[RELEASE] u22-v03

This version is submitted to U22 breau.

util/conv/CMakeLists.txt

@@ -0,0 +1,3 @@
+add_library(conv
+  charcode.c
+)

util/conv/charcode.c

@@ -0,0 +1,36 @@
+#include "./charcode.h"
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+
+size_t conv_charcode_utf8_to_utf32(uint32_t* c, const char* s, size_t len) {
+  assert(c != NULL);
+  assert(s != NULL);
+
+  if ((*s & 0x80) == 0x00) {
+    if (len < 1) return 0;
+    *c = s[0];
+    return 1;
+  }
+  if ((*s & 0xE0) == 0xC0) {
+    if (len < 2) return 0;
+    *c = (s[0] & 0x1F) << 6 | (s[1] & 0x3F);
+    return 2;
+  }
+  if ((*s & 0xF0) == 0xE0) {
+    if (len < 3) return 0;
+    *c = (s[0] & 0x0F) << 12 | (s[1] & 0x3F) << 6 | (s[2] & 0x3F);
+    return 3;
+  }
+  if ((*s & 0xF8) == 0xF0) {
+    if (len < 4) return 0;
+    *c =
+        (s[0] & 0x07) << 18 |
+        (s[1] & 0x3F) << 12 |
+        (s[2] & 0x3F) <<  6 |
+        (s[3] & 0x3F);
+    return 4;
+  }
+  return 0;
+}

util/conv/charcode.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <stddef.h>
+#include <stdint.h>
+
+size_t
+conv_charcode_utf8_to_utf32(
+    uint32_t*   c,
+    const char* s,
+    size_t      len
+);