From 4b8c53c088e393147a77e56bb76f6f997be043ed Mon Sep 17 00:00:00 2001
From: Justin Ethier <justin.ethier@gmail.com>
Date: Mon, 18 Dec 2017 17:27:53 -0500
Subject: [PATCH] Issue #236 - Added C functions for single-byte I/O

---
 include/cyclone/runtime.h |  3 ++
 runtime.c                 | 58 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+)

diff --git a/include/cyclone/runtime.h b/include/cyclone/runtime.h
index 80ea3f87..d2b89ee3 100644
--- a/include/cyclone/runtime.h
+++ b/include/cyclone/runtime.h
@@ -267,6 +267,9 @@ object Cyc_io_close_output_port(void *data, object port);
 object Cyc_io_flush_output_port(void *data, object port);
 object Cyc_io_read_char(void *data, object cont, object port);
 object Cyc_io_peek_char(void *data, object cont, object port);
+object Cyc_write_u8(void *data, object c, object port);
+object Cyc_io_read_u8(void *data, object cont, object port);
+object Cyc_io_peek_u8(void *data, object cont, object port);
 object Cyc_io_read_line(void *data, object cont, object port);
 void Cyc_io_read_token(void *data, object cont, object port);
 /**@}*/
diff --git a/runtime.c b/runtime.c
index a163cd87..7df4729c 100644
--- a/runtime.c
+++ b/runtime.c
@@ -1113,6 +1113,21 @@ object Cyc_write_char(void *data, object c, object port)
   return quote_void;
 }
 
+object Cyc_write_u8(void *data, object c, object port)
+{
+  Cyc_check_port(data, port);
+  if (obj_is_char(c)) {
+    FILE *fp = ((port_type *) port)->fp;
+    if (fp){
+      char_type unbox = obj_obj2char(c);
+      fprintf(fp, "%c", unbox);
+    }
+  } else {
+    Cyc_rt_raise2(data, "Argument is not a character", c);
+  }
+  return quote_void;
+}
+
 /* Fast versions of member and assoc */
 object memberp(void *data, object x, list l)
 {
@@ -6401,6 +6416,29 @@ object Cyc_io_peek_char(void *data, object cont, object port)
   return Cyc_EOF;
 }
 
+object Cyc_io_peek_u8(void *data, object cont, object port)
+{
+  FILE *stream;
+  port_type *p;
+  int c;
+
+  Cyc_check_port(data, port);
+  {
+    p = (port_type *)port;
+    stream = ((port_type *) port)->fp;
+    if (stream == NULL) {
+      Cyc_rt_raise2(data, "Unable to read from closed port: ", port);
+    }
+    set_thread_blocked(data, cont);
+    if (p->mem_buf_len == 0 || p->mem_buf_len == p->buf_idx) {
+      _read_next_char(data, cont, p);
+    }
+    c = p->mem_buf[p->buf_idx];
+    return_thread_runnable(data, (c != EOF) ? obj_char2obj(c) : Cyc_EOF);
+  }
+  return Cyc_EOF;
+}
+
 // TODO: full requirements are:
 //
 // Returns #t if a character is ready on the textual input
@@ -6442,6 +6480,26 @@ object Cyc_io_read_char(void *data, object cont, object port)
   return Cyc_EOF;
 }
 
+object Cyc_io_read_u8(void *data, object cont, object port)
+{
+  port_type *p = (port_type *)port;
+  Cyc_check_port(data, port);
+  if (p->fp == NULL) {
+    Cyc_rt_raise2(data, "Unable to read from closed port: ", port);
+  }
+  {
+    char_type codepoint;
+    int c;
+    set_thread_blocked(data, cont);
+    _read_next_char(data, cont, p);
+    c = p->mem_buf[p->buf_idx++];
+    codepoint = (char_type) c;
+    p->col_num++;
+    return_thread_runnable(data, (c != EOF) ? obj_char2obj(codepoint) : Cyc_EOF);
+  }
+  return Cyc_EOF;
+}
+
 /* TODO: this function needs some work, but approximates what is needed */
 object Cyc_io_read_line(void *data, object cont, object port)
 {