GHC.JS.Make

• Domain and Purpose

  GHC.JS.Make defines helper functions to ease the creation of JavaScript ASTs as defined in Syntax. Its purpose is twofold: make the EDSL more ergonomic to program in, and make errors in the EDSL look obvious because the EDSL is untyped. It is primarily concerned with injecting terms into the domain of the EDSL to construct JS programs in Haskell.

• Strategy

  The strategy for this module comes straight from gentzen; where we have two types of helper functions. Functions which inject terms into the EDSL, and combinator functions which operate on terms in the EDSL to construct new terms in the EDSL. Crucially, missing from this module are corresponding elimination or destructing functions which would project information from the EDSL back to Haskell. See Utils for such functions.

  • Introduction functions

    We define various primitive helpers which introduce terms in the EDSL, for example jVar, jLam, and var and jString. Notice that the type of each of these functions have the domain isSat a => a -> ...; indicating that they each take something that can be injected into the EDSL domain, and the range JExpr or JStat; indicating the corresponding value in the EDSL domain. Similarly this module exports two typeclasses ToExpr and ToSat, ToExpr injects values as a JS expression into the EDSL. ToSat ensures that terms introduced into the EDSL carry identifier information so terms in the EDSL must have meaning.

  • Combinator functions

    The rest of the module defines combinators which create terms in the EDSL from terms in the EDSL. Notable examples are |= and ||=, |= is sugar for AssignStat, it is a binding form that declares foo = bar assuming foo has been already declared. ||= is more sugar on top of |=, it is also a binding form that declares the LHS of |= before calling |= to bind a value, bar, to a variable foo. Other common examples are the if_ and math_ helpers such as math_cos.

• Consumers

  The entire JS backend consumes this module, e.g., the modules in GHC.StgToJS.*.

• Notation

  In this module we use ==> in docstrings to show the translation from the JS EDSL domain to JS code. For example, foo ||= bar ==> var foo; foo = bar; should be read as foo ||= bar is in the EDSL domain and results in the JS code var foo; foo = bar; when compiled.

Injection Type classes

The ToJExpr class handles injection of of things into the EDSL as a JS expression

class ToJExpr a where

Things that can be marshalled into javascript values. Instantiate for any necessary data structures.

Minimal complete definition

toJExpr

Methods

toJExpr :: a -> JExpr

toJExprFromList :: [a] -> JExpr

Instances

ToJExpr FastString

Defined in GHC.JS.Make

Methods

toJExpr :: FastString -> JExpr

toJExprFromList :: [FastString] -> JExpr

ToJExpr Ident

Defined in GHC.JS.Make

Methods

toJExpr :: Ident -> JExpr

toJExprFromList :: [Ident] -> JExpr

ToJExpr JExpr

Defined in GHC.JS.Make

Methods

toJExpr :: JExpr -> JExpr

toJExprFromList :: [JExpr] -> JExpr

ToJExpr JVal

Defined in GHC.JS.Make

Methods

toJExpr :: JVal -> JExpr

toJExprFromList :: [JVal] -> JExpr

ToJExpr CIStatic

static refs: array = references, null = nothing to report note: only works after all top-level objects have been created

Defined in GHC.StgToJS.Types

Methods

toJExpr :: CIStatic -> JExpr

toJExprFromList :: [CIStatic] -> JExpr

ToJExpr ClosureType

Defined in GHC.StgToJS.Types

Methods

toJExpr :: ClosureType -> JExpr

toJExprFromList :: [ClosureType] -> JExpr

ToJExpr StaticLit

Defined in GHC.StgToJS.Types

Methods

toJExpr :: StaticLit -> JExpr

toJExprFromList :: [StaticLit] -> JExpr

ToJExpr VarType

Defined in GHC.StgToJS.Types

Methods

toJExpr :: VarType -> JExpr

toJExprFromList :: [VarType] -> JExpr

ToJExpr Integer

Defined in GHC.JS.Make

Methods

toJExpr :: Integer -> JExpr

toJExprFromList :: [Integer] -> JExpr

ToJExpr ()

