Helix Calc is a simple Reverse Polish Notation calculator.

It's written in Rust, using Ratatui for the cross-platform interface and bigdecimal-rs for the internal operations.

The name is inspired by Helix Editor, and the functionality by the venerable GNU dc.

This is a toy app that fulfills my personal needs, but I'm open to PR :)

Operations

Operators manipulate the stack of values [S1, S2, ...]:

• +, -, *, / : perform the arithmetic operation on S2 and S1.
• % : compute the modulo of S2 divided by S1.
• ^ : raise S2 to the power of S1.
• P : pop S1 off the stack.
• d : duplicate S1.
• v : compute the square root of S1.
• k : pop S1 and use it to set the precision.
• o : pop S1 and use it to set the output base (2–36).
• r : swap S1 and S2.
• u : undo the last operation.
• U : redo the last undone operation.
• s : pop S1 and save it to a named register (prompts for a key).
• l : load a named register onto the stack (prompts for a key).
• c : clear the stack.
• C : clear the registers.
• n : reset precision and output base.
• y : rotate stack forward (S1→S2→S3→…→S1).
• Y : rotate stack backward (S1→…→S3→S2→S1).
• ' : toggle decimal separator.
• [Up]: edit S1.

Negative numbers

Two options to enter them:

• Type them as _123.
• Type them as 123- (careful, no space).

Limitations

By default, BigDecimal is compiled with a max precision of 100 digits: beyond that size, decimal places will be dropped, even if the integer part can handle much larger numbers.