What is a "real" syntax tree? I wonder if the intent was "concrete" (the contrast to an abstract syntax tree), or if it's meant colloquially (as in "you really get a syntax tree" or "you get an actual syntax tree") rather than as a technical term.

I think OP means that it will parse EDIFACT with the tree structure it actually has in its specification, instead of a simple list of messages like many people do.

EDIFACT normally has (possibly repeating, possibly nesting) segment groups and a lot of code trying to handle EDIFACT skips over that.