Le 14/08/2012 04:16, Allen Wirfs-Brock a écrit : > check out the current ES66 spec. draft. Based upon discussions at the > March TC39 meeting hypot2 was eliminated and an optional third > argument as added to hypot. Quoting relevant part of the March meeting notes [1]: > Discussion of hypot, hypot2. > hypot is the square root of the sum of squares and takes either two or > three arguments. > hypot2 is the sum of squares and takes either two or three arguments. > Waldemar: How is hypot2 better than just doing x*x + y*y? > Luke: It's just ergonomics. > General reluctance about the hypot2 name because it looks like the 2 > means two arguments (as in atan2). Some debate about other function > names (hypotSq? sumOfSquares?). > MarkM: How is hypot better than sqrt(x*x + y*y)? > It's potentially more efficient and more accurate. It is widespread > in numeric libraries. > Consensus: hypot will support just two or three arguments. hypot2 dropped. Consensus here indeed.
> Waldemar, MarkM: Why not one or zero arguments? It would be 0 for > zero arguments and abs for one argument. > Allen, DaveH: If you pass one argument to hypot, you'll get NaN. > Luke: It's not variadic. > Waldemar: Why isn't it variadic? > Luke: 2 or 3 is the 99% use case. > Waldemar: 2 or 3 arguments is the 99% use case for max. > Waldemar: If it's not variadic and takes only 2 or 3 arguments, > you'll get silent mistakes. If you pass in four arguments, you'll get > the hypot of the first three, and the last one will be silently > ignored. That's bad. I agree and it seems to be unadressed by the decision in the consensus, is it? If it's decided that hypot should only accept at most 3 arguments, then, passing 4 or more args should return NaN (instead of making people hate JavaScript more because of error hiding). I however still believe having hypot variadic is more interesting, though. > Luke: Will go back to the experts to explore implementing variadic hypot. Who/what does "the experts" refer to here? > Note that the new function names such as hypot are generally selected > to match the names from widely used c > libraries: > https://docs.google.com/spreadsheet/ccc?key=0Ak51JfLL8QLYdDBVcFZaMXhlY2d2RnM0TDVxLWlua3c&hl=en#gid=0 > I certainly missed the discussion where this choice was made, but does C-matching matters? For Math functions, I would tend to favor function names math folks are used to, like the ones in Matlab (which I don't know at all, maybe they map the C ones too). Is the proportion of people who come to JavaScript from C using math libraries (as opposed to people coming to JavaScript with any other background) big enough to consider familiarity with C function names a decisive argument for JavaScript function naming? David [1] https://mail.mozilla.org/pipermail/es-discuss/2012-March/021919.html _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
