Foundations of Software - LAMP - EPFL

Evaluate by FoldLeft
We can solve this problem by delaying reduction until all elements of a
repetition have been parsed and then performing a fold left on the list:
def expr : Parser[Int] =
term ˜ rep (”+” ˜ term | ”−” ˜ term) ˆˆ reduceList
def term : Parser[Int] =
factor ˜ rep (”∗” ˜ factor | ”/” ˜ factor) ˆˆ reduceList
def factor : Parser[Int] =
”(” ˜> expr