Create select with comma macro to support negative number

[24seconds]

Description

For the better readability, gluesql uses select! macro.
But there is a nit problem. It can not handle consecutive negative numbers. That is why there are some workaround code - for example, parse_i64

Below code is the one example of workaound.

test!(
    Ok(select!(
        field_one          | field_two
        I64                |    I64;
        1                  parse_i64("-1");
        parse_i64("-2")    2;
        3                  3;
        parse_i64("-4")    parse_i64("-4")
    )),
    "SELECT field_one, field_two FROM Item"
);

This is because macro rule can not handle consecutive negative numbers with whitespace separator. Here is the playground link

Suggestion

To solve this problem, It is good to use clear separator such as comma or bar instead of whitespace.
So I made a select_with_comma macro.

[coveralls]

Pull Request Test Coverage Report for Build 2722269177

• 27 of 27 (100.0%) changed or added relevant lines in 5 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.03%) to 97.81%

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Totals
Change from base Build 2698746514:	0.03%
Covered Lines:	28769
Relevant Lines:	29413

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💛 - Coveralls

[24seconds]

Oops. Thank you @ever0de . Let me change the separator as |

[24seconds]

It seems | is not good to be used as separator. I got this error.

[24seconds]

Let me try to find the workaround as much as possible I can. Until that, let me change this pr as draft

[ever0de]

We share some experimental results...

1. If you change it to literal, the | delimiter works.
   1.1 Changing to literal disables ToOwned or closure.
2. expr only works as a delimiter for =>, ,, and ;.

cc. @panarch

[24seconds]

conclusion

match expression: Change expr -> literal
separator: comma -> bar

Type converting: Implement trait - convert row value type(literal) to column value type
Reason of needing type converting trait implementation -> Date time, static lifetime str could be problematic. Literal is primitive type. We will pass our code as literal in macro. Therefore, in the macro we need to convert literals to gluesql types so that we can run (or execute) the code with gluesql types. Therefore we should implement converting logic - from literal to gluesql type

As-is

test!(
    Ok(select!(
        field_one          | field_two
        I64                |    I64;
        1                  parse_i64("-1");
        parse_i64("-2")    2;
        3                  3;
        parse_i64("-4")    parse_i64("-4")
    )),
    "SELECT field_one, field_two FROM Item"
);

To-be

test!(
    Ok(select!(
        field_one          | field_two
        I64                |    I64;
        1                  |   -1;
        2                  |    2;
        3                  |    3;
        -4                 |   -4
    )),
    "SELECT field_one, field_two FROM Item"
);

Note

.to_owned, Date could be removed in the macro usage side code base

@ever0de ?