combine stuff - doesn't work

schala-lang/language/src/parser.rs

@@ -219,12 +219,29 @@ mod thing {
   use crate::builtin::Builtin;
 
   use combine::parser::range::{range, take_while1};
-  use combine::parser::repeat::sep_by;
+  use combine::parser::repeat::{many1, sep_by};
+  use combine::Stream;
   use combine::*;
 
+  fn number_literal<I>(input: &str) -> impl Parser<I, Output=u64>
+    where I: Stream<Token = char>, I::Error: ParseError<I::Token, I::Range, I::Position> {
+
+    use combine::parser::char::digit;
+
+    many1(digit())
+      .flat_map(|digits: Vec<char>| {
+        //let num_str: String = digits.into_iter().filter_map(|x| x).collect();
+        let num_str: String = digits.into_iter().collect();
+        u64::from_str_radix(&num_str, 10)
+      })
+  }
+
+
   pub fn perform_parsing(input: &str) -> String {
-    let identifier = take_while1(|c: char| c.is_alphabetic());
-    let mut parser = sep_by(identifier, range(", "));
+    use combine::parser::char::char;
+    //let identifier = take_while1(|c: char| c.is_alphabetic());
+    //let mut parser = sep_by(identifier, range(", "));
+    let parser = sep_by(char(','), number_literal);
     let result: Result<(Vec<&str>, &str), _> = parser.easy_parse(input);
     format!("{:?}", result)
   }