README.md

Flow Examples

examples contains a set of example flows used to demonstrate flow (flowc, flowr, flowstdlib), the different semantics and characteristics of flows that can be written, and test them to ensure they continue to run correctly over time.

Each subdirectory holds a self-contained flow example, with flow definition, docs etc and some of them provide their own function implementations that get compiled to WASM by flowc when the flow is compiled.

Flow enables higher levels of parallelization of execution of 'jobs' within flows by allowing many jobs to be run in parallel, which then may be executed out of order. This can lead to unpredictable ordering of the output values of some operations. To embrace this, the examples typically avoid requiring a specific ordering of the output values.

Environment Variable Requirements

If you are using make, then temporary additions to $PATH will be made for you so that the required flow executables (flowcand flowr) are found.

However, if you wish to run an example from the command line, then you will need to make sure the flowc and flowr executables (built by the Makefile) are in your path (or use the full path when running them).

You can do this using:

export PATH="target/debug:target/release:$PATH"

from the project root directory.

Building all examples

cargo test

Builds all examples to make sure they compile, but they are not run.

cargo build --examples

Builds all examples

Running one example

cargo run --example $example-name"

This can be run from the root folder or the flowr folder. The named example is build and run.

The flow will be run with the arguments and standard input defined in files within each directory (if they are not present then those args or input is zero).

Testing one example

cargo test --example $example-name

The flow will be run with the arguments and standard input defined in files within each directory (if they are not present then those args or input is zero) and the output compared to the expected output (defined in files in the directory). If the output does not match the expected output then the test fails.

Testing all examples

cargo test --examples

Will run the tests in all examples.