Initial commit

Utf16.c

@@ -0,0 +1,64 @@
+#include "CgeStr.h"
+
+#define INVALID_RUNE    0xFFFD
+
+int CgeUtf16Encode(uint32_t rune, uint16_t* data) {
+    if (rune <= 0xFFFF) {
+        if (rune >= 0xD800 && rune <= 0xDFFF)
+            return -1;
+        data[0] = (uint16_t)rune;
+        return 1;
+    }
+    if (rune <= 0x10FFFF) {
+        uint32_t x = rune - 0x10000;
+        data[0] = (uint16_t)(0xD800 + (x >> 10));
+        data[1] = (uint16_t)(0xDC00 + (x & 0x3FF));
+        return 2;
+    }
+    return -1;
+}
+
+int CgeUtf16EncodeLax(uint32_t rune, uint16_t* data) {
+    int result;
+
+    result = CgeUtf16Encode(rune, data);
+    if (result == -1)
+        result = CgeUtf16Encode(INVALID_RUNE, data);
+
+    return result;
+}
+
+int CgeUtf16Decode(const uint16_t* data, size_t size, uint32_t* rune) {
+    uint16_t trail, lead = data[0];
+
+    if (size == 0)
+        return -1;
+
+    if (lead < 0xD800 || lead > 0xDFFF) {
+        *rune = lead;
+        return 1;
+    } else if (lead >= 0xD800 && lead <= 0xDBFF) {
+        if (size < 2)
+            return -1;
+
+        trail = data[1];
+        if (trail >= 0xDC00 && trail <= 0xDFFF) {
+            *rune = 0x10000 + ((lead & 0x3FF) << 10) + (trail & 0x3FF);
+            return 2;
+        }
+    }
+
+    return -1;
+}
+
+int CgeUtf16DecodeLax(const uint16_t* data, size_t size, uint32_t* rune) {
+    int result;
+
+    result = CgeUtf16Decode(data, size, rune);
+    if (result == -1) {
+        *rune = INVALID_RUNE;
+        result = 1;
+    }
+
+    return result;
+}