Forgotten APL Influences (2016)

I recently read the paper that introduced cyclomatic complexity (and led to linters many of us use today such as ones in golanglint-ci), and discovered that the prototype was written in APL:

The tool, FLOW, was written in APL to input the source code from Fortran files on disk. FLOW would then break a Fortran job into distinct subroutines and analyze the control structure of each subroutine.