to run:
Using Atom, in a terminal run
cd app
stack exec glance-exe -- -l -s Main.hs -o ../output.svg

or if that does not work

stack build  --exec "glance-exe -o output.svg -w 500"

View circle.svg with svg-preview plug-in.

To use ghci for the main executable:
stack ghci glance

To use ghci with the test modules:
stack ghci glance:test:glance-test

For all warnings (some warnings duplicated):
stack clean
stack build --test --no-run-tests --ghc-options -Wall

To open documentation for other libraries:
stack haddock --open <package-name>

To build and run in a loop
watch -n2 stack build --exec \"glance-exe examples/fact.hs examples/fact.svg 500\"


GUI:
To build the GUI, first install the system dependencies (follow the directions
here: https://github.com/haskell-gi/haskell-gi#installation)