8. A method, comprising: transforming a program from a first language to a second language using a compiler for a third language and data type representation conversion without helper classes, wherein said transforming step includes: generating, by a compiler for the first language, an abstract syntax tree; converting, by the compiler for the third language, the first abstract syntax tree to a given abstract syntax tree of the compiler for the third language using a conversion table; when a compilation error occurs in the compiler for the third language, generating therein a special node for error processing in a second abstract syntax tree of the compiler of the second language and storing an error token indicating information of the compilation error in the special node; and when unparsing by the compiler for the second language, outputting the error token stored in the special node.
8. A method, comprising: transforming a program from a first language to a second language using a compiler for a third language and data type representation conversion without helper classes, wherein said transforming step includes: generating, by a compiler for the first language, an abstract syntax tree; converting, by the compiler for the third language, the first abstract syntax tree to a given abstract syntax tree of the compiler for the third language using a conversion table; when a compilation error occurs in the compiler for the third language, generating therein a special node for error processing in a second abstract syntax tree of the compiler of the second language and storing an error token indicating information of the compilation error in the special node; and when unparsing by the compiler for the second language, outputting the error token stored in the special node. 9. The method of claim 8 , further comprising generating optimized code by the compiler for the second language.