Defined in GHC.JS.Make

Methods

toJExpr :: () -> JExpr

toJExprFromList :: [()] -> JExpr

ToJExpr Bool

Defined in GHC.JS.Make

Methods

toJExpr :: Bool -> JExpr

toJExprFromList :: [Bool] -> JExpr

ToJExpr Char

Defined in GHC.JS.Make

Methods

toJExpr :: Char -> JExpr

toJExprFromList :: [Char] -> JExpr

ToJExpr Double

Defined in GHC.JS.Make

Methods

toJExpr :: Double -> JExpr

toJExprFromList :: [Double] -> JExpr

ToJExpr Int

Defined in GHC.JS.Make

Methods

toJExpr :: Int -> JExpr

toJExprFromList :: [Int] -> JExpr

ToJExpr a => ToJExpr [a]

Defined in GHC.JS.Make

Methods

toJExpr :: [a] -> JExpr

toJExprFromList :: [[a]] -> JExpr

ToJExpr a => ToJExpr (Map String a)

Defined in GHC.JS.Make

Methods

toJExpr :: Map String a -> JExpr

toJExprFromList :: [Map String a] -> JExpr

ToJExpr a => ToJExpr (UniqMap FastString a)

Defined in GHC.JS.Make

Methods

toJExpr :: UniqMap FastString a -> JExpr

toJExprFromList :: [UniqMap FastString a] -> JExpr

(ToJExpr a, ToJExpr b) => ToJExpr (a, b)

Defined in GHC.JS.Make

Methods

toJExpr :: (a, b) -> JExpr

toJExprFromList :: [(a, b)] -> JExpr

(ToJExpr a, ToJExpr b, ToJExpr c) => ToJExpr (a, b, c)

Defined in GHC.JS.Make

Methods

toJExpr :: (a, b, c) -> JExpr

toJExprFromList :: [(a, b, c)] -> JExpr

(ToJExpr a, ToJExpr b, ToJExpr c, ToJExpr d) => ToJExpr (a, b, c, d)

Defined in GHC.JS.Make

Methods

toJExpr :: (a, b, c, d) -> JExpr

toJExprFromList :: [(a, b, c, d)] -> JExpr

(ToJExpr a, ToJExpr b, ToJExpr c, ToJExpr d, ToJExpr e) => ToJExpr (a, b, c, d, e)

Defined in GHC.JS.Make

Methods

toJExpr :: (a, b, c, d, e) -> JExpr

toJExprFromList :: [(a, b, c, d, e)] -> JExpr

(ToJExpr a, ToJExpr b, ToJExpr c, ToJExpr d, ToJExpr e, ToJExpr f) => ToJExpr (a, b, c, d, e, f)

Defined in GHC.JS.Make

Methods

toJExpr :: (a, b, c, d, e, f) -> JExpr

toJExprFromList :: [(a, b, c, d, e, f)] -> JExpr

class ToStat a where

The ToStat class handles injection of of things into the EDSL as a JS statement. This ends up being polymorphic sugar for JS blocks, see helper function expr2stat. Instantiate for any necessary data structures.

Methods

toStat :: a -> JStat

Instances

ToStat JExpr

Defined in GHC.JS.Make

Methods

toStat :: JExpr -> JStat

ToStat JStat

Defined in GHC.JS.Make

Methods

toStat :: JStat -> JStat

ToStat [JExpr]

Defined in GHC.JS.Make

Methods

toStat :: [JExpr] -> JStat

ToStat [JStat]

Defined in GHC.JS.Make

Methods

toStat :: [JStat] -> JStat

Introduction functions

var :: FastString -> JExpr

construct a JS variable reference

jString :: FastString -> JExpr

Convert a ShortText to a Javascript String

jLam :: ToSat a => a -> JExpr

Create a new anonymous function. The result is a JExpr expression. Usage:

jLam $ \x -> jVar x + one_
jLam $ \f -> (jLam $ \x -> (f `app` (x `app` x))) `app` (jLam $ \x -> (f `app` (x `app` x)))

jFun :: ToSat a => Ident -> a -> JStat

Create a new function. The result is a JStat. Usage:

jFun fun_name $ \x -> ...

jFunction :: Ident -> [Ident] -> JStat -> JStat

jVar :: ToSat a => a -> JStat

Introduce a new variable into scope for the duration of the enclosed expression. The result is a block statement. Usage:

jVar $ x y -> mconcat [x ||= one_, y ||= two_, x + y]

jFor :: (JExpr -> JStat) -> (JExpr -> JExpr) -> (JExpr -> JStat) -> (JExpr -> JStat) -> JStat

