Sample flows

The project includes a number of sample 'flows' that have been developed during the development of the compiler and the run-time to drive the project development and demonstrate it working.

They also serve as a type of regression test to make sure we don't break any of the semantics that the samples rely on.

They range from the extremely simple "hello-world" example to more complex ones like generation of a fibonacci series or a mandlebrot set image.

Structure of each sample

Each sample directory contains:

• A DESCRIPTION.md file that:
  • describes what the Flow does
  • lists the features of flow that this sample uses and demonstrates
• A context.toml file that is the root file of the flow description
• Files used in the automated testing of each sample:
  • test_arguments.txt the arguments to be passed to the flow when running it
  • test_input.txt the input supplied to the flow when running it
  • expected_output.txt the output that the flow is expected to produce when invoked with text_arguments.txt and input test_input.txt

Compiling and Running the Samples

The samples set has now been converted to a rust crate with a custom build script.

Using cargo build -p samples causes the build script to run, and it compiles in-place the samples using the flowc compiler.

Using cargo run -p samples causes the sample runner in main.rs to run. It looks for sub-folders in the samples folder and then executes the sample within, and compares the actual output with the expected output and fails if they are different.

The samples crate is one of the default-members of the flow workspace project, so it is used if no particular package is supplied, thus the samples can also be built and run using:

• cargo build : compile the samples using flowc
• cargo run : run the samples using flowr

As other default-members are added to the workspace over time, those commands may do other things, so just be aware that if you onyl want to run the samples the -p samples option above will be safer.