platform/packages/code_buffer/README.md
2021-03-16 08:14:28 +08:00

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# code_buffer
[![Pub](https://img.shields.io/pub/v/code_buffer.svg)](https://pub.dartlang.org/packages/code_buffer)
[![build status](https://travis-ci.org/thosakwe/code_buffer.svg)](https://travis-ci.org/thosakwe/code_buffer)
An advanced StringBuffer geared toward generating code, and source maps.
# Installation
In your `pubspec.yaml`:
```yaml
dependencies:
code_buffer: ^1.0.0
```
# Usage
Use a `CodeBuffer` just like any regular `StringBuffer`:
```dart
String someFunc() {
var buf = new CodeBuffer();
buf
..write('hello ')
..writeln('world!');
return buf.toString();
}
```
However, a `CodeBuffer` supports indentation.
```dart
void someOtherFunc() {
var buf = new CodeBuffer();
// Custom options...
var buf = new CodeBuffer(newline: '\r\n', space: '\t', trailingNewline: true);
// Any following lines will have an incremented indentation level...
buf.indent();
// And vice-versa:
buf.outdent();
}
```
`CodeBuffer` instances keep track of every `SourceSpan` they create.
This makes them useful for codegen tools, or to-JS compilers.
```dart
void someFunc(CodeBuffer buf) {
buf.write('hello');
expect(buf.lastLine.text, 'hello');
buf.writeln('world');
expect(buf.lastLine.lastSpan.start.column, 5);
}
```
You can copy a `CodeBuffer` into another, heeding indentation rules:
```dart
void yetAnotherFunc(CodeBuffer a, CodeBuffer b) {
b.copyInto(a);
}
```