encoding.c: Support using wchar_t strings with the text decoder API.

src/libespeak-ng/encoding.c

 	return c1 + (c2 << 8);
 }
 
+static uint32_t
+string_decoder_getc_wchar(espeak_ng_TEXT_DECODER *decoder)
+{
+	wchar_t c = *(const wchar_t *)decoder->current;
+	decoder->current += sizeof(wchar_t);
+	return c;
+}
+
 typedef struct
 {
 	uint32_t (*get)(espeak_ng_TEXT_DECODER *decoder);
 	return ENS_OK;
 }
 
+espeak_ng_STATUS
+text_decoder_decode_wstring(espeak_ng_TEXT_DECODER *decoder,
+                            const wchar_t *string,
+                            int length)
+{
+	decoder->get = string_decoder_getc_wchar;
+	decoder->codepage = NULL;
+	decoder->current = (const uint8_t *)string;
+	decoder->end = (const uint8_t *)(string + length);
+	return ENS_OK;
+}
+
 int
 text_decoder_eof(espeak_ng_TEXT_DECODER *decoder)
 {

src/libespeak-ng/encoding.h

                            int length,
                            espeak_ng_ENCODING encoding);
 
+espeak_ng_STATUS
+text_decoder_decode_wstring(espeak_ng_TEXT_DECODER *decoder,
+                            const wchar_t *string,
+                            int length);
+
 int
 text_decoder_eof(espeak_ng_TEXT_DECODER *decoder);
 

tests/encoding.c

 	destroy_text_decoder(decoder);
 }
 
+void
+test_wchar_decoder()
+{
+	printf("testing wchar_t decoder\n");
+
+	espeak_ng_TEXT_DECODER *decoder = create_text_decoder();
+
+	assert(text_decoder_decode_wstring(decoder, L"aG\xA0\x2045", 4) == ENS_OK);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 'a');
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 'G');
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0xA0);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x2045);
+	assert(text_decoder_eof(decoder) == 1);
+
+	destroy_text_decoder(decoder);
+}
+
 int
 main(int argc, char **argv)
 {
 	test_utf_8_encoding();
 	test_iso_10646_ucs_2_encoding();
 
+	test_wchar_decoder();
+
 	printf("done\n");
 
 	return EXIT_SUCCESS;