Implement streams IPC mechanism

ce/edit.c

@@ -14,6 +14,7 @@
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
+#include <streams.h>
 #include <string.h>
 #include <system.h>
 #include <tcursor.h>
@@ -231,10 +232,15 @@ void edit_start (const char* volume, const char* file_path, const char* text, si
         (int)(editor.cursor.line - editor.row_offset) + 1,
         (int)(editor.cursor.col - editor.col_offset) + 1 + (int)gutter_width);
 
-    mail_send (process_get_exec_pgid (), backbuffer, bbptr - backbuffer);
+    stream_write (process_get_pgid (), STREAM_OUT, backbuffer, bbptr - backbuffer);
 
     uint8_t ch = 0;
-    mail_receive (&ch, 1);
+    for (;;) {
+      if (stream_read (process_get_pgid (), STREAM_IN, &ch, 1) > 0)
+        break;
+      else
+        sched ();
+    }
 
     switch (ch) {
     case '\b':