Allow simple maths expressions in the Ingridients editor > Quanitity

[BlenderDefender]

First Check

• I used the GitHub search to find a similar requests and didn't find it.
• Checked the tasks tagged issues and verified my feature is not covered

Please provide a concise description of the problem that would be addressed by this feature.

When editing recipes, I'd often like to use maths expressions like addition, multiplication, division or subtraction for updating the quantity of an ingredient.
Two scenarios I've had, where this would be helpful:

1. I've tried out a recipe and now I'm updating it according to my experience. I've used about 50 grams more of one ingredient and only 90% of another ingredient
2. Scaling a recipe down after scraping it. A source defaults to a recipe yield of 6 servings, I'd like to scale it down to 2 servings. Sure, I could use the scale down factor in the recipe display page, but I'd like to have it saved as a scaled down version.

Please provide a concise description of the feature that would resolve your issue.

Allowing simple maths expressions in the quantity field, using a library like math-expression-evaluator, would resolve my issue.
Feature Request Mockup.webm

Please consider and list out some caveats or tradeoffs made in your design decision

• From what I've found out, having a type "number" input doesn't work with this feature, so the quantity input would be turned into a regular text field
• This would add another dependency (math-expression-evaluator: 68 kB) to Mealie, unless someone is willing to write a maths parser for this feature request.

Additional Information

• If this is accepted I'm willing to submit a PR to provide this feature
• If this is accepted I'm willing to help maintain this feature
• I'm willing to sponsor/pay a developer to do this work

[indykoning]

Personally i am very interested in scenario 2.
I live alone and sometimes with 2 people.
Mostly all recipes are made for 4 or 6 people. Scaling down is possible but i have to do it every time, and i understand how it works. But my partner does not.

Even if it's only the scaling option being available during editing the ingredients i'll be happy as i'll be able to scale there, and setting the servings when viewing the recipe will make sense

[irnutsmurt]

I'd gladly drop a few dollars to implement this feature so I can adjust the recipe portions on the fly like doubling, or halving the servings.

[michael-genson]

You can adjust the entire recipe on the fly if your ingredients are parsed into quantities