Normalizer.eqlIgnoreCase compatibility caseless matching

4 files changed, 163 insertions, 9 deletions

diff --git a/src/FoldData.zig b/src/FoldData.zig
new file mode 100644
index 0000000..139c677
--- /dev/null
+++ b/src/FoldData.zig
@@ -0,0 +1,48 @@
+const std = @import("std");
+const builtin = @import("builtin");
+const compress = std.compress;
+const mem = std.mem;
+
+allocator: mem.Allocator,
+fold: [][]u21 = undefined,
+
+const Self = @This();
+
+pub fn init(allocator: mem.Allocator) !Self {
+    const decompressor = compress.deflate.decompressor;
+    const in_bytes = @embedFile("fold");
+    var in_fbs = std.io.fixedBufferStream(in_bytes);
+    var in_decomp = try decompressor(allocator, in_fbs.reader(), null);
+    defer in_decomp.deinit();
+    var reader = in_decomp.reader();
+
+    const endian = builtin.cpu.arch.endian();
+    var self = Self{
+        .allocator = allocator,
+        .fold = try allocator.alloc([]u21, 0x110000),
+    };
+
+    @memset(self.fold, &.{});
+
+    while (true) {
+        const len: u8 = try reader.readInt(u8, endian);
+        if (len == 0) break;
+        const cp = try reader.readInt(u24, endian);
+        self.fold[cp] = try allocator.alloc(u21, len - 1);
+        for (0..len - 1) |i| {
+            self.fold[cp][i] = @intCast(try reader.readInt(u24, endian));
+        }
+    }
+
+    return self;
+}
+
+pub fn deinit(self: *Self) void {
+    for (self.fold) |slice| self.allocator.free(slice);
+    self.allocator.free(self.fold);
+}
+
+/// Returns the case fold for `cp`.
+pub inline fn caseFold(self: Self, cp: u21) []const u21 {
+    return self.fold[cp];
+}
diff --git a/src/NormData.zig b/src/NormData.zig
index 7c2a09b..3c2f614 100644
--- a/src/NormData.zig
+++ b/src/NormData.zig
@@ -4,6 +4,7 @@ const mem = std.mem;
 const CanonData = @import("CanonData");
 const CccData = @import("CombiningData");
 const CompatData = @import("CompatData");
+const FoldData = @import("FoldData");
 const HangulData = @import("HangulData");
 const NormPropsData = @import("NormPropsData");
 
@@ -12,6 +13,7 @@ ccc_data: CccData,
 compat_data: CompatData,
 hangul_data: HangulData,
 normp_data: NormPropsData,
+fold_data: FoldData,
 
 const Self = @This();
 
@@ -20,6 +22,7 @@ pub fn init(allocator: std.mem.Allocator) !Self {
         .canon_data = try CanonData.init(allocator),
         .ccc_data = try CccData.init(allocator),
         .compat_data = try CompatData.init(allocator),
+        .fold_data = try FoldData.init(allocator),
         .hangul_data = try HangulData.init(allocator),
         .normp_data = try NormPropsData.init(allocator),
     };
@@ -30,5 +33,6 @@ pub fn deinit(self: *Self) void {
     self.ccc_data.deinit();
     self.compat_data.deinit();
     self.hangul_data.deinit();
+    self.fold_data.deinit();
     self.normp_data.deinit();
 }
diff --git a/src/Normalizer.zig b/src/Normalizer.zig
index abe35e5..c68b2ec 100644
--- a/src/Normalizer.zig
+++ b/src/Normalizer.zig
@@ -343,7 +343,102 @@ test "nfkd !ASCII / alloc" {
     try testing.expectEqualStrings("He\u{301}llo World! \u{3a5}\u{301}", result.slice);
 }
 
