Scanner

A port of Java's java.util.Scanner interface to Rust.

Installing / Getting started

Currently, one should clone into this repository and run cargo build. Publishing to crates.io is in the works.

Developing

Code should be styled according to rustfmt. There is currently no behavior in our roadmap that should require the use of an unsafe block.

All unwrap()s should either immediately follow a check that they are safe or include a comment explaining why they are guaranteed to be safe.

Finally, we are following test-driven development. Use the behavior of java.util.Scanner as the reference implementation for a test, with the exception that exceptions should never be raised in a situation where a wrapped return value, e.g., Option, Result, would be appropriate. This will present some places where we will not have parity with Java.

Deploying / Publishing

This section will be updated after we have a working release. In short, we plan on making this available to Cargo and it should be more or less plug-and-play.

Features

Complete

• Scanner.next() -> Option<String>

• Scanner.next_line() -> Option<String>

• Scanner.next_i32() -> Option<i32>

• Support for regular language delimiters

Road Map

1. Support for next[primitive]() methods. We have already implemented next_i32, but this API is likely to be subject to breaking changes in the future: it is easy to make this function generic over, e.g., integral types, floating point types, etc.

Contributing

In general, feel free to work on any feature that is found in java.util.Scanner that we have not implemented here. The repository owner(s) reserve the right to reject pull requests. Here are some tips to make sure your pull request is accepted:

• Comment on the issue for the feature you are writing. If there isn't an issue, make one.

• Get approval from one of the main contributors.

• Include unit tests for your feature. Where there is pairity with java.util.Scanner, ensure those tests match its behavior (see exception caveat under "Developing").