some progress

Common/bin.h

@@ -0,0 +1,45 @@
+/*
+    Generic interface for binary data parsing.
+*/
+
+#ifndef COM_BIN_H
+#define COM_BIN_H
+
+#include <stdint.h>
+
+#include "buf.h"
+
+#define COM_BIN_LIT_ENDIAN (1 << 0)
+#define COM_BIN_BIG_ENDIAN (1 << 1)
+#define COM_BIN_NAT_ENDIAN (1 << 2)
+
+typedef struct com_bin_interface {
+  /* Attempts to read exactly N bytes, returns false if it cannot. */
+  bool (*readn)(void *ctx, char *into, uint32_t bytes);
+  bool (*skipn)(void *ctx, uint32_t bytes);
+} com_bin_interface;
+
+typedef struct com_bin {
+  struct com_bin_interface interface;
+  void *ctx;
+  uint32_t flags;
+} com_bin;
+
+bool com_bin_read_i16(com_bin *b, int16_t *value);
+bool com_bin_read_u16(com_bin *b, uint16_t *value);
+/*
+  Read untyped bytes appending them to buffer.
+  NOTE: Buffer must have typesz of 1. */
+bool com_bin_read_bufb(com_bin *b, struct com_buf *buf, uint32_t bytes);
+/*
+  Inline byte buffer read, making a new buffer inside.
+  Resulted index can be safely used in case of future reallocations.
+  NOTE: Buffer must have typesz of 1. */
+bool com_bin_read_bufbi(com_bin *b, struct com_buf *buf, uint32_t *index,
+                        uint32_t bytes);
+
+/* TODO: Typed variant, use buf for typesz? */
+/* Skip N bytes. */
+bool com_bin_skip(com_bin *b, uint32_t n);
+
+#endif