Fix backslash escaping in Hive string literals for Trino conversion#583
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Fix backslash escaping in Hive string literals for Trino conversion#583
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In Hive SQL, backslash is an escape character in string literals: '\\d' represents the string \d (single backslash + d). Previously, Coral only unescaped \' and \" but not \\, causing double backslashes to be preserved in the internal representation. When outputting to Trino SQL (where backslash has no special meaning), the extra backslash produced incorrect regex patterns in REGEXP_LIKE calls. Renamed removeBackslashBeforeQuotes to unescapeHiveStringLiteral and extended it to also handle \\ -> \ escape sequences. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- testRlikeBackslashEscapingWithColumn: column reference with regex - testRegexpBackslashEscaping: REGEXP synonym with \w pattern - testStringLiteralWithEscapedBackslash: general string literal escaping
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Summary
\'and\"but not\\. In Hive SQL,\\is an escape sequence for a single backslash. Trino SQL does not use backslash escaping, so the preserved double backslash caused incorrect regex patterns inREGEXP_LIKEcalls.'\\d{4}'(string value\d{4}) was output as Trino'\\d{4}'(string value\\d{4}— wrong). Now correctly outputs'\d{4}'.removeBackslashBeforeQuotestounescapeHiveStringLiteraland extended the regex to handle\\→\Testing Done
HiveToTrinoConverterTest.testRlikeBackslashEscapingverifying date regex pattern conversion./gradlew clean buildpasses (547 tasks, all tests green including existing backslash-related tests)