Create a for statement given a function for initialization, a predicate to step to, a step and a body Usage:

 jFor (|= zero_) (.<. Int 65536) preIncrS
        (j -> ...something with the counter j...)

jForNoDecl :: Ident -> JExpr -> JExpr -> JStat -> JStat -> JStat

jForIn :: ToSat a => JExpr -> (JExpr -> a) -> JStat

Create a 'for in' statement. Usage:

jForIn {expression} $ x -> {block involving x}

jForEachIn :: ToSat a => JExpr -> (JExpr -> a) -> JStat

As with "jForIn" but creating a "for each in" statement.

jTryCatchFinally :: ToSat a => JStat -> a -> JStat -> JStat

As with "jForIn" but creating a "for each in" statement.

Combinators

Combinators operate on terms in the JS EDSL domain to create new terms in the EDSL domain.

(||=) :: Ident -> JExpr -> JStat infixl 2

Declare a variable and then Assign the variable to an expression

foo |= expr ==> var foo; foo = expr;

(|=) :: JExpr -> JExpr -> JStat infixl 2

Assign a variable to an expression

foo |= expr ==> var foo = expr;

(.==.) :: JExpr -> JExpr -> JExpr infixl 6

JS infix Equality operators

(.===.) :: JExpr -> JExpr -> JExpr infixl 6

JS infix Equality operators

(.!=.) :: JExpr -> JExpr -> JExpr infixl 6

JS infix Equality operators

(.!==.) :: JExpr -> JExpr -> JExpr infixl 6

JS infix Equality operators

(.!) :: JExpr -> JExpr -> JExpr infixl 8

return the expression at idx of obj

obj .! idx ==> obj[idx]

(.>.) :: JExpr -> JExpr -> JExpr infixl 7

JS infix Ord operators

(.>=.) :: JExpr -> JExpr -> JExpr infixl 7

JS infix Ord operators

(.<.) :: JExpr -> JExpr -> JExpr infixl 7

JS infix Ord operators

(.<=.) :: JExpr -> JExpr -> JExpr infixl 7

JS infix Ord operators

(.<<.) :: JExpr -> JExpr -> JExpr infixl 9

JS infix bit shift operators

(.>>.) :: JExpr -> JExpr -> JExpr infixl 9

JS infix bit shift operators

(.>>>.) :: JExpr -> JExpr -> JExpr infixl 9

JS infix bit shift operators

(.|.) :: JExpr -> JExpr -> JExpr

JS infix bit operators

(.||.) :: JExpr -> JExpr -> JExpr infixl 8

JS infix bit operators

(.&&.) :: JExpr -> JExpr -> JExpr infixl 8

JS infix bit operators

if_ :: JExpr -> JExpr -> JExpr -> JExpr

JS if-expression

if_ e1 e2 e3 ==> e1 ? e2 : e3

if10 :: JExpr -> JExpr

if-expression that returns 1 if condition = true, 0 otherwise

if10 e ==> e ? 1 : 0

if01 :: JExpr -> JExpr

if-expression that returns 0 if condition = true, 1 otherwise

if01 e ==> e ? 0 : 1

ifS :: JExpr -> JStat -> JStat -> JStat

If-expression which returns statements, see related ifBlockS

if e s1 s2 ==> if(e) { s1 } else { s2 }

ifBlockS :: JExpr -> [JStat] -> [JStat] -> JStat

If-expression which returns blocks

ifBlockS e s1 s2 ==> if(e) { s1 } else { s2 }

jwhenS :: JExpr -> JStat -> JStat

A when-statement as syntactic sugar via ifS

jwhenS cond block ==> if(cond) { block } else {  }

app :: FastString -> [JExpr] -> JExpr

an expression application, see related appS

app f xs ==> f(xs)

