An example of using explicit match narrowing with a cursor to allow for messy input data.

-- rules --
data narrows [a-zA-Z0-9_\-./@]+
data matches ^[a-zA-Z0-9_\-./@]+\.pdf$
plumb to edit

-- initial --
src: bash
dst: ad
wdir: /home/foo/bar
cur: 15
ndata: 48
data: $ zathura my-awesome-pdf.pdf some-other-pdf.pdf

-- processed --
src: bash
dst: ad
wdir: /home/foo/bar
ndata: 18
data: my-awesome-pdf.pdf
