stringLiteral parser of JavaTokenParsers ends up with a Stackoverflow error since scala upgrade #371
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@sjrd you remember anything about that? |
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The "possessive quantifier" is necessary in that case on the JVM: Your stack may vary. Your regex library may different on other platforms; the linked PR is for supporting JS. ("Java regular expressions support possessive quantifiers, but JavaScript does not," says an undergrad web page.) https://next.sonarqube.com/sonarqube/coding_rules?open=java%3AS5998&rule_key=java%3AS5998 https://docs.oracle.com/javase/tutorial/essential/regex/quant.html |
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A good interview question would be, "So are you greedy, reluctant, or possessive?" |
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Has anyone tried to determine whether it's possible here for us to both be JS-friendly, and avoid consuming so much stack on the JVM? |
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reproduction steps
using Scala 2.12 or 2.13
problem
In the process of upgrading scala from 2.11 to 2.13, we are now hitting a StackOverflow error when using the scala parser combinator with the exact same code.
After investigating that issue, it turns out this is related to a change made on the stringLiteral parser regex.
In scala 2.11, the regex was
("\""+"""([^"\p{Cntrl}\\]|\\[\\'"bfnrt]|\\u[a-fA-F0-9]{4})*+"""+"\"").rand now it's("\""+"""([^"\x00-\x1F\x7F\\]|\\[\\'"bfnrt]|\\u[a-fA-F0-9]{4})*"""+"\"").r.The commit that changed the regex is 98737a2#diff-bce6263cece0f67933d12d2f709294696de6c553a335a8123819f0f97aa6587bL52.
The PR description states:
We also removed an invalid (and useless) + at the end of the regexp.I'm not sure to get why the
+is invalid. Can someone give me more details?The text was updated successfully, but these errors were encountered: