Details
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Bug
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Status: Resolved
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Major
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Resolution: Fixed
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3.0.0SDK
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None
Description
The behavior of trying to address annotations outside the index appears to be inconsistent.
For example, the following call returns `null`:
String text = "one two three";
tokenBuilder.buildTokens(jCas, text);
List<Token> tokens = new ArrayList<Token>(select(jCas, Token.class));
for (Token token : tokens) {
new AnalyzedText(jCas, token.getBegin(), token.getEnd()).addToIndexes();
}
Token firstToken = tokens.get(0);
AnalyzedText x = jCas.select(AnalyzedText.class).preceding(firstToken, 0).get();
However, this code trying go from the end of the index to before the first item throws a CASRuntime exception:
String text = "Rot wood cheeses dew?";
tokenBuilder.buildTokens(jCas, text);
assertThatExceptionOfType(CASRuntimeException.class)
.isThrownBy(() -> jCas.select(Token.class).backwards().get(4))
.withMessage("CAS does not contain any '" + Token.class.getName() + "' instances shifted by: 4.");
It would seem reasonably to either always return null or to always thrown an exception. If an exception is thrown, it would seem reasonable to introduce a subtype of the CASRuntimeException, e.g. a CASIndexOutOfBounds exception or something the likes. CASRuntimeException seems very general.