stdlib_selection: correction of typos and addition of some checks

[jvdp1]

• I corrected some typos in stdlib_selection.md
• I added some checks to ensure that k in select(x, k, kth, letft, right) is within the interval [left: right].

ping @gareth-nx

[gareth-nx]

Thanks for that, looks good.

[awvwgk]

Looks good to me

[gareth-nx]

Thanks!

[ivan-pi]

The error message now doesn't mention the condition that k be in the interval [l, r]. Maybe breaking into two if blocks would make it easier on the eye. But I don't have strong feelings about this.

[gareth-nx]

I just noticed another minor issue in stdlib_selection.md. At line 26, there should be a new line before * select.

At the moment you can see we are missing a newline in the html view, just under the "Overview of the module" section. Interestingly this formatting issue doesn't occur with the github markdown view.

If you can add a newline as part of this pull request, great. Otherwise I can make a pull request later.

[jvdp1]

The error message now doesn't mention the condition that k be in the interval [l, r]. Maybe breaking into two if blocks would make it easier on the eye. But I don't have strong feelings about this.

Thank you @ivan-pi . I modified the lines as follows:

error stop "select must have 1 <= left <= k <= right <= size(a)"; 

[jvdp1]

I just noticed another minor issue in stdlib_selection.md. At line 26, there should be a new line before * select.

At the moment you can see we are missing a newline in the html view, just under the "Overview of the module" section. Interestingly this formatting issue doesn't occur with the github markdown view.

If you can add a newline as part of this pull request, great. Otherwise I can make a pull request later.

Done. Thank you @gareth-nx

[gareth-nx]

@jvdp1 In case you make further changes here, could you please also add a suitable ford comment at the top of the stdlib_selection.fypp, such as:

!! Quickly find the k-th smallest value of an array, or the index of the k-th smallest value. 

This statement will then appear on the stdlib module html page: https://stdlib.fortran-lang.org/lists/modules.html

Thanks.

[gareth-nx]

Thanks

[jvdp1]

Mainly fixing typos and links for FORD. Thank you to the reviewers.