I’m following the example in the book (http://pharobooks.gforge.inria.fr/PharoByExampleTwo-Eng/latest/PetitParser.pdf <http://pharobooks.gforge.inria.fr/PharoByExampleTwo-Eng/latest/PetitParser.pdf>, pp. 9-10) with a slight modification. I believe that the example evaluates things that have the same precedence from right-to-left (is that correct?). I’ve tried to adjust things so that it evaluates from left to right, but get an error. Any advice?
James | number term prod prim start | number := #digit asParser plus flatten ==> [ :str | str asNumber ]. term := PPDelegateParser new. prod := PPDelegateParser new. prim := PPDelegateParser new. term setParser: (term memoized , $+ asParser trim , prod ==> [ :nodes | nodes first + nodes last ]) / prod. prod setParser: (prim , $* asParser trim , prod ==> [ :nodes | nodes first * nodes last ]) / prim. prim setParser: ($( asParser trim , term , $) asParser trim ==> [ :nodes | nodes second ]) / number. start := term end. start parse: '1 + 2'
