<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Jan 24, 2015, at 1:43 AM, Matthew Butterick wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: 'Lucida Grande'; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; ">FWIW, Sam's point that one can't expect every untyped program to work without modification is entirely fair. </span></blockquote><div><br></div><div>Correct. </div><div><br></div><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: 'Lucida Grande'; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; ">But Konrad's point is also fair: if a function like `append` or `hash` works differently in TR, then it is, for practical purposes, not the same function, even if it relies on the same code. </span></blockquote><div><br></div><div>This statement is too coarse. There are at least two senses in which a TR function f is distinct from an R function: </div><div><br></div><div>1. f's type restricts the usability of f to a strict "subset" [in the naive set-theoretic sense]. This is most likely due to a weakness of the type system; the language of "theorems" isn't strong enough to express R's intention w/o making the inference rules unsound. [Unlike in the legal world, In PL arguments of 'typedness' must be about truly-guilty or not-guilty. The rulings are completely impartial and uniform, i.e., totally fair.]</div><div><br></div><div>2. f's type ___changes___ the meaning of the code. (That's also possible but I don't want to fan the argument that Sam and I have about this.) </div><div><br></div><br><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: 'Lucida Grande'; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; ">If it would be superfluous to repeat every TR function in the documentation, it still could be valuable to document some of the major departures from Racket. I mean, I would read that, for sure ;)</span></blockquote></div><br><div><br></div><div>Actually it would not be superfluous. We just don't have the manpower but perhaps it's time to tackle this problem (perhaps in a semi-automated manner). </div><div><br></div><div>-- Matthias</div><div><br></div></body></html>