I try to translate a DSL to another language. Parsing the source file into ATerm is okay, but rewriting fails and I try to find out where the error is. Rule genPcd is defined. And to my knowledge, pp_java and so
on may be related to tools such as ast2abox and abox2text. So how can I locate errors ?

PS: The transformation is developed with libjava-front and libaspectj-front. To be specific, the DSL
extends Java and is transformed to AspectJ with the help of Spoofax.

Console output:

EventCJ: rewriting failed, trace:
 generate_java_0_0
 to_java_0_0
 map_1_0
 map_1_0
 genPcd_0_3
 pp_java_string_0_0
 pp_java5_to_string_0_0
 box2text_string_0_1
 abox2text_0_1
 abox2text_1_2
 abox2text_list_1_2

Asked by Guido Wachsmuth on 31 July 2013 at 05:40

The trace tells us that pretty-printing fails. Typically, this is caused by an erroneous AST, which contains terms which cannot be handled by the pretty-printer. To find such terms, you can use the following code:

   output := <the-pp-strategy> input
<+ <bottomup(try(not(is-string) ; not(is-list) ; not(the-pp-strategy) ; debug(!"cannot pp "))); fail> input

Make sure to replace the-pp-strategy with your actual pretty-printing strategy. The second line performs a bottomup traversal and tries to find terms which cannot be pretty-printed and reports those terms to the console (debug).

Answered by Guido Wachsmuth on 31 July 2013 at 05:47