[Task]: Revamp cloneWithType and fromJsonWithType

[Nadeeshan96]

Description

$title

Describe your task(s)

• [Task]: Bring fromJsonWithType and cloneWithType into a common implementation #39162
• [Bug]: Conversion of a value to the table, regexp:RegExp types in cloneWithType is erroneous #38716
• [Bug]: Cannot convert a value to the xml type using cloneWithType #38715
• [Bug]: Fix spec deviations in handling ambiguities in cloneWithType #39168
• Provide a runtime API to clone a value to a type #35141
• [Bug]: Table value conversion is failing for union target type #39385
• [Bug]: CloneWithType gives unexpected error when converting table to any data #39383
• [Improvement]: Support converting to Type Reference types in fromJsonWithType and cloneWithType #38717
• [Bug]: Cannot convert possible string values to xml subtypes #39610
• [Bug]: cloneWithType is not working with TypeReferenceType  #39907

Related area

-> Runtime

Related issue(s) (optional)

No response

Suggested label(s) (optional)

No response

Suggested assignee(s) (optional)

No response

[Nadeeshan96]

Tried to do a performance improvement in the TypeConverter.getConvertibleType type method by saving the resolved convertible types in a hash map. Then compared the performance before and after the change.

First ran the langlib value tests in a large loop and measured the time and memory using Jprofiler.

	Before	After
Peak memory usage	236.7 MB	247.6 MB (+4.6%)
Total all objects live memory	250 MB	185 MB (-26%)
Total time	32 s	34 s (+6.25%)
convert method total time	14.4 s	16.57 s (+15.07%)
Peak process CPU load	37.56%	33.27%

Then converted a large json to a record in a large loop and measured the time and memory using Jprofiler.

	Before	After
Peak memory usage	126.4 MB	212.5 MB (+68.12%)
Total all objects live memory	195 MB	75.7 MB (-61.18%)
Total time	11 s	8 s (-27.27%)
convert method total time	9.303 s	7.304 s (-21.49%)
Peak process CPU load	26.7%	27%

Due to the above results, decided not to do the above change.

[Nadeeshan96]

Improve error message given in the failure of type conversion when the target type is a union

public function main() {
    foo();
}

type NumberArray int[]|float[];
type StringArray string[]|string:Char[];
type NumberOrStringArray NumberArray|StringArray;

type RecordWithArrayAsAField record {|
    NumberOrStringArray arr;
|};

type RecordWithNumberArrayAsAField record {|
    NumberArray arr;
|};

function foo() {
    json j = {"arr": [1,1.2,"a","aa"]};
    RecordWithArrayAsAField|RecordWithNumberArrayAsAField jCloned = checkpanic j.cloneWithType();
}

For example for the above code the error message is given as follows with all the errors together, which seems infeasible.

Running executable

error: {ballerina/lang.value}ConversionError {"message":"'map<json>' value cannot be converted to '(RecordWithArrayAsAField|RecordWithNumberArrayAsAField)': 
                array element 'arr[2]' should be of type 'int', found '"a"'
                array element 'arr[3]' should be of type 'int', found '"aa"'
                array element 'arr[2]' should be of type 'float', found '"a"'
                array element 'arr[3]' should be of type 'float', found '"aa"'
                array element 'arr[0]' should be of type 'string', found '1'
                array element 'arr[1]' should be of type 'string', found '1.2'
                array element 'arr[0]' should be of type 'lang.string:Char', found '1'
                array element 'arr[1]' should be of type 'lang.string:Char', found '1.2'
                array element 'arr[3]' should be of type 'lang.string:Char', found '"aa"'
                array element 'arr[2]' should be of type 'int', found '"a"'
                array element 'arr[3]' should be of type 'int', found '"aa"'
                array element 'arr[2]' should be of type 'float', found '"a"'
                array element 'arr[3]' should be of type 'float', found '"aa"'"}
        at ballerina.lang.value.0:cloneWithType(value.bal:114)
           temp:foo(temp.bal:23)
           temp:main(temp.bal:6)

This can be improved for something like below.

Running executable

error: {ballerina/lang.value}ConversionError {"message":"'map<json>' value cannot be converted to '(RecordWithArrayAsAField|RecordWithNumberArrayAsAField)': 
                    array element 'arr[2]' should be of type 'int', found '"a"'
                    array element 'arr[3]' should be of type 'int', found '"aa"'
                  or
                    array element 'arr[2]' should be of type 'float', found '"a"'
                    array element 'arr[3]' should be of type 'float', found '"aa"'
                  or
                    array element 'arr[0]' should be of type 'string', found '1'
                    array element 'arr[1]' should be of type 'string', found '1.2'
                  or
                    array element 'arr[0]' should be of type 'lang.string:Char', found '1'
                    array element 'arr[1]' should be of type 'lang.string:Char', found '1.2'
                    array element 'arr[3]' should be of type 'lang.string:Char', found '"aa"'
                or
                    array element 'arr[2]' should be of type 'int', found '"a"'
                    array element 'arr[3]' should be of type 'int', found '"aa"'
                  or
                    array element 'arr[2]' should be of type 'float', found '"a"'
                    array element 'arr[3]' should be of type 'float', found '"aa"'"}
        at ballerina.lang.value.0:cloneWithType(value.bal:114)
           temp:foo(temp.bal:23)
           temp:main(temp.bal:6)

[Nadeeshan96]

Another bug:

type JsonUnion xml|json;
type AnyDataUnion int|anydata;

public function main() {
    xml a  = xml `<a>1</a>`;
    // JsonUnion & readonly j = checkpanic a.cloneWithType();

    AnyDataUnion & readonly jj = checkpanic a.cloneWithType();
}

gives

error: {ballerina}TypeCastError {"message":"incompatible types: 'lang.xml:Element' cannot be cast to 'error'"}
        at jsonUnuion:main(jsonUnuion.bal:8)

[Nadeeshan96]

#39217 (comment) and #39217 (comment) is fixed with #39212.

[Nadeeshan96]

Closing the issue because the task is done.