Module System.IO.Unsafe

Exported Functions

unsafePerformIO :: IO a -> a   

Performs and hides an I/O action in a computation (use with care!).

Further infos:

• externally defined

trace :: String -> a -> a   

Prints the first argument as a side effect and behaves as identity on the second argument.

Further infos:

• might behave indeterministically

spawnConstraint :: Bool -> a -> a   

Spawns a constraint and returns the second argument. This function can be considered as defined by spawnConstraint c x | c = x. However, the evaluation of the constraint and the right-hand side are performed concurrently, i.e., a suspension of the constraint does not imply a blocking of the right-hand side and the right-hand side might be evaluated before the constraint is successfully solved. Thus, a computation might return a result even if some of the spawned constraints are suspended (use the PAKCS option +suspend to show such suspended goals).

Further infos:

• externally defined

isVar :: Data a => a -> Bool   

Tests whether the first argument evaluates to a currently unbound variable (use with care!).

Further infos:

• might behave indeterministically

identicalVar :: Data a => a -> a -> Bool   

Tests whether both arguments evaluate to the identical currently unbound variable (use with care!). For instance,

identicalVar (id x) (fst (x,1))  where x free

evaluates to True, whereas

identicalVar x y  where x,y free

and

let x=1 in identicalVar x x

evaluate to False

Further infos:

• might behave indeterministically

isGround :: Data a => a -> Bool   

Tests whether the argument evaluates to a ground value (use with care!).

Further infos:

• might behave indeterministically

compareAnyTerm :: a -> a -> Ordering   

Comparison of any data terms, possibly containing variables. Data constructors are compared in the order of their definition in the datatype declarations and recursively in the arguments. Variables are compared in some internal order.

Further infos:

• externally defined

showAnyTerm :: a -> String   

Transforms the normal form of a term into a string representation in standard prefix notation. Thus, showAnyTerm evaluates its argument to normal form. This function is similar to the function ReadShowTerm.showTerm but it also transforms logic variables into a string representation that can be read back by Unsafe.read(s)AnyUnqualifiedTerm. Thus, the result depends on the evaluation and binding status of logic variables so that it should be used with care!

Further infos:

• might behave indeterministically

readsAnyUnqualifiedTerm :: [String] -> String -> [(a, String)]   

Transforms a string containing a term in standard prefix notation without module qualifiers into the corresponding data term. The string might contain logical variable encodings produced by showAnyTerm. In case of a successful parse, the result is a one element list containing a pair of the data term and the remaining unparsed string.

Further infos:

• might behave indeterministically

readAnyUnqualifiedTerm :: [String] -> String -> a   

Transforms a string containing a term in standard prefix notation without module qualifiers into the corresponding data term. The string might contain logical variable encodings produced by showAnyTerm.

Further infos:

• might behave indeterministically

showAnyExpression :: a -> String   

Transforms any expression (even not in normal form) into a string representation in standard prefix notation without module qualifiers. The result depends on the evaluation and binding status of logic variables so that it should be used with care!

Further infos:

• externally defined