Common (stringUtil): adds ffUtf8CharLenWidth

2026-09-12 10:22:12 +02:00 · 2026-05-26 16:11:30 +08:00
parent 173d9695b6
commit 88c3b7d118
4 changed files with 218 additions and 79 deletions
@@ -0,0 +1,118 @@
+#include "common/stringUtils.h"
+#include "common/textModifier.h"
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static void verify(bool expression, const char* expressionStr, int lineNo) {
+    if (expression) {
+        return;
+    }
+
+    fprintf(stderr, FASTFETCH_TEXT_MODIFIER_ERROR "[%d] %s\n" FASTFETCH_TEXT_MODIFIER_RESET, lineNo, expressionStr);
+    exit(1);
+}
+
+#define VERIFY(expression) verify((expression), #expression, __LINE__)
+
+int main(void) {
+    {
+        uint8_t width = 255;
+        uint8_t bytes = ffUtf8CharLenWidth("", 0, &width);
+        VERIFY(bytes == 0);
+        VERIFY(width == 0);
+    }
+
+    {
+        uint8_t width = 0;
+        uint8_t bytes = ffUtf8CharLenWidth("A", 1, &width);
+        VERIFY(bytes == 1);
+        VERIFY(width == 1);
+    }
+
+    {
+        const char* ch = "\xE6\x96\x87"; // 文 U+6587
+        uint8_t width = 0;
+        uint8_t bytes = ffUtf8CharLenWidth(ch, 3, &width);
+        int expected = mk_wcwidth(0x6587);
+        VERIFY(bytes == 3);
+        VERIFY(width == (uint8_t) (expected < 0 ? 0 : expected));
+    }
+
+    {
+        const char* combining = "\xCC\x81"; // U+0301
+        uint8_t width = 0;
+        uint8_t bytes = ffUtf8CharLenWidth(combining, 2, &width);
+        int expected = mk_wcwidth(0x0301);
+        VERIFY(bytes == 2);
+        VERIFY(width == (uint8_t) (expected < 0 ? 0 : expected));
+    }
+
+    {
+        uint8_t width = 0;
+        uint8_t bytes = ffUtf8CharLenWidth("\xE6\x96\x87", 1, &width); // truncated
+        VERIFY(bytes == 1);
+        VERIFY(width == 1);
+    }
+
+    {
+        uint8_t width = 0;
+        uint8_t bytes = ffUtf8CharLenWidth("\xE6"
+                                           "A",
+            2,
+            &width); // invalid continuation
+        VERIFY(bytes == 1);
+        VERIFY(width == 1);
+    }
+
+    {
+        VERIFY(ffUtf8StrWidth("abc", 3) == 3);
+    }
+
+    {
+        const char* mixed = "A"
+                            "\xE6\x96\x87"
+                            "B";
+        int wide = mk_wcwidth(0x6587);
+        uint32_t expected = 2 + (uint32_t) (wide < 0 ? 0 : wide);
+        VERIFY(ffUtf8StrWidth(mixed, 5) == expected);
+    }
+
+    {
+        const char* combining = "A\xCC\x81";
+        int wCombining = mk_wcwidth(0x0301);
+        uint32_t expected = 1 + (uint32_t) (wCombining < 0 ? 0 : wCombining);
+        VERIFY(ffUtf8StrWidth(combining, 3) == expected);
+    }
+
+    {
+        VERIFY(ffUtf8StrWidth("\xE6"
+                              "A",
+                   2) == 2);
+    }
+
+    {
+        VERIFY(ffUtf8StrWidth("", 0) == 0);
+        VERIFY(ffUtf8StrWidth("A\0B", 3) == 1);
+    }
+
+    {
+        const char* combining = "\xCC\x81";
+        int wCombining = mk_wcwidth(0x0301);
+        uint32_t normalized = (uint32_t) (wCombining < 0 ? 0 : wCombining);
+        uint32_t expected = normalized > 0 ? normalized : 2;
+        VERIFY(ffUtf8StrWidth(combining, 2) == expected);
+    }
+
+    {
+        const char* emoji = "\xF0\x9F\x98\x80"; // U+1F600 😀
+        uint8_t width = 0;
+        uint8_t bytes = ffUtf8CharLenWidth(emoji, 4, &width);
+        VERIFY(bytes == 4);
+        VERIFY(width == 2); // Most emoji are double-width
+    }
+
+    puts("\033[32mAll tests passed!" FASTFETCH_TEXT_MODIFIER_RESET);
+    return 0;
+}