR_EOF) {
my_fatal("pgn_read_token(): EOF in string at line %d, column %d\n",pgn->char_line,pgn->char_column);
}
if (pgn->char_hack != '"' && pgn->char_hack != '\\') {
// bad escape, ignore
if (pgn->token_length >= PGN_STRING_SIZE-1) {
my_fatal("pgn_read_token(): string too long at line %d, column %d\n",pgn->char_line,pgn->char_column);
}
pgn->token_string[pgn->token_length++] = '\\';
}
}
if (pgn->token_length >= PGN_STRING_SIZE-1) {
my_fatal("pgn_read_token(): string too long at line %d, column %d\n",pgn->char_line,pgn->char_column);
}
pgn->token_string[pgn->token_length++] = pgn->char_hack;
}
ASSERT(pgn->token_length>=0&&pgn->token_length<PGN_STRING_SIZE);
pgn->token_string[pgn->token_length] = '\0';
} else if (pgn->char_hack == '$') {
// NAG
pgn->token_type = TOKEN_NAG;
pgn->token_length = 0;
while (true) {
pgn_char_read(pgn);
if (!isdigit(pgn->char_hack)) break;
if (pgn->token_length >= 3) {
my_fatal("pgn_read_token(): NAG too long at line %d, column %d\n",pgn->char_line,pgn->char_column);
}
pgn->token_string[pgn->token_length++] = pgn->char_hack;
}
pgn_char_unread(pgn);
if (pgn->token_length == 0) {
my_fatal("pgn_read_token(): malformed NAG at line %d, column %d\n",pgn->char_line,pgn->char_column);
}
ASSERT(pgn->token_length>0&&pgn->token_length<=3);
pgn->token_string[pgn->token_length] = '\0';
} else {
// unknown token
// my_fatal("lexical error at line %d, column %d\n",pgn->char_line,pgn->char_column);
}
}