Change the log level to be an enum rather than an int

This allows for eliminating a match check.

src/libsyntax/ast.rs

@@ -309,6 +309,10 @@ enum blk_check_mode { default_blk, unchecked_blk, unsafe_blk, }
 type expr = {id: node_id, callee_id: node_id, node: expr_, span: span};
 // Extra node ID is only used for index, assign_op, unary, binary
 
+#[auto_serialize]
+enum log_level { error, debug, other }
+// 0 = error, 1 = debug, 2 = other
+
 #[auto_serialize]
 enum alt_mode { alt_check, alt_exhaustive, }
 
@@ -354,7 +358,7 @@ enum expr_ {
     expr_break(option<ident>),
     expr_again(option<ident>),
     expr_ret(option<@expr>),
-    expr_log(int, @expr, @expr),
+    expr_log(log_level, @expr, @expr),
 
     /* just an assert */
     expr_assert(@expr),

src/libsyntax/parse/parser.rs

@@ -947,7 +947,7 @@ struct parser {
             let lvl = self.parse_expr();
             self.expect(token::COMMA);
             let e = self.parse_expr();
-            ex = expr_log(2, lvl, e);
+            ex = expr_log(ast::other, lvl, e);
             hi = self.span.hi;
             self.expect(token::RPAREN);
         } else if self.eat_keyword(~"assert") {

src/libsyntax/print/pprust.rs

@@ -1309,10 +1309,10 @@ fn print_expr(s: ps, &&expr: @ast::expr) {
         }
       }
       ast::expr_log(lvl, lexp, expr) => {
-        match check lvl {
-          1 => { word_nbsp(s, ~"log"); print_expr(s, expr); }
-          0 => { word_nbsp(s, ~"log_err"); print_expr(s, expr); }
-          2 => {
+        match lvl {
+          ast::debug => { word_nbsp(s, ~"log"); print_expr(s, expr); }
+          ast::error => { word_nbsp(s, ~"log_err"); print_expr(s, expr); }
+          ast::other => {
             word_nbsp(s, ~"log");
             popen(s);
             print_expr(s, lexp);