Copyright | (C) 2013 Amgen Inc. |
---|---|
Safe Haskell | None |
Language | Haskell2010 |
Definition of SEXPTYPE
, which classifies the possible forms of an
R expression (a SEXP
). It is normally not necessary to import this module
directly, since it is reexported by Foreign.R.
This is done in a separate module because we want to use hsc2hs rather than
c2hs for discharging the boilerplate around SEXPTYPE
. This is because
SEXPTYPE
is nearly but not quite a true enumeration and c2hs has trouble
dealing with that.
This module also defines a singleton version of SEXPTYPE
, called
SSEXPTYPE
. This is actually a family of types, one for each possible
SEXPTYPE
. Singleton types are a way of emulating dependent types in
a language that does not have true dependent type. They are useful in
functions whose result type depends on the value of one of its arguments. See
e.g. allocVector
.
Synopsis
- data SEXPTYPE
- data SSEXPTYPE :: SEXPTYPE -> Type where
- SNil :: SSEXPTYPE 'Nil
- SSymbol :: SSEXPTYPE 'Symbol
- SList :: SSEXPTYPE 'List
- SClosure :: SSEXPTYPE 'Closure
- SEnv :: SSEXPTYPE 'Env
- SPromise :: SSEXPTYPE 'Promise
- SLang :: SSEXPTYPE 'Lang
- SSpecial :: SSEXPTYPE 'Special
- SBuiltin :: SSEXPTYPE 'Builtin
- SChar :: SSEXPTYPE 'Char
- SLogical :: SSEXPTYPE 'Logical
- SInt :: SSEXPTYPE 'Int
- SReal :: SSEXPTYPE 'Real
- SComplex :: SSEXPTYPE 'Complex
- SString :: SSEXPTYPE 'String
- SDotDotDot :: SSEXPTYPE 'DotDotDot
- SAny :: SSEXPTYPE 'Any
- SVector :: SSEXPTYPE 'Vector
- SExpr :: SSEXPTYPE 'Expr
- SBytecode :: SSEXPTYPE 'Bytecode
- SExtPtr :: SSEXPTYPE 'ExtPtr
- SWeakRef :: SSEXPTYPE 'WeakRef
- SRaw :: SSEXPTYPE 'Raw
- SS4 :: SSEXPTYPE 'S4
- SNew :: SSEXPTYPE 'New
- SFree :: SSEXPTYPE 'Free
- SFun :: SSEXPTYPE 'Fun
- type family Sing :: k -> Type
- data Logical
- type PairList = List
- type IsVector (a :: SEXPTYPE) = (SingI a, a :∈ ('Char ': ('Logical ': ('Int ': ('Real ': ('Complex ': ('String ': ('Vector ': ('Expr ': ('WeakRef ': ('Raw ': '[])))))))))))
- type IsGenericVector (a :: SEXPTYPE) = (SingI a, a :∈ [Vector, Expr, WeakRef])
- type IsList (a :: SEXPTYPE) = (SingI a, a :∈ ('Char ': ('Logical ': ('Int ': ('Real ': ('Complex ': ('String ': ('Vector ': ('Expr ': ('WeakRef ': ('Raw ': (List ': '[]))))))))))))
- type IsPairList (a :: SEXPTYPE) = (SingI a, a :∈ [List, Nil])
- type IsExpression (a :: SEXPTYPE) = (SingI a, a :∈ [Lang, Expr, Symbol])
Documentation
R "type". Note that what R calls a "type" is not what is usually meant
by the term: there is really only a single type, called SEXP
, and an
R "type" in fact refers to the class or form of the expression.
To better illustrate the distinction, note that any sane type system normally
has the subject reduction property: that the type of an expression is
invariant under reduction. For example, (x -> x) 1
has type Int
, and so
does the value of this expression, 2
, have type Int
. Yet the form of
the expression is an application of a function to a literal, while the form
of its reduct is an integer literal.
We introduce convenient Haskell-like names for forms because this datatype is
used to index SEXP
and other types through the DataKinds
extension.
Nil | |
Symbol | |
List | |
Closure | |
Env | |
Promise | |
Lang | |
Special | |
Builtin | |
Char | |
Logical | |
Int | |
Real | |
Complex | |
String | |
DotDotDot | |
Any | |
Vector | |
Expr | |
Bytecode | |
ExtPtr | |
WeakRef | |
Raw | |
S4 | |
New | |
Free | |
Fun |
Instances
data SSEXPTYPE :: SEXPTYPE -> Type where Source #
SNil :: SSEXPTYPE 'Nil | |
SSymbol :: SSEXPTYPE 'Symbol | |
SList :: SSEXPTYPE 'List | |
SClosure :: SSEXPTYPE 'Closure | |
SEnv :: SSEXPTYPE 'Env | |
SPromise :: SSEXPTYPE 'Promise | |
SLang :: SSEXPTYPE 'Lang | |
SSpecial :: SSEXPTYPE 'Special | |
SBuiltin :: SSEXPTYPE 'Builtin | |
SChar :: SSEXPTYPE 'Char | |
SLogical :: SSEXPTYPE 'Logical | |
SInt :: SSEXPTYPE 'Int | |
SReal :: SSEXPTYPE 'Real | |
SComplex :: SSEXPTYPE 'Complex | |
SString :: SSEXPTYPE 'String | |
SDotDotDot :: SSEXPTYPE 'DotDotDot | |
SAny :: SSEXPTYPE 'Any | |
SVector :: SSEXPTYPE 'Vector | |
SExpr :: SSEXPTYPE 'Expr | |
SBytecode :: SSEXPTYPE 'Bytecode | |
SExtPtr :: SSEXPTYPE 'ExtPtr | |
SWeakRef :: SSEXPTYPE 'WeakRef | |
SRaw :: SSEXPTYPE 'Raw | |
SS4 :: SSEXPTYPE 'S4 | |
SNew :: SSEXPTYPE 'New | |
SFree :: SSEXPTYPE 'Free | |
SFun :: SSEXPTYPE 'Fun |
type family Sing :: k -> Type #
The singleton kind-indexed type family.
Instances
R uses three-valued logic.
Instances
Eq Logical Source # | |
Ord Logical Source # | |
Show Logical Source # | |
Storable Logical Source # | |
Literal Logical 'Logical Source # | |
Literal [Logical] 'Logical Source # | |
Used where the R documentation speaks of "pairlists", which are really just regular lists.
type IsVector (a :: SEXPTYPE) = (SingI a, a :∈ ('Char ': ('Logical ': ('Int ': ('Real ': ('Complex ': ('String ': ('Vector ': ('Expr ': ('WeakRef ': ('Raw ': '[]))))))))))) Source #
Constraint synonym grouping all vector forms into one class. IsVector a
holds iff R's is.vector()
returns TRUE
.
type IsGenericVector (a :: SEXPTYPE) = (SingI a, a :∈ [Vector, Expr, WeakRef]) Source #
Non-atomic vector forms. See src/main/memory.c:SET_VECTOR_ELT
in the
R source distribution.
type IsList (a :: SEXPTYPE) = (SingI a, a :∈ ('Char ': ('Logical ': ('Int ': ('Real ': ('Complex ': ('String ': ('Vector ': ('Expr ': ('WeakRef ': ('Raw ': (List ': '[])))))))))))) Source #
IsList a
holds iff R's is.list()
returns TRUE
.