Interesting! now I have more doubts about this: 1 Where is this cheap & fast implementation of the Java-like casting? Is it in GDK or it is implemented at low-level by the Groovy compiler? I only know the asType method in DefaultGroovyMethods. 2 Why the "asType" method use the expensive way new BigDecimal(d.toString()) instead the fast?
Thank you Jochen. :) On Mon, Jan 11, 2016 at 2:00 PM, Jochen Theodorou <blackd...@gmx.org> wrote: > We tryied to have two different kinds of casts. The normal one, that is > more in the style of Java, which tries the cheapest way. And the "as" > version, which calls into asType is customizable and usually does more > expensive operations. The fallback for asType is the normal cast. That's > why we see asType as an extended cast. But don't expect asType simply as > something that allows for more cases than the normal cast. I can have > different conversion logic. > > Now > > new BigDecimal(d) > > is much cheaper than > > new BigDecimal(d.toString()) > > That those two do not match is actually because of d.toString(), which > does simply give 1.9 here, instead of the exact double value. That this > toString() methods behaves in this way has not always been the case afaik. > > bye Jochen > > Am 11.01.2016 um 10:57 schrieb Alberto Vilches: > >> Yes, I know the "1.9" literal in Groovy results in a BigDecimal. That's >> why I'm trying to force the double using the "d", but maybe is still a >> bigdecimal. So, let's try again: >> >> Double d = 1.9 >> println((BigDecimal)d) >> >> prints "1.899999999999999911182158029987476766109466552734375" >> >> and >> >> Double d = 1.9 >> println d as BigDecimal >> >> prints "1.9" >> >> >> >> On Fri, Jan 8, 2016 at 1:34 PM, Naresha K. <naresh...@gmail.com >> <mailto:naresh...@gmail.com>> wrote: >> >> Value 1.9 will be of type BigDecimal. >> Why are you using D? >> >> >> On Fri, Jan 8, 2016 at 5:45 PM, Alberto Vilches <vilc...@gmail.com >> <mailto:vilc...@gmail.com>> wrote: >> >> Hi everybody! We have an issue in our application, and we >> realized these two lines have differents results. We wonder why >> because we think it should calls to the >> DefaultGroovyMethods.asType(Number self, Class<T> c). But it >> seems only the explicit call to "as" finally calls to the asType >> and the casting do a different thing (just a new >> BigDecimal(1.9D), but we wonder in which part of Groovy is >> happening) >> >> (BigDecimal)1.9D // >> "1.899999999999999911182158029987476766109466552734375" -> >> 1.9D as BigDecimal // "1.9" >> >> In fact, we tried to put these two lines in the Groovy console >> and see the AST in all the phases. But in all of them shows the >> same code: >> >> public java.lang.Object run() { >> ((1.9) as java.math.BigDecimal) >> return ((1.9) as java.math.BigDecimal) >> } >> >> Somebody please could give some light? Thank you very much and >> happy new year :) >> >> -- >> Un saludo. >> Alberto Vilches >> >> >> >> >> >> -- >> Un saludo. >> Alberto Vilches >> > -- Un saludo. Alberto Vilches
