Print class final Introduction

A sequence that is a literal text value that contains no escape codes.

While not strictly necessary for output, this type has two main purposes:

1. A sealed subtype represntation of Sequence for decoding.
2. A safe way to represent user-provided text that should not contain escape codes, with optional validation.

See also: AnsiDecoder for decoding ANSI escape codes from a string.

Output

Print writes the text value to the output at the current cursor position.

Assuming a starting cursor position of █:

█

Print writes the text value to the output, advancing the cursor to the current position after the text:

sink.writeAnsi(Print('Hello, World!'));

Resulting in:

Hello, World!█

Note that String.length is not a reliable way to determine the cursor position after writing a Print sequence, as it does not account for extended characters. See package:characters for working with Unicode characters and grapheme clusters in a predictable way, including measuring the width of text.

Example

final sequence = Print('Hello, World!');
final buffer = StringBuffer();
sequence.writeAnsiString(buffer);
print(buffer.toString()); // 'Hello, World!'

By default, Print will escape any escape or control characters:

final sequence = Print('\x1BHello\nWorld!');
final buffer = StringBuffer();
sequence.writeAnsiString(buffer);
print(buffer.toString()); // '\\x1BHello\\nWorld!'

However, there are options to either:

• Allow ASCII control characters (e.g. \x07 for bell) with allowAscii.
• Check for invalid characters and throw instead with Print.checkInvalid.