int reader_skipline ( struct reader *r ) {
int k = 0;
/* Check inputs. */
if ( r == NULL )
return error(r,reader_err_null);
/* Has an EOF already been reached? */
if ( r->flags & reader_flag_eof )
return error(r,reader_err_eof);
/* Skip any input util a comment_start is hit. */
while ( r->c != EOF && r->c != '\n' && r->c != '\r' ) {
/* Get the next char. */
k += 1;
reader_getc( r );
}
/* Skip the newline character. */
reader_getc( r );
/* Return the number of read characters. */
return k;
}
/* Consume remaining whitespace on line, including linefeed. */
static void consume_whitespace (reader_t * r)
{
int c = reader_getc (r);
while (strchr (" \t\r", c) != NULL)
c = reader_getc (r);
if (c != '\n')
reader_putc (r, c);
}
/* Consume remaining characters on line, including linefeed. */
static void consume_line (reader_t * r)
{
int c = reader_getc (r);
while (c != '\n' && c != EOF)
c = reader_getc (r);
if (c != '\n')
reader_putc (r, c);
}
int reader_getcomment ( struct reader *r , char *buff , int buff_size ) {
int k = 0;
/* Check inputs. */
if ( r == NULL || buff == NULL )
return error(r,reader_err_null);
/* Has an EOF already been reached? */
if ( r->flags & reader_flag_eof )
return error(r,reader_err_eof);
/* Skip any input util a comment_start is hit. */
while ( !reader_iscomm_start( r , r->c ) )
if ( reader_getc( r ) == EOF )
return error(r,reader_err_eof);
/* Skip the comment start character. */
if ( reader_getc( r ) == EOF ) {
buff[0] = 0;
return 0;
}
/* Write the input to the buffer until a comm_stop is reached. */
while ( r->c != EOF && !reader_iscomm_stop( r , r->c ) ) {
/* Check buffer length. */
if ( k < buff_size-1 ) {
/* Store the current char to the buff. */
buff[k] = r->c;
k += 1;
/* Get the next char. */
reader_getc( r );
}
else
return error(r,reader_err_buff);
} /* Read comment into buffer. */
/* Terminate the comment. */
buff[k] = 0;
/* Read the next char. */
reader_getc( r );
/* Return the comment length. */
return k;
}
int reader_skiptoken ( struct reader *r ) {
int k = 0;
/* Check inputs. */
if ( r == NULL )
return error(r,reader_err_null);
/* Has an EOF already been reached? */
if ( r->flags & reader_flag_eof )
return error(r,reader_err_eof);
/* Skim-off whitespace and/or comments. */
while ( 1 ) {
/* Skip whitespace. */
if ( reader_isws( r , r->c ) ) {
if ( reader_getc( r ) == EOF )
return error(r,reader_err_eof);
}
/* Skip comments. */
else if ( reader_iscomm_start( r , r->c ) ) {
do {
if ( reader_getc( r ) == EOF )
return error(r,reader_err_eof);
} while ( !reader_iscomm_stop( r , r->c ) );
if ( reader_getc( r ) == EOF )
return error(r,reader_err_eof);
}
else
break;
} /* get ws and comments. */
/* Read the token. */
while ( r->c != EOF && !reader_isws( r , r->c ) && !reader_iscomm_start( r , r->c ) ) {
/* Get the next char. */
k += 1;
reader_getc( r );
} /* Read the token. */
/* Return the token length. */
return k;
}
int reader_getline ( struct reader *r , char *buff , int buff_size ) {
int k = 0;
/* Check inputs. */
if ( r == NULL || buff == NULL )
return error(r,reader_err_null);
/* Has an EOF already been reached? */
if ( r->flags & reader_flag_eof )
return error(r,reader_err_eof);
/* Skip any input util a comment_start is hit. */
