[antlr-interest] Disambiguating simple grammar – could anyone help?

[Tomasz Jastrzebski]

Hello developers,
I cannot figure out how to disambiguate the following grammar using syntactic predicate, so the range rule takes precedence over the offset rule.
Could anyone advice? I prefer to keep separate range and offset rules because of the custom AST tree construction.
Thanks for any pointers,
Thomas

grammar test;
program : (expression)* ;
expression
 :
   Identifier ((range) => range)?
 | offset
 ;
range : Integer ('-' Integer)? ;
offset : ('+' | '-') Integer ;
Identifier : ('a'..'z')+ ;
Integer : ('0'..'0')+ ;
WhiteSpace : (' ' | '\t' | '\r\n' | '\r')+ { $channel=HIDDEN; };


      
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