appS :: FastString -> [JExpr] -> JStat

A statement application, see the expression form app

returnS :: JExpr -> JStat

Return a JExpr

loop :: JExpr -> (JExpr -> JExpr) -> (JExpr -> JStat) -> JStat

"for" loop with increment at end of body

loopBlockS :: JExpr -> (JExpr -> JExpr) -> (JExpr -> [JStat]) -> JStat

"for" loop with increment at end of body

preIncrS :: JExpr -> JStat

Prefix-increment a JExpr

postIncrS :: JExpr -> JStat

Postfix-increment a JExpr

preDecrS :: JExpr -> JStat

Prefix-decrement a JExpr

postDecrS :: JExpr -> JStat

Postfix-decrement a JExpr

off8 :: JExpr -> JExpr -> JExpr

Byte indexing of o with a 8-bit offset

off16 :: JExpr -> JExpr -> JExpr

Byte indexing of o with a 16-bit offset

off32 :: JExpr -> JExpr -> JExpr

Byte indexing of o with a 32-bit offset

off64 :: JExpr -> JExpr -> JExpr

Byte indexing of o with a 64-bit offset

mask8 :: JExpr -> JExpr

a bit mask to retrieve the lower 8-bits

mask16 :: JExpr -> JExpr

a bit mask to retrieve the lower 16-bits

signExtend8 :: JExpr -> JExpr

Sign-extend/narrow a 8-bit value

signExtend16 :: JExpr -> JExpr

Sign-extend/narrow a 16-bit value

typeof :: JExpr -> JExpr

Given a JExpr, return the its type.

returnStack :: JStat

assignAllEqual :: HasDebugCallStack => [JExpr] -> [JExpr] -> JStat

assignAll :: [JExpr] -> [JExpr] -> JStat

assignAllReverseOrder :: [JExpr] -> [JExpr] -> JStat

declAssignAll :: [Ident] -> [JExpr] -> JStat

nullStat :: JStat

The empty JS statement

(.^) :: JExpr -> FastString -> JExpr infixl 8

Select a property prop, from and object obj

obj .^ prop ==> obj.prop

trace :: ToJExpr a => a -> JStat

Hash combinators

jhEmpty :: Map k JExpr

The empty JS HashMap

jhSingle :: (Ord k, ToJExpr a) => k -> a -> Map k JExpr

A singleton JS HashMap

jhAdd :: (Ord k, ToJExpr a) => k -> a -> Map k JExpr -> Map k JExpr

insert a key-value pair into a JS HashMap

jhFromList :: [(FastString, JExpr)] -> JVal

Construct a JS HashMap from a list of key-value pairs

Literals

Literals in the JS EDSL are constants in the Haskell domain. These are useful helper values and never change

null_ :: JExpr

The JS literal null

undefined_ :: JExpr

The JS literal undefined

false_ :: JExpr

The JS literal false

true_ :: JExpr

The JS literal true

zero_ :: JExpr

The JS literal 0

one_ :: JExpr

The JS literal 1

two_ :: JExpr

The JS literal 2

three_ :: JExpr

The JS literal 3

Math functions

Math functions in the EDSL are literals, with the exception of math_ which is the sole math introduction function.

math_log :: [JExpr] -> JExpr

math_sin :: [JExpr] -> JExpr

math_cos :: [JExpr] -> JExpr

math_tan :: [JExpr] -> JExpr

math_exp :: [JExpr] -> JExpr

math_acos :: [JExpr] -> JExpr

math_asin :: [JExpr] -> JExpr

math_atan :: [JExpr] -> JExpr

math_abs :: [JExpr] -> JExpr

math_pow :: [JExpr] -> JExpr

math_sqrt :: [JExpr] -> JExpr

math_asinh :: [JExpr] -> JExpr

math_acosh :: [JExpr] -> JExpr

math_atanh :: [JExpr] -> JExpr

math_cosh :: [JExpr] -> JExpr

math_sinh :: [JExpr] -> JExpr

math_tanh :: [JExpr] -> JExpr

math_expm1 :: [JExpr] -> JExpr

math_log1p :: [JExpr] -> JExpr

math_fround :: [JExpr] -> JExpr

Statement helpers

decl :: Ident -> JStat

construct a js declaration with the given identifier

Orphan instances

Num JExpr

Methods

(+) :: JExpr -> JExpr -> JExpr

(-) :: JExpr -> JExpr -> JExpr

(*) :: JExpr -> JExpr -> JExpr

negate :: JExpr -> JExpr

abs :: JExpr -> JExpr

signum :: JExpr -> JExpr

fromInteger :: Integer -> JExpr

Fractional JExpr

Methods

(/) :: JExpr -> JExpr -> JExpr

recip :: JExpr -> JExpr

fromRational :: Rational -> JExpr