Re: Dimensionality Checking (Ada 20XX)

["Nick Roberts" <nickroberts@adaos.worldonline.co.uk>]

Dmitry, you're an absolute gem! It's worth a thousand "well I reckon"s to
actually produce the proof.

I have been doing a bit of reading up on dimensionsal analysis, and from
what I can tell from 'the texts', any and all exponentiations and logarithms
are dimensionless, and their arguments must be dimensionless (of dimensions
all 0).

So, the expression Exp(X) is dimensionless, and X must be (checked to be)
dimensionless. Ditto for Log(X).

The same is also true for the trigonometric functions. I recall someone
posting in this thread suggesting, in effect, that the same is also true for
square root; I'd like this confirmed.

So, may I first apologise for the confusion I seem to sow in my wake like a
talented double-glazing salesman. Secondly, I suppose the standard package
Ada.Numerics.Generic_Elementary_Functions could and should check (upon
instantiation) that the generic parameter type Float_Type is either
dimensionless or not unit-specific. Am I correct in assuming that the Cycle
parameter must always be dimensionless?

I have accepted the idea of units being applicable to floating point types,
as well as fixed point types, with the concern that unit-specific floating
point types are (more) liable to abuse. Am I right that
Ada.Numerics.Float_Random.Uniformly_Distributed should not be unit-specific?

As a slightly separate issue, is there any merit in the idea of adding
standard packages that provide Log, Exp, sin, Cos, Tan, etc. for fixed point
types?

--
Best wishes,
Nick Roberts