From 5cd8e9069a5e78a45932055678eae77a1de4fd66 Mon Sep 17 00:00:00 2001
From: Thomas Voss <mail@thomasvoss.com>
Date: Sat, 13 Apr 2024 00:37:32 +0200
Subject: Add uprop_get_lc()

---
 include/unicode/prop.h          | 10 +++++++++
 lib/unicode/prop/uprop_get_lc.c | 45 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+)
 create mode 100644 lib/unicode/prop/uprop_get_lc.c

diff --git a/include/unicode/prop.h b/include/unicode/prop.h
index cf02a74..76d9200 100644
--- a/include/unicode/prop.h
+++ b/include/unicode/prop.h
@@ -12,6 +12,15 @@ struct rview {
 	size_t len;
 };
 
+struct lcctx {
+	bool az_or_tr             : 1; /* Azeri or Turkish */
+	bool az_tr_after_I        : 1; /* After ‘I’ in Azeri or Turkish */
+	bool az_tr_not_before_dot : 1; /* Not before a dot in Azeri or Turkish */
+	bool eow                  : 1; /* End of word */
+	bool lt                   : 1; /* Lithuanian */
+	bool lt_acc_after         : 1; /* Accent after ‘i’ or ‘j’ in Lithuanian */
+};
+
 struct tcctx {
 	bool az_or_tr   : 1; /* Azeri or Turkish */
 	bool lt_after_i : 1; /* After ‘i’ in Lithuanian */
@@ -173,6 +182,7 @@ enum uprop_nt {
 [[__mlib_uprop_attrs]] rune uprop_get_slc(rune);
 [[__mlib_uprop_attrs]] rune uprop_get_stc(rune);
 [[__mlib_uprop_attrs]] rune uprop_get_suc(rune);
+[[__mlib_uprop_attrs]] struct rview uprop_get_lc(rune, struct lcctx);
 [[__mlib_uprop_attrs]] struct rview uprop_get_tc(rune, struct tcctx);
 [[__mlib_uprop_attrs]] struct rview uprop_get_uc(rune, struct ucctx);
 [[__mlib_uprop_attrs]] struct u8view uprop_get_na1(rune);
diff --git a/lib/unicode/prop/uprop_get_lc.c b/lib/unicode/prop/uprop_get_lc.c
new file mode 100644
index 0000000..4bbdc12
--- /dev/null
+++ b/lib/unicode/prop/uprop_get_lc.c
@@ -0,0 +1,45 @@
+#include "macros.h"
+#include "unicode/prop.h"
+
+#define M(...) ((struct rview)_(__VA_ARGS__))
+#define _(...) \
+	{(const rune[]){__VA_ARGS__}, lengthof(((const rune[]){__VA_ARGS__}))}
+
+struct rview
+uprop_get_lc(rune ch, struct lcctx ctx)
+{
+	if (ch == U'Σ')
+		return ctx.eow ? M(U'ς') : M(U'σ');
+	if (ch == U'İ')
+		return ctx.az_or_tr ? M('i') : M('i', 0x307);
+
+	if (ctx.lt_acc_after) {
+		switch (ch) {
+		case 'I':
+			return M('i', 0x307);
+		case 'J':
+			return M('j', 0x307);
+		case U'Į':
+			return M(U'į', 0x307);
+		}
+	}
+
+	if (ctx.lt) {
+		switch (ch) {
+		case U'Ì':
+			return M('i', 0x307, 0x300);
+		case U'Í':
+			return M('i', 0x307, 0x301);
+		case U'Ĩ':
+			return M('i', 0x307, 0x303);
+		}
+	}
+
+	if (ch == 0x307 && ctx.az_tr_after_I)
+		return M();
+	if (ch == 'I' && ctx.az_tr_not_before_dot)
+		return M(U'ı');
+
+	ch = uprop_get_slc(ch);
+	return M(ch);
+}
-- 
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