[jira] [Updated] (THRIFT-4476) Typecasting problem on list items

["James E. King, III (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/THRIFT-4476?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

James E. King, III updated THRIFT-4476:
---------------------------------------
    Component/s: Python - Compiler
                 JavaScript - Compiler
                 Erlang - Compiler
                 C++ - Compiler

> Typecasting problem on list items
> ---------------------------------
>
>                 Key: THRIFT-4476
>                 URL: https://issues.apache.org/jira/browse/THRIFT-4476
>             Project: Thrift
>          Issue Type: Bug
>          Components: C++ - Compiler, Erlang - Compiler, Java - Compiler, JavaScript - Compiler, Python - Compiler
>    Affects Versions: 0.11.0
>            Reporter: Ozan Can Altiok
>            Assignee: James E. King, III
>            Priority: Major
>             Fix For: 0.12.0
>
>
> I was trying to add the following into a thrift interface file.
> {{const list<double> timeCoefficients = [24, 60, 60, 1000, 1000, 1000]}}
> With the definition given above the {{.thrift}} file compiled properly. However, I noticed that in Python, the items in {{timeCoefficients}} are considered to be integer although the list has been defined to include items of {{double}} type. Then I modified the definition as given below to make sure all the items are of type {{double}}. 
> {{const list<double> timeCoefficients = [24.0, 60.0, 60.0, 1000.0, 1000.0, 1000.0]}}
> After the change, I ran into the following error during compilation.
> {{[ERROR] .../TimeCoefficients.java:[402,48] error: no suitable method found for add(int)}}
>  {{[ERROR] method Collection.add(Double) is not applicable}}
>  {{[ERROR] (argument mismatch; int cannot be converted to Double)}}
>  {{[ERROR] method List.add(Double) is not applicable}}
>  {{[ERROR] (argument mismatch; int cannot be converted to Double)}}
> Next, I changed the line as follows and the compilation became successful.
> {{const list<double> timeCoefficients = [24.1, 60.1, 60.1, 1000.1, 1000.1, 1000.1]}}
> When I reviewed the generated Java source files, I discovered that
> {{const list<double> timeCoefficients = [24, 60, 60, 1000, 1000, 1000]}}
> compiles to
> {{public static final java.util.List<java.lang.Double> timeCoefficients = new java.util.ArrayList<java.lang.Double>();}}
> {{static {}}
> {{  timeCoefficients.add((double)24);}}
>  {{  timeCoefficients.add((double)60);}}
>  {{  timeCoefficients.add((double)60);}}
>  {{  timeCoefficients.add((double)1000);}}
>  {{  timeCoefficients.add((double)1000);}}
>  {{  timeCoefficients.add((double)1000);}}
> {{}}}
> whilst
> {{const list<double> timeCoefficients = [24.0, 60.0, 60.0, 1000.0, 1000.0, 1000.0]}}
> compiles to
> {{public static final java.util.List<java.lang.Double> timeCoefficients = new java.util.ArrayList<java.lang.Double>();}}
> {{static {}}
> {{  timeCoefficients.add(24);}}
> {{  timeCoefficients.add(60);}}
> {{  timeCoefficients.add(60);}}
> {{  timeCoefficients.add(1000);}}
> {{  timeCoefficients.add(1000);}}
> {{  timeCoefficients.add(1000);}}
> {{}}}
> which leads to an error.
> When I modified this line as follows
> {{const list<double> timeCoefficients = [24.1, 60.1, 60.1, 1000.1, 1000.1, 1000.1]}}
> this line compiled to
> {{public static final java.util.List<java.lang.Double> timeCoefficients = new java.util.ArrayList<java.lang.Double>();}}
> {{static {}}
> {{  timeCoefficients.add(24.1);}}
> {{  timeCoefficients.add(60.1);}}
> {{  timeCoefficients.add(60.1);}}
> {{  timeCoefficients.add(1000.1);}}
> {{  timeCoefficients.add(1000.1);}}
> {{  timeCoefficients.add(1000.1);}}
> {{}}}
> My guess is that, even if I put {{.0}} at the end of each numeric constant, on the Java side, Thrift compiler considers them to be {{double}} and does no typecasts. However, the {{.0}} s are getting lost somewhere and the items become integers in the generated Java code. Thus, when it comes to populating the array, Java cannot succeed. {{Double}} s cannot be unboxed to integer and Java thinks {{int}} and {{Double}} are not related.



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