Introduce 1 or more statistics which can be used to measure code "quality"

Candidates for the metrics/input to the metrics:

• Number of warnings
• Complex helper sizes
• Number of lines in each definition
• use of [n>1]
• Conditional (IF/MAP) rows instead of DATASETs
• Patterns that have been added to the optimizer.
• Strong similarities between two graphs.
• Non global outputs
• EXISTS - especially on a scalar. (Should this be illegal?)

beware - you get what you measure, so make sure that they really do reflect poor practice, or constructs that should be avoided because of implementation restrictions.