Add pg_iswalpha() and related functions.

Per-character pg_locale_t APIs. Useful for tsearch parsing and
potentially other places.

Significant overlap with the regc_wc_isalpha() and related functions
in regc_pg_locale.c, but this change leaves those intact for
now.

Discussion: https://postgr.es/m/0151ad01239e2cc7b3139644358cf8f7b9622ff7.camel@j-davis.com

2 files changed, 172 insertions, 0 deletions

diff --git a/src/include/utils/pg_locale.h b/src/include/utils/pg_locale.h
index 7e83594fbaf..009f5334a87 100644
--- a/src/include/utils/pg_locale.h
+++ b/src/include/utils/pg_locale.h
@@ -208,6 +208,18 @@ extern size_t pg_strxfrm_prefix(char *dest, const char *src, size_t destsize,
 extern size_t pg_strnxfrm_prefix(char *dest, size_t destsize, const char *src,
 								 ssize_t srclen, pg_locale_t locale);
 
+extern bool pg_iswdigit(pg_wchar wc, pg_locale_t locale);
+extern bool pg_iswalpha(pg_wchar wc, pg_locale_t locale);
+extern bool pg_iswalnum(pg_wchar wc, pg_locale_t locale);
+extern bool pg_iswupper(pg_wchar wc, pg_locale_t locale);
+extern bool pg_iswlower(pg_wchar wc, pg_locale_t locale);
+extern bool pg_iswgraph(pg_wchar wc, pg_locale_t locale);
+extern bool pg_iswprint(pg_wchar wc, pg_locale_t locale);
+extern bool pg_iswpunct(pg_wchar wc, pg_locale_t locale);
+extern bool pg_iswspace(pg_wchar wc, pg_locale_t locale);
+extern pg_wchar pg_towupper(pg_wchar wc, pg_locale_t locale);
+extern pg_wchar pg_towlower(pg_wchar wc, pg_locale_t locale);
+
 extern int	builtin_locale_encoding(const char *locale);
 extern const char *builtin_validate_locale(int encoding, const char *locale);
 extern void icu_validate_locale(const char *loc_str);
diff --git a/src/include/utils/pg_locale_c.h b/src/include/utils/pg_locale_c.h
new file mode 100644
index 00000000000..11a0f996db2
--- /dev/null
+++ b/src/include/utils/pg_locale_c.h
@@ -0,0 +1,160 @@
+/*-----------------------------------------------------------------------
+ *
+ * PostgreSQL locale utilities
+ *
+ * src/include/utils/pg_locale_c.h
+ *
+ * Copyright (c) 2002-2025, PostgreSQL Global Development Group
+ *
+ *-----------------------------------------------------------------------
+ */
+
+#ifndef _PG_LOCALE_C_
+#define _PG_LOCALE_C_
+
+/*
+ * Hard-wired character properties for C locale
+ */
+
+#define PG_ISDIGIT	0x01
+#define PG_ISALPHA	0x02
+#define PG_ISALNUM	(PG_ISDIGIT | PG_ISALPHA)
+#define PG_ISUPPER	0x04
+#define PG_ISLOWER	0x08
+#define PG_ISGRAPH	0x10
+#define PG_ISPRINT	0x20
+#define PG_ISPUNCT	0x40
+#define PG_ISSPACE	0x80
+
+static const unsigned char pg_char_properties[128] = {
+	 /* NUL */ 0,
+	 /* ^A */ 0,
+	 /* ^B */ 0,
+	 /* ^C */ 0,
+	 /* ^D */ 0,
+	 /* ^E */ 0,
+	 /* ^F */ 0,
+	 /* ^G */ 0,
+	 /* ^H */ 0,
+	 /* ^I */ PG_ISSPACE,
+	 /* ^J */ PG_ISSPACE,
+	 /* ^K */ PG_ISSPACE,
+	 /* ^L */ PG_ISSPACE,
+	 /* ^M */ PG_ISSPACE,
+	 /* ^N */ 0,
+	 /* ^O */ 0,
+	 /* ^P */ 0,
+	 /* ^Q */ 0,
+	 /* ^R */ 0,
+	 /* ^S */ 0,
+	 /* ^T */ 0,
+	 /* ^U */ 0,
+	 /* ^V */ 0,
+	 /* ^W */ 0,
+	 /* ^X */ 0,
+	 /* ^Y */ 0,
+	 /* ^Z */ 0,
+	 /* ^[ */ 0,
+	 /* ^\ */ 0,
+	 /* ^] */ 0,
+	 /* ^^ */ 0,
+	 /* ^_ */ 0,
+	 /* */ PG_ISPRINT | PG_ISSPACE,
+	 /* !  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* "  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* #  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* $  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* %  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* &  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* '  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* (  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* )  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* *  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* +  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* ,  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* -  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* .  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* /  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* 0  */ PG_ISDIGIT | PG_ISGRAPH | PG_ISPRINT,
+	 /* 1  */ PG_ISDIGIT | PG_ISGRAPH | PG_ISPRINT,
+	 /* 2  */ PG_ISDIGIT | PG_ISGRAPH | PG_ISPRINT,
+	 /* 3  */ PG_ISDIGIT | PG_ISGRAPH | PG_ISPRINT,
+	 /* 4  */ PG_ISDIGIT | PG_ISGRAPH | PG_ISPRINT,
+	 /* 5  */ PG_ISDIGIT | PG_ISGRAPH | PG_ISPRINT,
+	 /* 6  */ PG_ISDIGIT | PG_ISGRAPH | PG_ISPRINT,
+	 /* 7  */ PG_ISDIGIT | PG_ISGRAPH | PG_ISPRINT,
+	 /* 8  */ PG_ISDIGIT | PG_ISGRAPH | PG_ISPRINT,
+	 /* 9  */ PG_ISDIGIT | PG_ISGRAPH | PG_ISPRINT,
+	 /* :  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* ;  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* <  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* =  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* >  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* ?  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* @  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* A  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* B  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* C  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* D  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* E  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* F  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* G  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* H  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* I  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* J  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* K  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* L  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* M  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* N  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* O  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* P  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* Q  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* R  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* S  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* T  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* U  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* V  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* W  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* X  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* Y  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* Z  */ PG_ISALPHA | PG_ISUPPER | PG_ISGRAPH | PG_ISPRINT,
+	 /* [  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* \  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* ]  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* ^  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* _  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* `  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* a  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* b  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* c  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* d  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* e  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* f  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* g  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* h  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* i  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* j  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* k  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* l  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* m  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* n  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* o  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* p  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* q  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* r  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* s  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* t  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* u  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* v  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* w  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* x  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* y  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* z  */ PG_ISALPHA | PG_ISLOWER | PG_ISGRAPH | PG_ISPRINT,
+	 /* {  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* |  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* }  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* ~  */ PG_ISGRAPH | PG_ISPRINT | PG_ISPUNCT,
+	 /* DEL */ 0
+};
+
+#endif							/* _PG_LOCALE_C_ */