In a situation with multiple changesets, dr-add-to-rule-set is not implemented correctly as demonstrated by the following tests:

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module add-rules
imports libstrategolib

strategies

  main =
    test1
    ; test2
    ; test3
    ; test4

  test1 =
say(!"test1:" )
       ; dr-get-rule-set(|"Test1")
       ; dr-set-rule(|"Test1", 1, 1)
       ; dr-add-rule(|"Test1", 1, 2)
       ; dr-add-rule(|"Test1", 1, 3)
       ; dr-print-rule-set(|"Test1")
       ; dr-lookup-all-rules(|"Test1", 1)
       ; debug(!"test1 res: ")

  test2 =
       say(!"test2:" )
       ; dr-get-rule-set(|"Test2")
       ; dr-set-rule(|"Test2", 1, 1)
       ; dr-start-change-set(|"Test2")
       ; dr-add-rule(|"Test2", 1, 2)
       ; dr-start-change-set(|"Test2")
       ; dr-add-rule(|"Test2", 1, 3)
       ; dr-print-rule-set(|"Test2")
       ; dr-lookup-all-rules(|"Test2", 1)
       ; debug(!"test2 res: ")


  test3 =
say(!"Test3:" )
       ; dr-get-rule-set(|"Test3")
       ; dr-set-rule(|"Test3", 1, 1)
       ; dr-add-rule(|"Test3", 1, 2)
       ; dr-add-rule(|"Test3", 1, 3)
       ; dr-print-rule-set(|"Test3")
       ; dr-lookup-rule(|"Test3", 1)
       ; debug(!"test3 res: ")

  test4 =
       say(!"test4:" )
       ; dr-get-rule-set(|"Test4")
       ; dr-set-rule(|"Test4", 1, 1)
       ; dr-start-change-set(|"Test4")
       ; dr-add-rule(|"Test4", 1, 2)
       ; dr-start-change-set(|"Test4")
       ; dr-add-rule(|"Test4", 1, 3)
       ; dr-print-rule-set(|"Test4")
       ; dr-lookup-rule(|"Test4", 1)
       ; debug(!"test4 res: ")
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The problem is the call <hashtable-get(|key)> tbl2 in add2 below. Instead of doing a get in the hashtable of the rulescope, it should do a lookup in the ruleset rs; this may actually be easy to fix.


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  dr-add-to-rule-set(add1 : ATerm * Hashtable * ATerm * ATerm * ATerm -> ATerm
| label, key, value) =
    ?[ChangeSet(labelset, rmset, tbl1) | rs]
    ; where(
        let add2(|scpid, tbl2, key, value) =
              add1(|scpid, tbl2, key, value)
              <+ {values:
                  ![value | <hashtable-get(|(scpid, key))> tbl1] => values
; if <hashtable-get(|key)> tbl2 => values then
                      <hashtable-remove(|(scpid, key))> tbl1
                    else
                      <hashtable-put(|(scpid, key), values)> tbl1
                    end }
               <+ (<hashtable-get(|key)> tbl2 <+ ![])
                  ; \ values -> <hashtable-put(|(scpid, key), [value | values])> tbl1 \
         in if <iset-contains(|label)> labelset then
<fetch-elem(?RuleScope(_,tbl@Hashtable(hptr)))> rs
               ; add2(|hptr, tbl, key, value)
            else
<dr-add-to-rule-set(add2 | label, key, value)> rs
            end
        end
      )
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(Reported by Bogdan Dumitriu)