Fildesh is a domain-specific language to create nonlinear pipelines between programs.
It can create pipes between programs with multiple inputs
(eg/sum/add_test.fildesh)
and multiple outputs
(eg/sum/dag.fildesh)
that depend on each other
(eg/sum/cycle.fildesh).
When the dataflow graph is not a tree,
the elastic builtin should be used to avoid deadlocks in the undirected cycles.
# Run script given as command-line args.
docker run -q --rm -a STDOUT ghcr.io/fildesh/fildesh:latest -- \
'|< splice / "Hello world!\n" /' \
'|> stdout'
# Run script given on standard input.
docker run -q --rm -i ghcr.io/fildesh/fildesh:latest - < example/hello.fildesh# Run script after compiling fildesh in ./bld/src/bin/.
cmake -B bld
cmake --build bld --target fildesh
./bld/src/bin/fildesh example/hello.fildesh
# Run script after compiling fildesh with aggressive development presets.
make run 'ARGS=example/hello.fildesh'# Run script after compiling fildesh in ./bazel-bin/src/bin/.
bazel run //:fildesh -- $PWD/example/hello.fildeshConsider writing an end-to-end test that checks whether a program gives an expected result for a particular input. In order to compare the expected and actual results, at least one of them is typically stored as a temporary string or file. With Fildesh, we can keep both in pipes.
The following example (eg/sum/add_test.fildesh) shows how to test a program add that calculates the sum of numbers on each input line.
First, the script constructs an pipe named expect that contains the expected result.
Next, three input lines are constructed and stored in their own pipes named input_line_1, input_linee_2, and input_line_3.
Finally, those lines are spliced together, piped to add, and the result is compared against the expected one.
# Expected result sums on their own lines: 55, 0, and 5050.
splice -o $(OF expect) / "55\n" "0\n" "5050\n" /
# First test input line: Integers from 1 to 10.
|< seq 1 10
|> replace_string -o $(OF input_line_1) "\n" " "
# Second test input line: Nothing.
splice -o $(OF input_line_2) / "" /
# Third test input line: Integers from 1 to 100.
|< seq 1 100
|> replace_string -o $(OF input_line_3) "\n" " "
# Combine the test input lines.
|< splice $(XF input_line_1) / "\n" $(XA input_line_2) "\n" / $(XF input_line_3)
# System under test: Program that sums each line of input numbers.
|- add
# Compare the expected and actual results,
# and exit with a nonzero status if they differ.
|- cmp $(XF expect) -
# Show the diff on stdout if there is any.
|> stdout
$(barrier)
# Indicate success when all previous commands have finished successfully.
|< splice / "Success: `add` produced expected result.\n" /
|> stdout