1 files changed, 102 insertions, 0 deletions

diff --git a/src/WordBreak.zig b/src/WordBreak.zig
new file mode 100644
index 0000000..9044740
--- /dev/null
+++ b/src/WordBreak.zig
@@ -0,0 +1,102 @@
+//! Word Breaking Algorithm.
+
+const WordBreakProperty = enum(u5) {
+    none,
+    Double_Quote,
+    Single_Quote,
+    Hebrew_Letter,
+    CR,
+    LF,
+    Newline,
+    Extend,
+    Regional_Indicator,
+    Format,
+    Katakana,
+    ALetter,
+    MidLetter,
+    MidNum,
+    MidNumLet,
+    Numeric,
+    ExtendNumLet,
+    ZWJ,
+    WSegSpace,
+};
+
+s1: []u16 = undefined,
+s2: []u5 = undefined,
+
+const WordBreak = @This();
+
+pub fn init(allocator: Allocator) Allocator.Error!WordBreak {
+    var wb: WordBreak = undefined;
+    try wb.setup(allocator);
+    return wb;
+}
+
+pub fn setup(wb: *WordBreak, allocator: Allocator) Allocator.Error!void {
+    wb.setupImpl(allocator) catch |err| {
+        switch (err) {
+            error.OutOfMemory => |e| return e,
+            else => unreachable,
+        }
+    };
+}
+
+inline fn setupImpl(wb: *WordBreak, allocator: Allocator) !void {
+    const decompressor = compress.flate.inflate.decompressor;
+    const in_bytes = @embedFile("wbp");
+    var in_fbs = std.io.fixedBufferStream(in_bytes);
+    var in_decomp = decompressor(.raw, in_fbs.reader());
+    var reader = in_decomp.reader();
+
+    const endian = builtin.cpu.arch.endian();
+
+    const stage_1_len: u16 = try reader.readInt(u16, endian);
+    wb.s1 = try allocator.alloc(u16, stage_1_len);
+    errdefer allocator.free(wb.s1);
+    for (0..stage_1_len) |i| wb.s1[i] = try reader.readInt(u16, endian);
+
+    const stage_2_len: u16 = try reader.readInt(u16, endian);
+    wb.s2 = try allocator.alloc(u5, stage_2_len);
+    errdefer allocator.free(wb.s2);
+    for (0..stage_2_len) |i| wb.s2[i] = @intCast(try reader.readInt(u8, endian));
+    var count_0: usize = 0;
+    for (wb.s2) |nyb| {
+        if (nyb == 0) count_0 += 1;
+    }
+}
+
+pub fn deinit(wordbreak: *const WordBreak, allocator: mem.Allocator) void {
+    allocator.free(wordbreak.s1);
+    allocator.free(wordbreak.s2);
+}
+
+/// Returns the word break property type for `cp`.
+pub fn breakProperty(wordbreak: *const WordBreak, cp: u21) WordBreakProperty {
+    return @enumFromInt(wordbreak.s2[wordbreak.s1[cp >> 8] + (cp & 0xff)]);
+}
+
+test "Word Break Properties" {
+    const wb = try WordBreak.init(testing.allocator);
+    defer wb.deinit(testing.allocator);
+    try testing.expectEqual(.CR, wb.breakProperty('\r'));
+    try testing.expectEqual(.LF, wb.breakProperty('\n'));
+    try testing.expectEqual(.Hebrew_Letter, wb.breakProperty('ש'));
+    try testing.expectEqual(.Katakana, wb.breakProperty('\u{30ff}'));
+}
+
+fn testAllocations(allocator: Allocator) !void {
+    const wb = try WordBreak.init(allocator);
+    wb.deinit(allocator);
+}
+
+test "allocation safety" {
+    try testing.checkAllAllocationFailures(testing.allocator, testAllocations, .{});
+}
+
+const std = @import("std");
+const builtin = @import("builtin");
+const compress = std.compress;
+const mem = std.mem;
+const Allocator = mem.Allocator;
+const testing = std.testing;