Improve truncate_string to be aware of ASCII and UTF8 encodings.

1 files changed, 30 insertions, 23 deletions

diff --git a/ttt.jai b/ttt.jai
index 8a75568..d1e52ab 100644
--- a/ttt.jai
+++ b/ttt.jai
@@ -177,35 +177,42 @@ is_equal_to_any :: (to_compare :string, test_a :string, test_b :string) -> bool
 // The string should have capacity for at least length + 1.
 // The terminating null byte ('\0') is not included in length.
 // Returns the truncated string length.
-truncate_string_utf8 :: (str: string, length: s64) -> length: s64 {
+
+Text_Encoding :: enum u8 #specified {
+    ASCII   :: 1;
+    UTF8    :: 2;
+}
+
+// WIP TODO Ues compiler time code to see the auto bake being used... just for fun, once! :D
+truncate_string :: (str: string, length: s64, $encoding: Text_Encoding = .UTF8) -> length: s64 #no_abc { // TODO Should I use #no_abc ?
     assert(str.data != null);
     assert(str.count >= length);
 
     data := str.data;
     count := str.count;
 
-    // WIP simplify this if/else and try to use only idx or length
-    
-    // Find index of first continuation byte.
-    idx := length;
-    while (idx > 0 && ((data[idx - 1] & 0xC0) == 0x80)) {
-        idx -= 1;
-    }
-    continuation_bytes := length - idx;
+    #if encoding == .UTF8 { // WIP simplify this if/else and try to use only idx or length
+        // Find index of first continuation byte.
+        idx := length;
+        while (idx > 0 && ((data[idx - 1] & 0xC0) == 0x80)) {
+            idx -= 1;
+        }
+        continuation_bytes := length - idx;
     
-    // If string starts with continuation bytes, it's an invalid UTF8 string.
-    if (idx == 0 && continuation_bytes > 0) {
-        length = 0;
-    }
-    // If length truncates some continuation bytes, remove incomplete UTF8 character.
-    else if (idx > 0 // string is not empty
-        // continuation bytes are not complete
-        && !(continuation_bytes == 0 && (data[idx - 1] & 0x80) == 0x00)
-        && !(continuation_bytes == 1 && (data[idx - 1] & 0xE0) == 0xC0)
-        && !(continuation_bytes == 2 && (data[idx - 1] & 0xF0) == 0xE0)
-        && !(continuation_bytes == 3 && (data[idx - 1] & 0xF8) == 0xF0)
-    ) {
-        length -= (continuation_bytes + 1); // Remove '+ 1' start byte.
+        // If string starts with continuation bytes, it's an invalid UTF8 string.
+        if (idx == 0 && continuation_bytes > 0) {
+            length = 0;
+        }
+        // If length truncates some continuation bytes, remove incomplete UTF8 character.
+        else if (idx > 0 // string is not empty
+            // continuation bytes are not complete
+            && !(continuation_bytes == 0 && (data[idx - 1] & 0x80) == 0x00)
+            && !(continuation_bytes == 1 && (data[idx - 1] & 0xE0) == 0xC0)
+            && !(continuation_bytes == 2 && (data[idx - 1] & 0xF0) == 0xE0)
+            && !(continuation_bytes == 3 && (data[idx - 1] & 0xF8) == 0xF0)
+        ) {
+            length -= (continuation_bytes + 1); // Remove '+ 1' start byte.
+        }
     }
 
     memset(data + length, 0, count - length);
@@ -1300,7 +1307,7 @@ main :: () {
     print("--- --- ---\n");
     xpto: string = copy_string("ç€dam");
     memcpy(vb.data, xpto.data, xpto.count);
-    truncate_string_utf8(xx vb, 5);
+    truncate_string(xx vb, 4);
     // memset(xpto.data, 0, 5);
     print(">'%'\n", xpto);
     print(">'%'\n", cast(string)vb);