calc82: Devlog #3 10/07/2026

calc82: because calculators are for everyone

Oh dear, looks like I lost 4 hours of counted time in the last devlog… let’s try to make this one a bit shorter!

This devlog follows the implementation of the other inline functions of the calculator:

🌟 New functionality summary

• inverse and hyperbolic trig
• arbitrary roots
• absolute value
• percent
• random numbers: Ran and RanInt
• scientific notation: *10^x / E
• combinatorics: nPr and nCr
• variables (not yet adjustable)

📋 Implementation details

Implementing most of this functionality followed the same general steps:

1. identify
2. implement
3. test.

As I undertook this process. other dependent requirements popped up - such as the implementation of multivariable functions, which in turn required the expansion of the tokeniser and parser.

Also, I implemented degrees, radians, and gradians modes into the calculator, and the associated functions (as postfix expressions - e.g. sin(30d) for degrees).

🗄️ decimal.js changes

Finally, I applied some further changes to decimal.js.:

• Rounding now depends on the closeness of the output to a known value, rather than the input, reducing unnecessary rounding
• Near-decimal values close to 0, 0.25, 0.5, 0.75 and 1 are now caught.

🗒️ Notes:

Remembering that Javascript is weird
NaN === NaN is FALSE! Spent a good 10 minutes figuring this one out. The solution was to use isNaN().

Fixing negative-base powers:
(-8)^(1/3) should equal 2 but returns NaN
Fixed by taking the denominator from the output of a decimal.js toFraction() function, which attempts to create a rational fraction. This overcomes the tiny precision loss and evaluates the function correctly

📈 Next steps

Immediate:

• Add fractional I/O
• Implement polar/rectangualr conversion

Medium:

• Create algebraic display functionality
• Multi-line calculation (Ans) and setting variables

Long-term:

• Build UI
• Ship :)

This has been a bit of a shorter devlog. But I’m still proud of what I achieved! Thanks so much for reading. If you have any suggestions, please leave me a comment. Take care