CODEWITHSUNDEEP
droolsmvel
Neil
Neil

Reputation: 413

Drools MVEL Dialect - Semi-Colon Requirement

I am just curious as to why my Eclipse Drools compiler (6.5.0) requires semi-colons at the end of statements in the For loop, as below:

Map businessRulesRequest = $root.containsKey("BusinessRulesRequest") ? $root.get("BusinessRulesRequest") : null
Map quoteRequest = businessRulesRequest!=null && businessRulesRequest.containsKey("QuoteRequest") ? businessRulesRequest.get("QuoteRequest") : null
List resultsByKey = quoteRequest!=null && quoteRequest.containsKey("resultsByKey") ? quoteRequest.get("resultsByKey") : new ArrayList()

for (Map search : resultsByKey) {
    Map searchInfo = (search.containsKey("searchInfo") ? search.get("searchInfo") : null);
    String searchName = searchInfo!=null && searchInfo.containsKey("searchName") ? searchInfo.get("searchName").toString() : "";
    List results = (searchName=="quotesMotor" && search.containsKey("results") ? search.get("results") : new ArrayList());
}

If I remove the semi-colons from the first or second lines in the For loop, I get an "unexpected token" error, but not if I remove it from the last line in the loop.

Is it due to Drools evaluating RHS lines as a single statement and so they must be separated inside any loops?

Note: I understand it is not best practice to code assuming semi-colons are not required, however I came across this issue while experimenting and am just interested to know the reason for the compiler error. Thanks.

Upvotes: 1

Views: 490

Answers (1)

Esteban Aliverti
Esteban Aliverti

Reputation: 6322

I guess the answer is because of MVEL itself. Drools may be delegating the entire chunk of code to MVEL to evaluate and execute.

According to this guide, in MVEL the use of a semi-colon is not mandatory in cases where you have 1 statement, or in the last statement of a script.

Hope it helps,

Upvotes: 1

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