Additional unicode primitive functions.

Introduce unicode_version(), icu_unicode_version(), and
unicode_assigned().

The latter requires introducing a new lookup table for the Unicode
General Category, which is generated along with the other Unicode
lookup tables.

Discussion: https://postgr.es/m/CA+TgmoYzYR-yhU6k1XFCADeyj=Oyz2PkVsa3iKv+keM8wp-F_A@mail.gmail.com
Reviewed-by: Peter Eisentraut

1 files changed, 68 insertions, 0 deletions

diff --git a/src/include/common/unicode_category.h b/src/include/common/unicode_category.h
new file mode 100644
index 00000000000..81d38c7411f
--- /dev/null
+++ b/src/include/common/unicode_category.h
@@ -0,0 +1,68 @@
+/*-------------------------------------------------------------------------
+ *
+ * unicode_category.h
+ *	  Routines for determining the category of Unicode characters.
+ *
+ * These definitions can be used by both frontend and backend code.
+ *
+ * Copyright (c) 2017-2023, PostgreSQL Global Development Group
+ *
+ * src/include/common/unicode_category.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef UNICODE_CATEGORY_H
+#define UNICODE_CATEGORY_H
+
+#include "mb/pg_wchar.h"
+
+/*
+ * Unicode General Category Values
+ *
+ * See: https://www.unicode.org/reports/tr44/#General_Category_Values
+ *
+ * The Unicode stability policy guarantees: "The enumeration of
+ * General_Category property values is fixed. No new values will be
+ * added". See: https://www.unicode.org/policies/stability_policy.html
+ *
+ * Numeric values chosen to match corresponding ICU UCharCategory.
+ */
+typedef enum pg_unicode_category
+{
+	PG_U_UNASSIGNED = 0,		/* Cn */
+	PG_U_UPPERCASE_LETTER = 1,	/* Lu */
+	PG_U_LOWERCASE_LETTER = 2,	/* Ll */
+	PG_U_TITLECASE_LETTER = 3,	/* Lt */
+	PG_U_MODIFIER_LETTER = 4,	/* Lm */
+	PG_U_OTHER_LETTER = 5,		/* Lo */
+	PG_U_NONSPACING_MARK = 6,	/* Mn */
+	PG_U_ENCLOSING_MARK = 7,	/* Me */
+	PG_U_SPACING_MARK = 8,		/* Mc */
+	PG_U_DECIMAL_NUMBER = 9,	/* Nd */
+	PG_U_LETTER_NUMBER = 10,	/* Nl */
+	PG_U_OTHER_NUMBER = 11,		/* No */
+	PG_U_SPACE_SEPARATOR = 12,	/* Zs */
+	PG_U_LINE_SEPARATOR = 13,	/* Zl */
+	PG_U_PARAGRAPH_SEPARATOR = 14,	/* Zp */
+	PG_U_CONTROL = 15,			/* Cc */
+	PG_U_FORMAT = 16,			/* Cf */
+	PG_U_PRIVATE_USE = 17,		/* Co */
+	PG_U_SURROGATE = 18,		/* Cs */
+	PG_U_DASH_PUNCTUATION = 19, /* Pd */
+	PG_U_OPEN_PUNCTUATION = 20, /* Ps */
+	PG_U_CLOSE_PUNCTUATION = 21,	/* Pe */
+	PG_U_CONNECTOR_PUNCTUATION = 22,	/* Pc */
+	PG_U_OTHER_PUNCTUATION = 23,	/* Po */
+	PG_U_MATH_SYMBOL = 24,		/* Sm */
+	PG_U_CURRENCY_SYMBOL = 25,	/* Sc */
+	PG_U_MODIFIER_SYMBOL = 26,	/* Sk */
+	PG_U_OTHER_SYMBOL = 27,		/* So */
+	PG_U_INITIAL_PUNCTUATION = 28,	/* Pi */
+	PG_U_FINAL_PUNCTUATION = 29 /* Pf */
+} pg_unicode_category;
+
+extern pg_unicode_category unicode_category(pg_wchar ucs);
+const char *unicode_category_string(pg_unicode_category category);
+const char *unicode_category_abbrev(pg_unicode_category category);
+
+#endif							/* UNICODE_CATEGORY_H */