PowerLauncher calculator should be customizable

[leduyquang753]

Summary of the new feature/enhancement

Currently the calculator plugin only accepts expressions in the US format. For users using other formats (such as the comma for decimal separation and the dot for multiplication, yes the full stop), the calculator should provide necessary customization options.

Proposed technical implementation details

• Customize Mages or use/make a different engine that allows customizations.
• Add the customizations to the Calculator section of PowerLauncher's settings page.
• The customizations include: decimal and thousand separators, multiplication sign (for displaying .10^ in the result), angle unit for trigonometric functions,...
• The separators can be customized by textboxes or more manageable radio buttons/combo boxes.
• If there is a conflict (for example both the multiplication sign and the decimal separator are the dot), either the settings are automatically fixed or the app simply doesn't let the user set so (by graying out, but less preferred because the user might not be able to swap the signs).

[Jay-o-Way]

A normal dot (full stop) should not be used in stead of multiplication. In typing the asterisk * is normal and in writing you may use the middle•dot. There is already enough trouble with the locales: Using a comma or full stop as decimal point.

Only valid comment is that the degree sign ° doesn't seem to be supported right now.

[leduyquang753]

A normal dot (full stop) may NEVER be used in stead of multiplication.

The full stop for multiplication is used here in Vietnam, where you can see in all kinds of textbooks for students.

We shouldn't need to go through the trouble of replacing dots with asterisks when for example, we copy-paste an expression.

In case you missed, here is what I already said in implementation details:

If there is a conflict (for example both the multiplication sign and the decimal separator are the dot), either the settings are automatically fixed or the app simply doesn't let the user set so (by graying out).

It's in our own control to not rely on the computer's localization settings and format the numbers according to the app's settings chosen. To prevent inconvenience to the user, we can check for the computer's localization in the first run of the app and initialize the options based on that.

[jyuwono]

For the comma as decimal separation, we have another issue tracking it (see #3367)

[crutkas]

I think a good thing we need to do here is come up with a ton of unit tests that handle appropriate regional preferences. Preferred route is adopting the calculator engine which should do this for us for free

[crutkas]

@leduyquang753 how does the windows calculator deal with this, does it handle your preferred options by default?

[leduyquang753]

It currently only handles the decimal separator customization, per Windows' localization settings. I have also opened an issue there to allow different forms of notation as well: microsoft/calculator#1251

[crutkas]

https://mathparser.org/
https://www.nuget.org/packages/MathParser.org-mXparser/

[crutkas]

Going to track this in #3367