Skip to content

Inaccurate/misleading description of max in operators module (wrt. NaN comparison) #82

Description

@abonie

Not sure if this is an error in documentation or purposeful omission, or perhaps a bug in fsharp.

Here max is described as

Maximum based on generic comparison

And here compare is described as

Generic comparison.

However, even though they kind of boil down to the same thing in implementation for most types, they do not specifically for floating point numbers. Moreover, if one defines a max function with compare, for example like this:

let max2 x y = if compare x y < 0 then y else x

Then max2 behaves differently than max with respect to NaN, e.g.:

> max2 1. nan;;
val it: float = 1.0

> max2 nan 1.;;
val it: float = 1.0

whereas

> max nan 1.;;
val it: float = nan

> max 1. nan;;
val it: float = nan

If this discrepancy in behavior is expected, then perhaps it should be documented?

Activity

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    Type

    No type

    Projects

    No projects

      Milestone

      No milestone

      Relationships

      None yet

      Development

      No branches or pull requests

      Issue actions