mirrors/ecl
1
Fork 0
mirror of https://gitlab.com/embeddable-common-lisp/ecl.git synced 2025-12-06 02:40:26 -08:00
Code Issues Projects Releases Packages Wiki Activity

streams: implement new interfaces for unreading and peeking bytes

Browse source 
ecl_file_ops has two new members:

  void (*unread_byte)(cl_object strm, cl_object byte);
  cl_object (*peek_byte)(cl_object strm);

C API additions:

  void ecl_unread_byte (cl_object byte, cl_object strm)
  cl_object ecl_peek_byte (cl_object strm)

  si_unread_byte(cl_object strm, cl_object byte)    [1]
  si_peek_byte(cl_object strm, cl_object byte)      [2]

Lisp API additions:

  (ext:unread-byte stream byte) :: integer          [1]
  (ext:peek-byte   stream byte) :: (or integer nil) [2]

  (gray:stream-unread-byte stream byte) :: null
  (gray:stream-peek-byte stream) :: (or integer :eof)

We implement a "generic" version of unread-byte by storing it in a new slot
last_byte.
This commit is contained in:
Daniel Kochmański 2025-07-22 14:47:53 +02:00
parent a887d040a2
commit a8e57c60a5
14 changed files with 247 additions and 10 deletions
Download patch file Download diff file Expand all files Collapse all files

13
src/c/streams/strm_sequence.d
View file

@ -46,6 +46,15 @@ seq_in_unread_char(cl_object strm, ecl_character c)
strm->stream.byte_stack = ECL_NIL;
}
static void
seq_in_unread_byte(cl_object strm, cl_object byte)
{
unlikely_if(SEQ_INPUT_POSITION(strm) <= 0) {
ecl_unread_error(strm);
}
SEQ_INPUT_POSITION(strm) -= 1;
}
#ifdef ecl_uint16_t
static ecl_character
seq_in_ucs2_read_char(cl_object strm)
@ -160,6 +169,8 @@ const struct ecl_file_ops seq_in_ops = {
ecl_generic_read_byte,
ecl_not_output_write_byte,
seq_in_unread_byte,
ecl_generic_peek_byte,
ecl_eformat_read_char,
ecl_not_output_write_char,
@ -370,6 +381,8 @@ const struct ecl_file_ops seq_out_ops = {
ecl_not_input_read_byte,
ecl_generic_write_byte,
ecl_not_input_unread_byte,
ecl_generic_peek_byte,
ecl_not_input_read_char,
ecl_eformat_write_char,