Comment made by: slipset
So, I guess some division by zero is somewhat undefined.
If one removes
`
if(yops.isZero((Number)y))
throw new ArithmeticException("Divide by zero");
`
then
(/ (identity 5.0) (identity 0.0))
returns infinity as the unboxed versions.
Although doing so, also causes a change to
(/ 5 0)
which then becomes 1/0, whereas it previously threw Divide by zero.
From Numbers.java we see that unboxed math does not protect against division by zero:
`
static public double divide(double x, double y){
return x / y;
}
`
whereas boxed versions do:
`
static public Number divide(Object x, Object y){
if (isNaN(x)){
return (Number)x;
} else if(isNaN(y)){
return (Number)y;
}
Ops yops = ops(y);
if(yops.isZero((Number)y))
throw new ArithmeticException("Divide by zero");
return ops(x).combine(yops).divide((Number)x, (Number)y);
}
`
This inconsistency is also reproducible with clojure 1.8:
`
Clojure 1.8.0
Java HotSpot(TM) 64-Bit Server VM 1.8.0_144-b01
Docs: (doc function-name-here)
(find-doc "part-of-name-here")
Source: (source function-name-here)
Javadoc: (javadoc java-object-or-class-here)
Exit: Control+D or (exit) or (quit)
Results: Stored in vars 1, 2, 3, an exception in e
user=> (/ 5.0 0.0)
Infinity
user=> (/ (identity 5.0) (identity 0.0))
ArithmeticException Divide by zero clojure.lang.Numbers.divide (Numbers.java:158)
user=>
`