-// Composition utilities.
+fn caseFold(
+    self: Self,
+    allocator: mem.Allocator,
+    cps: []const u21,
+) ![]const u21 {
+    var cfcps = std.ArrayList(u21).init(allocator);
+    defer cfcps.deinit();
+
+    for (cps) |cp| {
+        const cf = self.norm_data.fold_data.caseFold(cp);
+
+        if (cf.len == 0) {
+            try cfcps.append(cp);
+        } else {
+            try cfcps.appendSlice(cf);
+        }
+    }
+
+    return try cfcps.toOwnedSlice();
+}
+
+fn nfkdCodePoints(
+    self: Self,
+    allocator: mem.Allocator,
+    cps: []const u21,
+) ![]u21 {
+    var dcp_list = std.ArrayList(u21).init(allocator);
+    defer dcp_list.deinit();
+
+    var dc_buf: [18]u21 = undefined;
+
+    for (cps) |cp| {
+        const dc = self.decompose(cp, .nfkd, &dc_buf);
+
+        if (dc.form == .same) {
+            try dcp_list.append(cp);
+        } else {
+            try dcp_list.appendSlice(dc.cps);
+        }
+    }
+
+    self.canonicalSort(dcp_list.items);
+
+    return try dcp_list.toOwnedSlice();
+}
+
+pub fn eqlIgnoreCase(
+    self: Self,
+    allocator: mem.Allocator,
+    a: []const u8,
+    b: []const u8,
+) !bool {
+    if (ascii.isAsciiOnly(a) and ascii.isAsciiOnly(b)) return std.ascii.eqlIgnoreCase(a, b);
+
+    const nfd_a = try self.nfxdCodePoints(allocator, a, .nfd);
+    defer allocator.free(nfd_a);
+    const cf_nfd_a = try self.caseFold(allocator, nfd_a);
+    defer allocator.free(cf_nfd_a);
+    const nfkd_cf_nfd_a = try self.nfkdCodePoints(allocator, cf_nfd_a);
+    defer allocator.free(nfkd_cf_nfd_a);
+    const cf_nfkd_cf_nfd_a = try self.caseFold(allocator, nfkd_cf_nfd_a);
+    defer allocator.free(cf_nfkd_cf_nfd_a);
+    const nfkd_cf_nfkd_cf_nfd_a = try self.nfkdCodePoints(allocator, cf_nfkd_cf_nfd_a);
+    defer allocator.free(nfkd_cf_nfkd_cf_nfd_a);
+
+    const nfd_b = try self.nfxdCodePoints(allocator, b, .nfd);
+    defer allocator.free(nfd_b);
+    const cf_nfd_b = try self.caseFold(allocator, nfd_b);
+    defer allocator.free(cf_nfd_b);
+    const nfkd_cf_nfd_b = try self.nfkdCodePoints(allocator, cf_nfd_b);
+    defer allocator.free(nfkd_cf_nfd_b);
+    const cf_nfkd_cf_nfd_b = try self.caseFold(allocator, nfkd_cf_nfd_b);
+    defer allocator.free(cf_nfkd_cf_nfd_b);
+    const nfkd_cf_nfkd_cf_nfd_b = try self.nfkdCodePoints(allocator, cf_nfkd_cf_nfd_b);
+    defer allocator.free(nfkd_cf_nfkd_cf_nfd_b);
+
+    return mem.eql(u21, nfkd_cf_nfkd_cf_nfd_a, nfkd_cf_nfkd_cf_nfd_b);
+}
+
+test "eqlIgnoreCase" {
+    const allocator = testing.allocator;
+    var data = try NormData.init(allocator);
+    defer data.deinit();
+    var n = Self{ .norm_data = &data };
+
+    try testing.expect(try n.eqlIgnoreCase(allocator, "ascii only!", "ASCII Only!"));
+
+    const a = "Héllo World! \u{3d3}";
+    const b = "He\u{301}llo World! \u{3a5}\u{301}";
+    try testing.expect(try n.eqlIgnoreCase(allocator, a, b));
+
+    const c = "He\u{301}llo World! \u{3d2}\u{301}";
+    try testing.expect(try n.eqlIgnoreCase(allocator, a, c));
+}
+
+// Composition (NFC, NFKC)
 
 fn isHangul(self: Self, cp: u21) bool {
     return cp >= 0x1100 and self.norm_data.hangul_data.syllable(cp) != .none;
@@ -504,11 +599,11 @@ test "nfkc" {
     try testing.expectEqualStrings("Complex char: \u{038E}", result.slice);
 }
 
-/// Tests for equality of `a` and `b` after normalizing to NFD.
+/// Tests for equality of `a` and `b` after normalizing to NFC.
 pub fn eql(self: Self, allocator: mem.Allocator, a: []const u8, b: []const u8) !bool {
-    var norm_result_a = try self.nfd(allocator, a);
+    var norm_result_a = try self.nfc(allocator, a);
     defer norm_result_a.deinit();
-    var norm_result_b = try self.nfd(allocator, b);
+    var norm_result_b = try self.nfc(allocator, b);
     defer norm_result_b.deinit();
 
     return mem.eql(u8, norm_result_a.slice, norm_result_b.slice);
diff --git a/src/main.zig b/src/main.zig
index 59a0fbc..a5afa66 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -49,21 +49,28 @@ pub fn main() !void {
     var iter = std.mem.splitScalar(u8, input, '\n');
 
     var result: usize = 0;
+    var prev_line: []const u8 = "";
     // var result: isize = 0;
     var timer = try std.time.Timer.start();
 
     // while (iter.next()) |cp| result += codePointWidth(@intCast(cp.code));
     // while (iter.next()) |_| result += 1;
     // while (iter.next()) |line| result += strWidth(line, &data);
-    while (iter.next()) |line| {
-        const nfc = try n.nfkc(allocator, line);
-        result += nfc.slice.len;
-        // nfc.deinit();
-    }
+    // while (iter.next()) |line| {
+    //     const nfc = try n.nfkc(allocator, line);
+    //     result += nfc.slice.len;
+    //     // nfc.deinit();
+    // }
     // while (iter.next()) |cp| {
     //     if (cp.code == 'É') std.debug.print("`{u}` Gc: {s}\n", .{ cp.code, @tagName(gencat_data.gc(cp.code)) });
     //     result += 1;
     // }
+    while (iter.next()) |line| {
+        if (try n.eqlIgnoreCase(allocator, prev_line, line)) {
+            result += line.len;
+        }
+        prev_line = line;
+    }
 
     std.debug.print("result: {}, took: {}\n", .{ result, timer.lap() / std.time.ns_per_ms });
 }