advpl.hs

Stmt = _ 'function'i _ name:Name _ '(' ')' _ EOL _ body:Stmt+ _ {
	return 'var name ' + name + ' = function () {' + body + '}'
} / _ 'return' _ e:Expression _ {
	return 'return ' + e
}

Expression
  = head:Term tail:(_ ("+" / "-") _ Term)* {
      return tail.reduce(function(result, element) {
        if (element[1] === "+") { return result + element[3]; }
        if (element[1] === "-") { return result - element[3]; }
      }, head);
    }

Term
  = head:Factor tail:(_ ("*" / "/") _ Factor)* {
      return tail.reduce(function(result, element) {
        if (element[1] === "*") { return result * element[3]; }
        if (element[1] === "/") { return result / element[3]; }
      }, head);
    }

Factor
  = "(" _ expr:Expression _ ")" { return expr; }
  / Integer

Integer "integer"
  = _ [0-9]+ { return parseInt(text(), 10); }

Name "name"
  = _ x:[a-zA-Z] xs:[a-zA-Z0-9]* { return x + xs.join('') }

_ "whitespace"
  = [ \t]*

EOL "eol"
  = [\r\n]+