--- a/progs/comb1.scala Mon Nov 14 15:50:42 2016 +0000
+++ b/progs/comb1.scala Fri Dec 16 11:13:41 2016 +0000
@@ -92,14 +92,15 @@
// arithmetic expressions
lazy val E: Parser[String, Int] =
- (F ~ "*" ~ F) ==> { case ((x, y), z) => x * z } || F
+ (T ~ "+" ~ E) ==> { case ((x, y), z) => x + z } ||
+ (T ~ "-" ~ E) ==> { case ((x, y), z) => x - z } || T
+lazy val T: Parser[String, Int] =
+ ((F ~ "*" ~ T) ==> { case ((x, y), z) => x * z } || F)
lazy val F: Parser[String, Int] =
- ((T ~ "+" ~ T) ==> { case ((x, y), z) => x + z } ||
- (T ~ "-" ~ T) ==> { case ((x, y), z) => x - z } || T)
-lazy val T: Parser[String, Int] =
("(" ~ E ~ ")") ==> { case ((x, y), z) => y } || NumParser
-println(E.parse("1*2+3"))
+println(E.parse("4*2+3"))
+println(E.parse_all("4*2+3"))
println(E.parse("1 + 2 * 3"))
println(E.parse_all("(1+2)+3"))
println(E.parse_all("1+2+3")) // this is not parsed, because of