X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=functions%2Fuchar%2Fmbrtoc16.c;fp=functions%2Fuchar%2Fmbrtoc16.c;h=60b9f41aeaec91763da1173d08d0b989711f46b0;hb=db384a5b4db8611b58a125a1f8504a3785f26566;hp=0000000000000000000000000000000000000000;hpb=97a8b0bcf45b59947d8f0953c45204829b9e71ed;p=pdclib

diff --git a/functions/uchar/mbrtoc16.c b/functions/uchar/mbrtoc16.c
new file mode 100644
index 0000000..60b9f41
--- /dev/null
+++ b/functions/uchar/mbrtoc16.c
@@ -0,0 +1,99 @@
+/* size_t mbrtoc16(
+    char16_t    *restrict   pc16,
+    const char  *restrict   s, 
+    size_t                  n,
+    mbstate_t   *restrict   ps);
+
+   This file is part of the Public Domain C Library (PDCLib).
+   Permission is granted to use, modify, and / or redistribute at will.
+*/
+
+#ifndef REGTEST
+#include <uchar.h>
+#include <errno.h>
+#include <stdint.h>
+#include <assert.h>
+#include <_PDCLIB_encoding.h>
+#include <_PDCLIB_locale.h>
+
+size_t mbrtoc16_l(
+    char16_t    *restrict   pc16,
+    const char  *restrict   s, 
+    size_t                  n,
+    mbstate_t   *restrict   ps,
+    locale_t     restrict   l
+)
+{
+    size_t dstlen = 1;
+    size_t nr = n;
+
+    if(!l->_Codec->__mbstoc16s) {
+        // No UTF-16 support in codec. Must synthesize on top of UCS-4 support.
+
+        if(ps->_Surrogate) {
+            // If a pending surrogate is stored in the state
+            *pc16 = ps->_Surrogate;
+            ps->_Surrogate = 0;
+            return (size_t) -3;
+        }
+
+        char32_t c32;
+        size_t res = mbrtoc32_l(&c32, s, n, ps, l);
+        if(res != (size_t) -1) {
+            // Conversion was successful. Check for surrogates
+            if(c32 <= 0xFFFF) {
+                // BMP char
+                *pc16 = c32;
+            } else {
+                // Supplementary char
+                *pc16 = 0xD800 | (c32 >> 10);
+                ps->_Surrogate = 0xDC00 | (c32 & 0x3FF);
+            }
+        }
+        return res;
+    } else if(l->_Codec->__mbstoc16s(&pc16, &dstlen, &s, &nr, ps)) {
+        // Successful conversion
+        if(dstlen == 0) {
+            // A character was output
+            if(nr == n) {
+                // The output character resulted entirely from stored state
+                return (size_t) -3;
+            } else if(pc16[-1] == 0) {
+                // Was null character
+                return 0;
+            } else {
+                // Count of processed characters
+                return n - nr;
+            }
+        } else {
+            assert(nr == 0 && "Must have processed whole input");
+            return (size_t) -2;
+        }
+    } else {
+        // Failed conversion
+        errno = EILSEQ;
+        return (size_t) -1;
+    }
+}
+
+size_t mbrtoc16(
+    char16_t    *restrict   pc16,
+    const char  *restrict   s, 
+    size_t                  n,
+    mbstate_t   *restrict   ps
+)
+{
+    return mbrtoc16_l(pc16, s, n, ps, _PDCLIB_threadlocale());
+}
+
+#endif
+
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main( void )
+{
+    TESTCASE( NO_TESTDRIVER );
+    return TEST_RESULTS;
+}
+#endif