FUNCTIONAL PEARL Type-safe cast Export

@article{citeulike:4491395, abstract = {Comparing two types for equality is an essential ingredient for an implementation of dynamic types. Once equality has been established, it is safe to cast a value from one type to another. In a language with run-time type analysis, implementing such a procedure is fairly straightforward. Unfortunately, this naive implementation destructs and rebuilds the argument while iterating over its type structure. However, by using higher-order polymorphism, a casting function can treat its argument parametrically. We demonstrate this solution in two frameworks for ad-hoc polymorphism: intensional type analysis and Haskell type classes.}, author = {Weirich, Stephanie}, citeulike-article-id = {4491395}, citeulike-linkout-0 = {http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=254715}, citeulike-linkout-1 = {http://dx.doi.org/10.1017/S0956796804005179}, doi = {10.1017/S0956796804005179}, journal = {Journal of Functional Programming}, keywords = {fundeps, haskell, typecast}, number = {06}, pages = {681--695}, posted-at = {2009-05-08 08:44:39}, priority = {2}, title = {FUNCTIONAL PEARL Type-safe cast}, url = {http://dx.doi.org/10.1017/S0956796804005179}, volume = {14}, year = {2004} }

TY - JOUR ID - citeulike:4491395 L3 - citeulike-article-id:4491395 N2 - Comparing two types for equality is an essential ingredient for an implementation of dynamic types. Once equality has been established, it is safe to cast a value from one type to another. In a language with run-time type analysis, implementing such a procedure is fairly straightforward. Unfortunately, this naive implementation destructs and rebuilds the argument while iterating over its type structure. However, by using higher-order polymorphism, a casting function can treat its argument parametrically. We demonstrate this solution in two frameworks for ad-hoc polymorphism: intensional type analysis and Haskell type classes. IS - 06 JF - Journal of Functional Programming EP - 695 TI - FUNCTIONAL PEARL Type-safe cast VL - 14 SP - 681 KW - fundeps KW - haskell KW - typecast AU - Weirich, Stephanie PY - 2004/// UR - http://dx.doi.org/10.1017/S0956796804005179 ER -