| Portability | portable |
|---|---|
| Stability | experimental |
| Maintainer | golubovsky@gmail.com |
Language.JSMW.Arith
Description
Encoding of Javascript arithmetic and mathematic operations.
- lt :: Expression a -> Expression a -> Expression Bool
- le :: Expression a -> Expression a -> Expression Bool
- gt :: Expression a -> Expression a -> Expression Bool
- ge :: Expression a -> Expression a -> Expression Bool
- eq :: Expression a -> Expression a -> Expression Bool
- ne :: Expression a -> Expression a -> Expression Bool
- (===) :: Expression a -> Expression a -> Expression Bool
- (=/=) :: Expression a -> Expression a -> Expression Bool
- land :: Expression Bool -> Expression Bool -> Expression Bool
- lor :: Expression Bool -> Expression Bool -> Expression Bool
- isNAN :: Expression Double -> JSMW e (Expression Bool)
- toString :: Expression a -> JSMW e (Expression String)
- parseInt :: Expression String -> Expression Double -> JSMW e (Expression Double)
- parseFloat :: Expression String -> JSMW e (Expression Double)
Arithmetic operators
Instance of the Num class can be defined for Javascript expressions
provided that their type annotation also belongs to the Num class. Therefore
it is possible to overload the +, -, etc. operators so that using them
in JSMW code would result in correct Javascript code:
number5 - (number1 -number4)
results in
(5.0 - (1.0 - 4.0)).
Also, addition is defined for String expressions, so this is possible:
alert(g +string" Greater than 3")
Unlike the methods of the Num class, comparison operators (members of the Ord
class) cannot be overloaded in suitable manner. For Javascript expressions,
the following infix operators are provided, with the same fixity as the corresponding
Haskell operators.
lt :: Expression a -> Expression a -> Expression BoolSource
le :: Expression a -> Expression a -> Expression BoolSource
gt :: Expression a -> Expression a -> Expression BoolSource
ge :: Expression a -> Expression a -> Expression BoolSource
eq :: Expression a -> Expression a -> Expression BoolSource
ne :: Expression a -> Expression a -> Expression BoolSource
(===) :: Expression a -> Expression a -> Expression BoolSource
(=/=) :: Expression a -> Expression a -> Expression BoolSource
Logical operators
Similarly, logical operators for Javascript expressions are provided.
land :: Expression Bool -> Expression Bool -> Expression BoolSource
lor :: Expression Bool -> Expression Bool -> Expression BoolSource
Tests for being a number
isNAN :: Expression Double -> JSMW e (Expression Bool)Source
Test if a given value is a number.
Primitive conversions
toString :: Expression a -> JSMW e (Expression String)Source
Obtain a string representation of an arbitrary Javascript expression.
parseInt :: Expression String -> Expression Double -> JSMW e (Expression Double)Source
Parse an integer.
parseFloat :: Expression String -> JSMW e (Expression Double)Source
Parse a floating point number.