Add record support to constants

[Shan1024]

Purpose

This PR adds support to define record constants.

Resolves #14877

Sample usages

Simple constant map declarations

using records -

type BR1 record {|
    boolean key1;
    boolean key2;
|};

const BR1 br1 = { key1: true, key2: false };

using anonymous records -

const record {| boolean key1; boolean key2; |} br1 = { key1: true, key2: false };

Nested constant map declaration

using records -

type BR1 record {|
    boolean key1;
    boolean key2;
|};

type BR2 record {|
    boolean key3;
    boolean key4;
|};

type BR3 record {|
    BR1 key5;
    BR2 key6;
    anydata...;
|};

type BR4 record {|
    boolean key8;
    boolean key9;
|};

const BR4 br4 = { key8: true, key9: false };

const BR3 br3 = { key5: br1, key6: br2, key7: br4 };
const BR1 br1 = { key1: true, key2: false };
const BR2 br2 = { key3: false, key4: true };

using anonymous record -

const record {| boolean key8; boolean key9; |} br4 = { key8: true, key9: false };

const record {| record {| boolean key1; boolean key2; |} key5; record {| boolean key3; boolean key4; |} key6; anydata...; |} br3 = { key5: br1, key6: br2, key7: br4 };
const record {| boolean key1; boolean key2; |} br1 = { key1: true, key2: false };
const record {| boolean key3; boolean key4; |} br2 = { key3: false, key4: true };

Constant references in maps

const v = "v"; 
const record {| string...; |} r = { k: v };

Simple constant map key references in maps

const record {| string...; |} r1 = { k: "v" };
const record {| string...; |} r2 = { k: r1.k };

Chained constant map key references in maps

const record {| string...; |} r1 = { k1: "v" };
const const record {| record {| string...; |}...; |} r2 = { k2: r1 };

const record {| string...; |} r3 = { k: r2.k2.k1 };

Equality checks

const record {| boolean...; |} br1 = { key1: true };
const record {| boolean...; |} br2 = { key2: false };
const record {| record {| boolean...; |}...; |} br3 = { key3: br1, key4: br2 };

const record {| boolean...; |} br1_new = { key1: true };
const record {| boolean...; |} br2_new = { key2: false };
const record {| record {| boolean...; |}...; |} br3_new = { key3: br1_new, key4: br2_new };

const record {| record {| boolean...; |}...; |} br7 = { key3: { key1: true }, key2: { key4: false } };
const record {| record {| boolean...; |}...; |} br8 = { key3: { key1: true }, key2: { key4: false } };

// -----------------------------------------------------------

br1 == br1; // true
br1 == br1_new; // true

br1 === br1; // true
br1 === br1_new; // false

// -----------------------------------------------------------

br3 == br3; // true
br3 == br3_new; // true

br3 === br3; // true
br3 === br3_new; // false

// -----------------------------------------------------------

br3.key3 == br3.key3; // true
br3.key3 == br3_new.key3; // true

br3.key3 === br1; // true
br3.key3 === br3_new.key3; // false

// -----------------------------------------------------------

br7.key3 == br7.key3; // true
br7.key3 == br1; // true

br7.key3 === br7.key3; // true
br7.key3 === br1; // false

// -----------------------------------------------------------

br7 == br8; // true
br7 === br8; // false

br7.key3 == br8.key3; // true
br7.key3 === br8.key3; // false

Usages which will result in panics

record {| record {| string...; |}...; |} sr10 = { sr10k: sr11 };
const record {| string...; |} sr11 = { sr11k: "sr11v" };

function updateNestedConstantStringRecordValueWithExistingKey() {
    sr10.sr10k.sr11k = "sr11nv"; // panic
}

function updateNestedConstantStringRecordValueWithNewKey() {
    sr10.sr10k.newKey = "newValue"; // panic
}

function updateReturnedConstantStringRecordWithExistingKey() {
    record {| string...; |} m = getStringRecord();
    m.sr11k = "sr11kn"; // panic
}

function updateReturnedConstantStringRecord2WithNewKey() {
    record {| string...; |} m = getStringRecord();
    m.newKey = "newValue"; // panic
}

function getStringRecord() returns record {| string...; |} {
    return sr11;
}

// -----------------------------------------------------------

record {| string...; |}[] sa1 = [sr11];

function updateConstantStringRecordValueInArrayWithExistingKey() {
    sa1[0].sr11k = "sr11nv"; // panic
}

function updateConstantStringRecordValueInArrayWithNewKey() {
    sa1[0].newKey = "newValue"; // panic
}

function getConstantStringRecordValueInArray() returns string {
    return sa1[0].sr11k;
}

Check List

• Read the Contributing Guide
• Required Balo version update
• Updated Change Log
• Checked Tooling Support (#)
• Added necessary tests
  • Unit Tests
  • Spec Conformance Tests
  • Integration Tests
  • Ballerina By Example Tests
• Increased Test Coverage
• Added necessary documentation
  • API documentation
  • Module documentation in Module.md files
  • Ballerina By Examples

[codecov-io]

Codecov Report

Merging #15231 into master will increase coverage by 0.19%.
The diff coverage is 0%.

@@             Coverage Diff              @@
##             master   #15231      +/-   ##
============================================
+ Coverage     23.03%   23.23%   +0.19%     
- Complexity     4995     5065      +70     
============================================
  Files          1342     1342              
  Lines         67183    67497     +314     
  Branches       9112     9203      +91     
============================================
+ Hits          15477    15680     +203     
- Misses        50004    50079      +75     
- Partials       1702     1738      +36

Impacted Files	Coverage Δ	Complexity Δ
.../ballerinalang/util/diagnostic/DiagnosticCode.java	0% <0%> (ø)	0 <0> (ø)	⬇️
...iler/semantics/analyzer/ConstantValueResolver.java	0% <0%> (ø)	0 <0> (ø)	⬇️
.../compiler/semantics/analyzer/SemanticAnalyzer.java	0% <0%> (ø)	0 <0> (ø)	⬇️
...g/wso2/ballerinalang/compiler/desugar/Desugar.java	0% <0%> (ø)	0 <0> (ø)	⬇️
.../ballerinalang/compiler/codegen/CodeGenerator.java	0% <0%> (ø)	0 <0> (ø)	⬇️
...alang/compiler/semantics/analyzer/SymbolEnter.java	0% <0%> (ø)	0 <0> (ø)	⬇️
...viders/subproviders/ServiceCompletionProvider.java	72.09% <0%> (-19.58%)	9% <0%> (+5%)
...erinalang/langserver/completions/util/Snippet.java	94.31% <0%> (-5.69%)	3% <0%> (ø)
...rg/wso2/ballerinalang/compiler/bir/BIREmitter.java	0% <0%> (ø)	0% <0%> (ø)	⬇️
...va/org/wso2/ballerinalang/compiler/bir/BIRGen.java	0% <0%> (ø)	0% <0%> (ø)	⬇️
... and 9 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 800f8cd...a2c30e8. Read the comment docs.

[Shan1024]

Closing the PR since this might be outdated after 2 months and no one bothered to even check and approve this PR.