ground_truth/libraries/src/FileIO/README.md

File I/O

The FileIO module provides basic file I/O operations. Right now, these are limited to reading bytes from a file, and writing bytes to a file. The API is intentionally limited in scope and will be expanded later.

Unlike other modules in the libraries repo, the FileIO module will not compile or run correctly without a language-specific implementation file. Language-specific implementation files are provided for C#/.NET, Java, and Javascript. (Python and Golang support are planned.) Concretely, to use FileIO in your code, you must:

1. include and import the FileIO module as you would any other library module
2. incorporate the corresponding language-specific implementation file (e.g. FileIO.cs) when building or running your program

For example, to run a Program.dfy file that depends on the FileIO module, run the following. (This assumes you have the libraries repository checked out within the working directory.)

# C#/.NET
$ dafny run Program.dfy --input libraries/src/FileIO/FileIO.cs

# Java
$ dafny run Program.dfy --target:java --input libraries/src/FileIO/FileIO.java

# Javascript
$ dafny run Program.dfy --target:js --input libraries/src/FileIO/FileIO.js

(If you aren't using dafny run to run your program, then you should instead integrate the appropriate language-specific implementation file in your build system.)

The examples/FileIO directory contains more detailed examples of how to use the FileIO module.