{{- $comment := "" -}}
{{- if eq .from .to -}}
{{- $comment = printf ", line %d" .from -}}
{{- else if eq .from 0 -}}
{{- $comment = printf ", around line %d" .to -}}
{{- else -}}
{{- $comment = printf ", lines %d through %d" .from .to -}}
{{- end -}}
{{- return $comment -}}