Allow multiple patterns to be specified

Author: MatheusRich

spec/e2e/match/valid.lit

@@ -1,21 +1,28 @@
 fn number_as_word do match it {
   2 then "two"
   1 then "one"
+  3, 4 then "three or four"
   _ then "too big"
 }
 
 debug(number_as_word(1)) # expect: "one"
 debug(number_as_word(2)) # expect: "two"
-debug(number_as_word(3)) # expect: "too big"
+debug(number_as_word(3)) # expect: "three or four"
+debug(number_as_word(4)) # expect: "three or four"
+debug(number_as_word(5)) # expect: "too big"
 
 fn word_to_number do match it {
+  "zero",
+  "none", then 0
   "one" then 1
   "two" then 2
-  _ then 0
+  _ then -1
 }
 debug(word_to_number("one")) # expect: 1
 debug(word_to_number("two")) # expect: 2
-debug(word_to_number("other")) # expect: 0
+debug(word_to_number("zero")) # expect: 0
+debug(word_to_number("none")) # expect: 0
+debug(word_to_number("other")) # expect: -1
 
 fn is_empty do match it {
   [] then true

src/lit/parser.cr

@@ -326,10 +326,18 @@ module Lit
       branches = [] of Tuple(Expr, Expr)
 
       until check(TokenType::RIGHT_BRACE) || at_end?
-        pattern = expression
+        patterns = [expression] of Expr
+        while match?(TokenType::COMMA)
+          ignore_newlines
+          # Allow trailing comma by checking if we're at the end of the match block
+          break if check(TokenType::THEN)
+          patterns << expression
+        end
+
         consume(TokenType::THEN, "I was expecting 'then' after the match pattern.")
 
-        branches << {pattern, expression}
+        body = expression
+        branches += patterns.map { |p| {p, body}.as(Tuple(Expr, Expr)) }
         consume_line("I was expecting a newline after the match case.")
 
         ignore_newlines