expression: refactor functions to build expressions

[lcwangchao]

What problem does this PR solve?

Issue Number: close #50996

We have many functions to build expressions, but it is unclear which we should use for a certain case and some codes in these functions are duplicated. It's better to refactor them to make it clear.

What changed and how does it work?

In this PR, we provide two groups of functions to build expressions.

The first function group is exposed in the package expression and used to build simple expressions. The "simple" means they do not include some special expressions such as subquery. Here we simplified to 3 functions:

• expression.BuildSimpleExpr: build a simple expression from an AST node.
• expression.ParseSimpleExpr: parse a string and then build a simple expression
• expression.EvalSimpleAst: build a simple expression from an AST node and evaluate it directly.

The first group requires limited context and can be used in some places where you do not want to introduce too many dependencies. However, if you need to build some complex expressions like subquery, we should use the second group. The second group is exposed in the package planner/util and can build any expression. However, it requires the full context of a planner. These functions includes:

• util.RewriteAstExprWithPlanCtx: build an expression with the plan context
• util.EvalAstExprWithPlanCtx: evaluates an expression directly with the plan context
• util.ParseExprWithPlanCtx: parse an expression from the string with the plan context

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No need to test

  • I checked and no code files have been changed.

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

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[codecov]

Codecov Report

Merging #50997 (b624542) into master (8988b4c) will increase coverage by 2.1190%.
Report is 1 commits behind head on master.
The diff coverage is 85.0000%.

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #50997        +/-   ##
================================================
+ Coverage   70.5150%   72.6341%   +2.1190%     
================================================
  Files          1467       1467                
  Lines        434890     434896         +6     
================================================
+ Hits         306663     315883      +9220     
+ Misses       108910      99077      -9833     
- Partials      19317      19936       +619     

Flag	Coverage Δ
integration	48.9826% <80.8333%> (?)
unit	70.2855% <80.0000%> (-0.0101%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
dumpling	54.2940% <ø> (ø)
parser	∅ <ø> (∅)
br	51.2177% <100.0000%> (+5.5058%)	⬆️

[YangKeao]

LGTM

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-02-06 02:33:19.744746258 +0000 UTC m=+237725.311516147: ☑️ agreed by lance6716.
• 2024-02-06 07:44:00.347876263 +0000 UTC m=+256365.914646169: ☑️ agreed by YangKeao.

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: lance6716, mjonss, XuHuaiyu, YangKeao, zimulala

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• OWNERS [XuHuaiyu,YangKeao,lance6716,mjonss,zimulala]
• br/pkg/lightning/OWNERS [lance6716]
• pkg/ddl/OWNERS [zimulala]
• pkg/executor/importer/OWNERS [lance6716]
• pkg/expression/OWNERS [XuHuaiyu]
• pkg/infoschema/OWNERS [zimulala]
• pkg/table/OWNERS [zimulala]

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