problem about typechecking-Collection of common programming errors

• 
  Nathan Kleyn
  debugging haskell types typechecking
  compress xs@(_:_:_) = (ifte ((==) head head.tail) ((compress.).(:) head tail.tail) ((:) head compress.tail) ) xsResults in a type error, but I can’t see why. It should be equivalent tocompress xs@(_:_:_) = (ifte (((==) head head.tail) xs) (((compress.).(:) he
• 
  Eric
  reflection haskell typechecking
  This is a minimal example taken from the Reflection-0.5.{-# LANGUAGE Rank2Types, MultiParamTypeClasses, FunctionalDependencies, FlexibleInstances #-} {-# OPTIONS_GHC -fno-cse -fno-full-laziness -fno-float-in #-}import Control.Applicative import Data.Proxynewtype Zero = Zero Zero deriving (Sho
• 
  Masterofpsi
  c++ boost polymorphism assignment-operator typechecking
  all. I’m pretty new to C++, and I’m writing a small library (mostly for my own projects) in C++. In the process of designing a type hierarchy, I’ve run into the problem of defining the assignment operator.I’ve taken the basic approach that was eventually reached in this article, which is that for every class MyClass in a hierarchy derived from a class Base you define two assignment operators like so:class MyClass: public Base { public:MyClass& operator =(MyClass const& rhs);virtual MyClass& operator =(Base const& rhs); };// automatically
• 
  Mitch Wheat
  javascript typechecking
  I’m currently in the creation of a javascript function library. Mainly for my own use, but you can never be sure if someone else ends up using it in their projects, I’m atleast creating it as if that could happen. Most methods only work if the variables that are p
• 
  Soverman
• 
  Ned
  javascript types google-closure-compiler typechecking
  I’m messing around with the type checking in google’s closure compiler. The type system seems useful, if perhaps not the most sophisticated out there. I’m happy with most of the limitations, but this one just seems a bit weird.I’m seeing problems giving type annotations for functions passed as arguments. In particular, if the type of the passed function is itself not fixed. So for example, I’d like to write code similar to this:/*** @param {Array} xs* @param {function(*) : boolean} f* @return {Array}*/ var filter = function (xs, f) {var i, resu
• 
  Peter Mortensen
• 
  Viclib
• 
  pek
  php typechecking
  Is there any way to force PHP to blow up (error, whatever) if I misspell a variable name? What about if I’m using an instance of a class an
• 
  deeb
  ruby class typechecking genetics
  On runtime, my code often come into an undefined method error for the method mate. As far as I can figure, a Person somehow slips through the cracks sometime along the code’s exucution, and manages not to have an allele assigned to it.Code (disclaimer, not the best formatted):class Alleleattr_accessor :c1, :c2def initialize(c1, c2)@c1 = c1@c2 = c2end#formats it to be readabledef to_sc1.to_s + c2.to_send#given Allele adef combine(a)pick = rand(4)case pickwhen 0Allele.new(c1,a.c1)when 1Allele.new(c1,a.c2)when 2Allele.new(c2,a.c1)when 3Allele.new(c2,a.c2)endend endclass
• 
  Nathan Kleyn
• 
  fish2000
  python validation numpy introspection typechecking
  I want to test an unknown value against the constraints that a given NumPy dtype implies — e.g., if I have an integer value, is it small enough to fit in a uint8?As best I can ascertain, NumPy’s dtype architecture doesn’t offer a way to do something like this:### FICTIONAL NUMPY CODE: I made this up ### try:numpy.uint8.validate(rupees) except nump
• 
  Davorak
  haskell dynamic-loading typechecking ghc-api
  I have the following code that uses the GHC API to load modules and get the type of an expression:typeObjects :: [String] -> [String] -> IO [Type] typeObjects modules objects = dodefaultErrorHandler defaultDynFlags $ dorunGhc (Just libdir) $

Originally posted 2013-11-09 20:19:30.