parsing single-character variables fails

[ClaasRostock]

Single character variables in a dict, e.g. $a get not substituted by the value declared in a paramDict.
It seems as if this is in fact related to the variable having a single character only. I.e. variable $aa would work.
@frl000 : This is something we need to look into.

[ClaasRostock]

Hi @frl000
Investigated and found the problem. Single character references are not correctly extracted from block_content.
Resason is the regex used to find them. All occurences of \$\w[\w\[\]]+ need to be replaced with \$\w[\w\[\]]*
(-> using * in regex instead of + ). I will open a PR with the necessary changes and send for your review.