Initial commit

Utf8.c

@@ -0,0 +1,101 @@
+#include "CgeStr.h"
+
+#define INVALID_RUNE    0xFFFD
+
+int CgeUtf8Encode(uint32_t rune, char* data) {
+    if (rune < 0x80) {
+        data[0] = (char)rune;
+        return 1;
+    }
+    if (rune < 0x800) {
+        data[0] = (char)(0xC0 | (rune >> 6));
+        data[1] = (char)(0x80 | (rune & 0x3F));
+        return 2;
+    }
+    if (rune < 0x10000) {
+        if (rune >= 0xD800 && rune <= 0xDFFF)
+            return -1;
+        data[0] = (char)(0xE0 | (rune >> 12));
+        data[1] = (char)(0x80 | ((rune >> 6) & 0x3F));
+        data[2] = (char)(0x80 | (rune & 0x3F));
+        return 3;
+    }
+    if (rune <= 0x10FFFF) {
+        data[0] = (char)(0xF0 | (rune >> 18));
+        data[1] = (char)(0x80 | ((rune >> 12) & 0x3F));
+        data[2] = (char)(0x80 | ((rune >> 6) & 0x3F));
+        data[3] = (char)(0x80 | (rune & 0x3F));
+        return 4;
+    }
+    return -1;
+}
+
+int CgeUtf8EncodeLax(uint32_t rune, char* data) {
+    int result;
+
+    result = CgeUtf8Encode(rune, data);
+    if (result == -1)
+        result = CgeUtf8Encode(INVALID_RUNE, data);
+
+    return result;
+}
+
+int CgeUtf8Decode(const char* data, size_t size, uint32_t* rune) {
+    unsigned char byte = (unsigned char)data[0];
+    int i, n;
+
+    if (size == 0)
+        return -1;
+
+    if (byte < 0x80) {
+        *rune = byte;
+        return 1;
+    }
+
+    if ((byte & 0xE0) == 0xC0) {
+        n = 2;
+        *rune = byte & 0x1F;
+    } else if ((byte & 0xF0) == 0xE0) {
+        n = 3;
+        *rune = byte & 0x0F;
+    } else if ((byte & 0xF8) == 0xF0) {
+        n = 4;
+        *rune = byte & 0x07;
+    } else {
+        return -1;
+    }
+
+    if (size < (size_t)n)
+        return -1;
+
+    for (i = 1; i < n; i++) {
+        byte = (unsigned char)data[i];
+        if ((byte & 0xC0) != 0x80)
+            return -1;
+        *rune = (*rune << 6) | (byte & 0x3F);
+    }
+
+    if ((n == 2 && *rune < 0x80) ||
+        (n == 3 && *rune < 0x800) ||
+        (n == 4 && *rune < 0x10000)) {
+        return -1;
+    }
+
+    if (*rune > 0x10FFFF || (*rune >= 0xD800 && *rune <= 0xDFFF)) {
+        return -1;
+    }
+
+    return n;
+}
+
+int CgeUtf8DecodeLax(const char* data, size_t size, uint32_t* rune) {
+    int result;
+
+    result = CgeUtf8Decode(data, size, rune);
+    if (result == -1) {
+        *rune = INVALID_RUNE;
+        result = 1;
+    }
+
+    return result;
+}