haskell - Comparing design by contract to type systems -

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i read paper compared design-by-contract test-driven-development. there seems lot of overlap, redundancy, , little bit of synergy between dbc , tdd. example, there systems automatically generating tests based on contracts.

in way dbc overlap modern type system (such in haskell, or 1 of dependently typed languages) , there points using both better either?

the paper "typed contracts functional programming" ralf hinze, johan jeuring, , andres löh had handy table illustrates whereabouts contracts sit in design spectrum of "checking":

                   |   static checking    |   dynamic checking ------------------------------------------------------------------- simple properties  | static type checking | dynamic type checking complex properties | theorem proving      | contract checking

see here:

http://people.cs.uu.nl/andres/contracts.html


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