while ( r->c != EOF && r->c != '\n' && r->c != '\r' ) {
/* Is there room in the buffer? */
if ( k < buff_size-1 ) {
/* Store this character. */
buff[k] = r->c;
k += 1;
/* Get the next char. */
reader_getc( r );
}
/* Otherwise, buffer full. */
else
return error(r,reader_err_buff);
}
/* Skip the newline character. */
reader_getc( r );
/* Terminate the buffer. */
buff[k] = 0;
/* Return the number of read characters. */
return k;
}
int reader_skipcomment ( struct reader *r ) {
int k = 0;
/* Check inputs. */
if ( r == NULL )
return error(r,reader_err_null);
/* Has an EOF already been reached? */
if ( r->flags & reader_flag_eof )
return error(r,reader_err_eof);
/* Skip any input util a comment_start is hit. */
while ( !reader_iscomm_start( r , r->c ) )
if ( reader_getc( r ) == EOF )
return error(r,reader_err_eof);
/* Skip the comment start character. */
if ( reader_getc( r ) == EOF )
return 0;
/* Read the input until a comm_stop is reached. */
while ( r->c != EOF && !reader_iscomm_stop( r , r->c ) ) {
/* Get the next char. */
k += 1;
reader_getc( r );
} /* Read comment into buffer. */
/* Read the next char. */
reader_getc( r );
/* Return the comment length. */
return k;
}
/* Load into buffer until character, ignoring escaped ones. */
static int buf_read (reader_t * r, char *halt)
{
int esc = 0;
int c = reader_getc (r);
esc = 0;
if (c == '\\')
{
c = reader_getc (r);
esc = 1;
}
while ((esc || strchr (halt, c) == NULL) && (c != EOF))
{
buf_append (r, c);
c = reader_getc (r);
esc = 0;
if (c == '\\')
{
c = reader_getc (r);
esc = 1;
}
}
reader_putc (r, c);
return !esc;
}
/* Read a single sexp from the reader. */
object_t *read_sexp (reader_t * r)
{
/* Check for a shebang line. */
if (r->shebang == -1)
{
char str[2];
str[0] = reader_getc (r);
str[1] = reader_getc (r);
if (str[0] == '#' && str[1] == '!')
{
/* Looks like a she-bang line. */
r->shebang = 1;
consume_line (r);
}
else
{
r->shebang = 0;
reader_putc (r, str[1]);
reader_putc (r, str[0]);
}
}
r->done = 0;
r->error = 0;
push (r);
print_prompt (r);
while (!r->eof && !r->error && (list_empty (r) || stack_height (r) > 1))
{
int nc, c = reader_getc (r);
switch (c)
{
case EOF:
r->eof = 1;
break;
/* Comments */
case ';':
consume_line (r);
break;
/* Dotted pair */
case '.':
nc = reader_getc (r);
if (strchr (" \t\r\n()", nc) != NULL)
{
if (r->state->dotpair_mode > 0)
read_error (r, "invalid dotted pair syntax");
else if (r->state->vector_mode > 0)
read_error (r, "dotted pair not allowed in vector");
else
{
r->state->dotpair_mode = 1;
reader_putc (r, nc);
}
}
else
{
/* Turn it into a decimal point. */
reader_putc (r, nc);
reader_putc (r, '.');
reader_putc (r, '0');
}
break;
/* Whitespace */
case '\n':
r->linecnt++;
print_prompt (r);
case ' ':
case '\t':
case '\r':
break;
/* Parenthesis */
case '(':
push (r);
break;
case ')':
if (r->state->quote_mode)
read_error (r, "unbalanced parenthesis");
else if (r->state->vector_mode)
read_error (r, "unbalanced brackets");
else
addpop (r);
break;
/* Vectors */
case '[':
push (r);
r->state->vector_mode = 1;
break;
case ']':
if (r->state->quote_mode)
read_error (r, "unbalanced parenthesis");
else if (!r->state->vector_mode)
read_error (r, "unbalanced brackets");
else
addpop (r);
break;
