From ef27c51b8e46f3909a27fd137429b717797f1fd9 Mon Sep 17 00:00:00 2001
From: Sam Atman
Date: Fri, 23 May 2025 16:48:55 -0400
Subject: Add iterateBefore and iterateAfter

These create reverse or forward iterators before or after a Word.  So
this way, the user can get the word at an index, then iterate forward
or back from that word.

Also:

Fixes #59

Which was fixed awhile back, but I don't feel like doing repo surgery
to tag the fix where it happened.  We have blame for that kind of
thing.
---
 src/unicode_tests.zig | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

(limited to 'src/unicode_tests.zig')

diff --git a/src/unicode_tests.zig b/src/unicode_tests.zig
index 18f1814..195fdcb 100644
--- a/src/unicode_tests.zig
+++ b/src/unicode_tests.zig
@@ -287,6 +287,25 @@ test "Segmentation Word Iterator" {
                 } else {
                     try testing.expect(false);
                 }
+                var peek_iter = wb.iterateAfter(this_str, got_word);
+                const peek_1 = peek_iter.next();
+                if (peek_1) |p1| {
+                    const peek_2 = iter.peek();
+                    if (peek_2) |p2| {
+                        std.testing.expectEqualSlices(
+                            u8,
+                            p1.bytes(this_str),
+                            p2.bytes(this_str),
+                        ) catch |err| {
+                            debug.print("Bad peek on line {d} #{d} offset {d}\n", .{ line_iter.line, idx + 1, idx });
+                            return err;
+                        };
+                    } else {
+                        try testing.expect(false);
+                    }
+                } else {
+                    try testing.expectEqual(null, iter.peek());
+                }
                 for (got_word.offset..got_word.offset + got_word.len) |i| {
                     const this_word = wb.wordAtIndex(this_str, i);
                     std.testing.expectEqualSlices(
@@ -337,6 +356,25 @@ test "Segmentation Word Iterator" {
                 } else {
                     try testing.expect(false);
                 }
+                var peek_iter = wb.iterateBefore(this_str, got_word);
+                const peek_1 = peek_iter.prev();
+                if (peek_1) |p1| {
+                    const peek_2 = r_iter.peek();
+                    if (peek_2) |p2| {
+                        std.testing.expectEqualSlices(
+                            u8,
+                            p1.bytes(this_str),
+                            p2.bytes(this_str),
+                        ) catch |err| {
+                            debug.print("Bad peek on line {d} #{d} offset {d}\n", .{ line_iter.line, idx + 1, idx });
+                            return err;
+                        };
+                    } else {
+                        try testing.expect(false);
+                    }
+                } else {
+                    try testing.expectEqual(null, r_iter.peek());
+                }
                 for (got_word.offset..got_word.offset + got_word.len) |i| {
                     const this_word = wb.wordAtIndex(this_str, i);
                     std.testing.expectEqualSlices(
-- 
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