47 lines
1.5 KiB
Zig
47 lines
1.5 KiB
Zig
// SPDX-License-Identifier: MIT
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// Copyright (c) 2015-2020 Zig Contributors
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// This file is part of [zig](https://ziglang.org/), which is MIT licensed.
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// The MIT license requires this copyright notice to be included in all copies
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// and substantial portions of the software.
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const std = @import("../std.zig");
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const io = std.io;
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const assert = std.debug.assert;
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/// An OutStream that returns whether the given character has been written to it.
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/// The contents are not written to anything.
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pub fn FindByteOutStream(comptime UnderlyingWriter: type) type {
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return struct {
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const Self = @This();
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pub const Error = UnderlyingWriter.Error;
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pub const Writer = io.Writer(*Self, Error, write);
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underlying_writer: UnderlyingWriter,
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byte_found: bool,
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byte: u8,
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pub fn writer(self: *Self) Writer {
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return .{ .context = self };
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}
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fn write(self: *Self, bytes: []const u8) Error!usize {
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if (!self.byte_found) {
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self.byte_found = blk: {
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for (bytes) |b|
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if (b == self.byte) break :blk true;
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break :blk false;
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};
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}
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return self.underlying_writer.write(bytes);
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}
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};
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}
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pub fn findByteOutStream(byte: u8, underlying_writer: anytype) FindByteOutStream(@TypeOf(underlying_writer)) {
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return FindByteOutStream(@TypeOf(underlying_writer)){
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.underlying_writer = underlying_writer,
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.byte = byte,
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.byte_found = false,
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};
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}
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