SUBSTR with negativ length

hi,

i just have checked a couple of implementations regarding the behaviour of
negative length for SUBSTR sparql function. what i tried to achieve is to
get
the last two characters of a string, but this doesn't really work anywhere.

a use case : number padding

example :

SELECT ?padded WHERE {
  ?s ?p ?num FILTER(isNumeric(?num) && ?num<10000000) .
  BIND(SUBSTR(CONCAT("0000000", ?num),STRLEN(?num),-7) AS ?padded)
}

any thoughts?

wkr jürgen


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