feat: Initial setup

1 files changed, 75 insertions, 0 deletions

diff --git a/src/main.zig b/src/main.zig
new file mode 100644
index 0000000..c65a36b
--- /dev/null
+++ b/src/main.zig
@@ -0,0 +1,75 @@
+const std = @import("std");
+const File = std.fs.File;
+const Writer = std.fs.File.Writer;
+
+pub fn main() !void {
+    const in = std.io.getStdIn();
+    const out = std.io.getStdOut();
+    Uf.init().streamCopy(in, out) catch |err| {
+        try std.io.getStdErr().writer().print("Error {}", .{err});
+    };
+}
+
+const buf_size = 1_000_000;
+
+const Uf = struct {
+    const Self = @This();
+
+    var out_buf: [buf_size]u8 = undefined;
+    var out_index: u32 = 0;
+
+    fn init() *const Self {
+        return &Self{};
+    }
+
+    fn flush(_: *const Self, out: Writer) !void {
+        _ = try out.write(out_buf[0..out_index]);
+        out_index = 0;
+    }
+
+    fn writeChar(self: *const Self, out: Writer, c: u8) !void {
+        if (out_index >= buf_size) {
+            try self.flush(out);
+        }
+        out_buf[out_index] = c;
+        out_index += 1;
+    }
+
+    fn streamCopy(self: *const Self, in: File, out: File) !void {
+        const reader = in.reader();
+        const writer = out.writer();
+
+        var hit = false;
+        var second = false;
+        var in_buf: [buf_size]u8 = undefined;
+        while (true) {
+            const size = try reader.read(&in_buf);
+
+            for (in_buf[0..size]) |c| {
+                if (hit and c == '\n') {
+                    if (second == false) {
+                        second = true;
+                    } else {
+                        continue;
+                    }
+                } else if (hit and c != '\n') {
+                    if (second) {
+                        try self.writeChar(writer, '\n');
+                    }
+                    hit = false;
+                    second = false;
+                } else if (c == '\n') {
+                    hit = true;
+                    continue;
+                }
+
+                try self.writeChar(writer, c);
+            }
+
+            if (size != in_buf.len) {
+                try self.flush(writer);
+                return;
+            }
+        }
+    }
+};