{"id":1192,"date":"2012-09-13T09:24:41","date_gmt":"2012-09-13T09:24:41","guid":{"rendered":"http:\/\/www.navision-blog.de\/?p=1192"},"modified":"2012-09-25T10:13:44","modified_gmt":"2012-09-25T10:13:44","slug":"graph-type-providers-in-fsharpx","status":"publish","type":"post","link":"http:\/\/www.navision-blog.de\/blog\/2012\/09\/13\/graph-type-providers-in-fsharpx\/","title":{"rendered":"Graph type providers in FSharpx"},"content":{"rendered":"

After the official Visual Studio 2012 launch yesterday I think it\u2019s a good idea to announce two new type providers which are based on the DGMLTypeProvider from the F# 3.0 Sample Pack<\/a>.<\/p>\n

Synchronous and asynchronous state machine<\/h5>\n

The first one is only a small extension to the DGMLTypeProvider by Tao<\/a>. which allows to generate state machines from DGML<\/a> files. The extension is simply that you can choose between the original async state machine and a synchronous version, which allows easier testing.<\/p>\n

\"image\"<\/a><\/p>\n

If you want the async version, which performs all state transitions asynchronously, you only have to write AsyncStateMachine<\/strong> instead of StateMachine.<\/strong><\/p>\n

State machine as a network of types<\/h5>\n

The generated state machine performs only valid state transitions, but we can go one step further and model the state transitions as compile time restrictions:<\/p>\n

\"image\"<\/a><\/p>\n

As you can see the compiler knows that we are in State2 and allows only the transitions to State3 and State4.<\/p>\n

If you write labels on the edges of the graph the type provider will generate the method names based on the edge label. In the following sample I\u2019ve created a small finite-state machine which allows to check a binary number if it has an even or odd number of zeros:<\/p>\n

\"image\"<\/a><\/p>\n

As you can see in this case the compiler has already calculated that 10100<\/em> has an odd number of zeros \u2013 no need to run the test \"Zwinkerndes.<\/p>\n

This stuff is already part of the FSharpx.TypeProviders.Graph<\/a> package on nuget so please check it out and give feedback.<\/p>\n","protected":false},"excerpt":{"rendered":"

After the official Visual Studio 2012 launch yesterday I think it\u2019s a good idea to announce two new type providers which are based on the DGMLTypeProvider from the F# 3.0 Sample Pack. Synchronous and asynchronous state machine The first one is only a small extension to the DGMLTypeProvider by Tao. which allows to generate state […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[12,448,8,34],"tags":[664,609,614],"_links":{"self":[{"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/posts\/1192"}],"collection":[{"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/comments?post=1192"}],"version-history":[{"count":11,"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/posts\/1192\/revisions"}],"predecessor-version":[{"id":1208,"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/posts\/1192\/revisions\/1208"}],"wp:attachment":[{"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/media?parent=1192"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/categories?post=1192"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/tags?post=1192"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}