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delimiter = ExprDelim;
void ExprDelim();
ExprDelim : "[ \n\r\t]*";
// Simple expression evaluation with variables.
Int SExpr(Map<Str, Int> vars);
Int SProd(Map<Str, Int> vars);
Int SAtom(Map<Str, Int> vars);
SExpr => a : SProd(vars) a;
SExpr => +(a, b) : SExpr(vars) a, "\+", SProd(vars) b;
SProd => a : SAtom(vars) a;
SProd => *(a, b) : SProd(vars) a, "\*", SAtom(vars) b;
SAtom => toInt(v) : "[0-9]+" v;
SAtom => get(vars, name): "[a-z]+" name;
// Test so that empty rules still work.
void SEDelim();
void SEmpty();
void SParen();
SEDelim : " *";
SEmpty : SEDelim;
SParen : "(" - SEDelim - SEmpty - SEDelim - ")";
// A simplified version of lang.bs.SSkipContent, which crashed earlier.
void Skip();
Skip : " *" - Skip - " *" - Skip - " *";
Skip : "[^{}]*";
Skip : "{" - Skip - "}";
// A simplified version of repeated whitespace rules, which caused the GLR parser to fail earlier.
void MultiWS();
MultiWS : MultiWSB - ExprDelim - "b";
void MultiWSB();
MultiWSB : "a" - ExprDelim;
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