/* Quoting */
case '\'':
push (r);
add (r, quote);
if (!r->error)
r->state->quote_mode = 1;
break;
/* strings */
case '"':
buf_read (r, "\"");
add (r, parse_str (r));
reader_getc (r); /* Throw away other quote. */
break;
/* numbers and symbols */
default:
buf_append (r, c);
buf_read (r, " \t\r\n()[];");
object_t *o = parse_atom (r);
if (!r->error)
add (r, o);
break;
}
}
if (!r->eof && !r->error)
consume_whitespace (r);
if (r->error)
return err_symbol;
/* Check state */
r->done = 1;
if (stack_height (r) > 1 || r->state->quote_mode
|| r->state->dotpair_mode == 1)
{
read_error (r, "premature end of file");
return err_symbol;
}
if (list_empty (r))
{
obj_destroy (pop (r));
return NIL;
}
object_t *wrap = pop (r);
object_t *sexp = UPREF (CAR (wrap));
obj_destroy (wrap);
return sexp;
}
int reader_init ( struct reader *r , int fd , char *ws , char *comm_start , char *comm_stop , int buffsize ) {
/* Check inputs. */
if ( r == NULL )
return error(r,reader_err_null);
/* Init the flags. */
r->flags = reader_flag_none;
/* Set the file. */
r->fd = fd;
/* Init the buffer. */
if ( ( r->buff = (char *)malloc( buffsize ) ) == NULL )
return error(r,reader_err_malloc);
r->first = 0;
r->last = 0;
r->size = buffsize;
/* Re-set the line and column counts. */
r->line = 1;
r->col = 0;
/* Read the first character. */
if ( reader_getc( r ) == EOF )
r->flags = reader_flag_eof;
else
r->flags |= reader_flag_ready;
/* Did the user supply whitespace? */
if ( ws != NULL ) {
r->ws = ws;
for ( r->nr_ws = 0 ; ws[r->nr_ws] != 0 ; r->nr_ws++ );
}
else {
r->ws = " \f\n\r\t\v";
r->nr_ws = 6;
}
/* Did the user supply comment start/stop? */
if ( comm_start != NULL ) {
r->comm_start = comm_start;
for ( r->nr_comm_start = 0 ; comm_start[r->nr_comm_start] != 0 ; r->nr_comm_start++ );
}
else {
r->comm_start = "";
r->nr_comm_start = 0;
}
if ( comm_stop != NULL ) {
r->comm_stop = comm_stop;
for ( r->nr_comm_stop = 0 ; comm_stop[r->nr_comm_stop] != 0 ; r->nr_comm_stop++ );
}
else {
r->comm_stop = "\n\r";
r->nr_comm_stop = 2;
}
/* We're all set. */
return reader_err_ok;
}
int reader_gettoken ( struct reader *r , char *buff , int buff_size ) {
int k = 0;
/* Check inputs. */
if ( r == NULL || buff == NULL )
return error(r,reader_err_null);
/* Has an EOF already been reached? */
if ( r->flags & reader_flag_eof )
return error(r,reader_err_eof);
/* Skim-off whitespace and/or comments. */
while ( 1 ) {
/* Skip whitespace. */
if ( reader_isws( r , r->c ) ) {
if ( reader_getc( r ) == EOF )
return error(r,reader_err_eof);
}
/* Skip comments. */
else if ( reader_iscomm_start( r , r->c ) ) {
do {
if ( reader_getc( r ) == EOF )
return error(r,reader_err_eof);
} while ( !reader_iscomm_stop( r , r->c ) );
if ( reader_getc( r ) == EOF )
return error(r,reader_err_eof);
}
else
break;
} /* get ws and comments. */
/* Read the token. */
while ( r->c != EOF && !reader_isws( r , r->c ) && !reader_iscomm_start( r , r->c ) ) {
/* Check buffer length. */
if ( k < buff_size-1 ) {
/* Store the current char to the buff. */
buff[k] = r->c;
k += 1;
/* Get the next char. */
reader_getc( r );
}
else
return error(r,reader_err_buff);
} /* Read the token. */
/* Terminate the token. */
buff[k] = 0;
/* Return the token length. */
return k;
}
