Was (wer) ist type inference - definition
AUTOMATIC DETECTION OF THE DATA TYPE OF AN EXPRESSION IN A PROGRAMMING LANGUAGE
Inferred typing; Type recontruction; Type reconstruction; Typability; Typability problem; Type deduction
type inference
<programming> An algorithm for ascribing types to
expressions in some language, based on the types of the
constants of the language and a set of type inference rules
such as
f :: A -> B, x :: A
--------------------- (App)
f x :: B
This rule, called "App" for application, says that if
expression f has type A -> B and expression x has type A then
we can deduce that expression (f x) has type B. The
expressions above the line are the premises and below, the
conclusion. An alternative notation often used is:
G |- x : A
where "|-" is the turnstile symbol (LaTeX vdash) and G is a
type assignment for the free variables of expression x. The
above can be read "under assumptions G, expression x has type
A". (As in Haskell, we use a double "::" for type
declarations and a single ":" for the infix list constructor,
cons).
Given an expression
plus (head l) 1
we can label each subexpression with a type, using type
variables X, Y, etc. for unknown types:
(plus :: Int -> Int -> Int)
(((head :: [a ] -> a) (l :: Y)) :: X)
(1 :: Int)
We then use unification on type variables to match the
partial application of plus to its first argument against
the App rule, yielding a type (Int -> Int) and a substitution
X = Int. Re-using App for the application to the second
argument gives an overall type Int and no further
substitutions. Similarly, matching App against the
application (head l) we get Y = [X ]. We already know X = Int
so therefore Y = [Int ].
This process is used both to infer types for expressions and
to check that any types given by the user are consistent.
See also generic type variable, principal type.
(1995-02-03)
Type inference
Type inference refers to the automatic detection of the type of an expression in a formal language. These include programming languages and mathematical type systems, but also natural languages in some branches of computer science and linguistics.
Statistical inference
PROCESS OF DEDUCING PROPERTIES OF AN UNDERLYING PROBABILITY DISTRIBUTION BY ANALYSIS OF DATA
InterpretingStatisticalData; Interpreting statistical data; Inferential statistics; Statistical analysis; Non-parametric inference; Inferential Statistics; Inductive strength; Inductive statistics; Statistical induction; Predictive inference; Statistics/Inference; Interpreting Statistical Data; Statistical Inference; Sampling statistics; Prediction theory; Inference (machine learning)
Statistical inference is the process of using data analysis to infer properties of an underlying distribution of probability.Upton, G.
Wikipedia
Type inference
Type inference refers to the automatic detection of the type of an expression in a formal language. These include programming languages and mathematical type systems, but also natural languages in some branches of computer science and linguistics.
