{"id":186721,"date":"2011-08-30T00:00:00","date_gmt":"2011-09-02T20:25:42","guid":{"rendered":"https:\/\/www.microsoft.com\/en-us\/research\/msr-research-item\/blame-for-all\/"},"modified":"2016-08-22T11:30:32","modified_gmt":"2016-08-22T18:30:32","slug":"blame-for-all","status":"publish","type":"msr-video","link":"https:\/\/www.microsoft.com\/en-us\/research\/video\/blame-for-all\/","title":{"rendered":"Blame for All"},"content":{"rendered":"<div class=\"asset-content\">\n<p>Several programming languages now integrate static and dynamic typing, including C#4.0, Perl 6, and Racket (formerly PLT Scheme), and the research languages Sage and Thorn. However, an important open question remains, which is how to add parametric polymorphism to languages that combine static and dynamic typing.  We present a system that permits a value of dynamic type to be cast to a polymorphic type and vice versa, with relational parametricity enforced by dynamic sealing.  Our system includes a notion of blame, which allows us to show that when casting between a more-precise type and a less-precise type, any failure are due to the less-precisely-typed portion of the program. We also show that a cast from a subtype to its supertype cannot fail.  A `Jack of all Trades&#8217; theorem ensures that our method of mapping polymorphism into a dynamic language is sound.   (Joint work with Amal Ahmed, Robby Findler, and Jeremy Siek.)<\/p>\n<\/div>\n<p><!-- .asset-content --><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Several programming languages now integrate static and dynamic typing, including C#4.0, Perl 6, and Racket (formerly PLT Scheme), and the research languages Sage and Thorn. However, an important open question remains, which is how to add parametric polymorphism to languages that combine static and dynamic typing. We present a system that permits a value of [&hellip;]<\/p>\n","protected":false},"featured_media":196349,"template":"","meta":{"msr-url-field":"","msr-podcast-episode":"","msrModifiedDate":"","msrModifiedDateEnabled":false,"ep_exclude_from_search":false,"footnotes":""},"research-area":[],"msr-video-type":[],"msr-locale":[268875],"msr-impact-theme":[],"msr-pillar":[],"class_list":["post-186721","msr-video","type-msr-video","status-publish","has-post-thumbnail","hentry","msr-locale-en_us"],"msr_download_urls":"","msr_external_url":"https:\/\/youtu.be\/8s7GEvzgr3E","msr_secondary_video_url":"","msr_video_file":"","_links":{"self":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-video\/186721"}],"collection":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-video"}],"about":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/types\/msr-video"}],"version-history":[{"count":0,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-video\/186721\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/media\/196349"}],"wp:attachment":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/media?parent=186721"}],"wp:term":[{"taxonomy":"msr-research-area","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/research-area?post=186721"},{"taxonomy":"msr-video-type","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-video-type?post=186721"},{"taxonomy":"msr-locale","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-locale?post=186721"},{"taxonomy":"msr-impact-theme","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-impact-theme?post=186721"},{"taxonomy":"msr-pillar","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-pillar?post=186721"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}