marcellperger1 / mathexprcalculatorjava Goto Github PK

Add support for - as a prefix operator (e.g. -(1+2)). There is currently support for it but only as a part of a literal.
So currently this is allowed:

-1 + 2
2--1
4*-2*(-1/-2)

And this is not:

-(1+1)
--2*2

And this is interpreted incorrectly:

-1**2  # Gives 1.0 ((-1)**2), should give -1.0 (-(1**2))

So we need to:

• Add code for the prefix operator - (** < precedence < */)
• TODO: need to add some special cases to ensure that 2**-1 and 2**-3**-2. Python does this using:

  prefixop = '-' power | '+' power | ...
  power = primary '**' prefixop
  primary = ... | '(' ... ')' | ...
  

We need to figure out how to do the exception handling nicely and consistently.

Originally posted by @MarcellPerger1 in #2 (comment)

Add a CLI something like this:

$ mathexpr '2. + 2.3 * 1.8 ** 2 / .9'
20.28

with extra options like rounding (-R?), interactive (-i)

Add an interactive mode/shell like this:

>? 2. + 2.3 * 1.8 ** 2 / .9
10.28

Maybe round the result to 12 sf to avoid FP issues.

Add the MIT license

Upload coverage output to github pages to make it easier to view where the missed lines are.
The output directory for JaCoCo coverage is target/site/jacoco.

Potential problems:

• How to keep different PRs separate?
• Use a workflow or a gh-pages branch?