alibaba/QLExpress

QLExpress3 历史问题修复

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#185 opened on Mar 18, 2022

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 (2 comments) (0 reactions) (0 assignees)Java (4,457 stars) (1,113 forks)batch import
help wanted

Description

QLExpress3 积攒了比较多的历史问题，这里列举额如下：

  • 高精度计算溢出问题（除了这里列举的场景外还有很多有问题的场景，需要一一排查下）
String evalExpress = "a*2";

final ExpressRunner runner = new ExpressRunner(true, true);

DefaultContext<String, Object> nameMap = new DefaultContext<String, Object>();

nameMap.put("a", new BigDecimal(Long.MAX_VALUE));

// 结果为 -2
Object obj = runner.execute(evalExpress, nameMap, null, false, true);
  • 注释解析问题

参考 #337

Contributor guide

Tech stack
java
Domain
backenddeveloper experienceperformance
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
JavaBigDecimalexpression parsing
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
Investigate the high precision calculation overflow in the arithmetic evaluation logic. The issue provides an example with BigDecimal multiplication overflow. Check file OperateData.java or similar classes handling numeric operations. Also examine issue #337 for the comment parsing bug, which may involve the lexer or parser. Propose fixes that handle overflow by checking for result overflow or using appropriate arithmetic.