Remove gensym, inc and or from step files.

[jackhill/mal.git] / crystal / step9_try.cr

diff --git a/crystal/step9_try.cr b/crystal/step9_try.cr
index 4853cc8..455c31e 100755 (executable)
--- a/crystal/step9_try.cr
+++ b/crystal/step9_try.cr
@@ -87,6 +87,7 @@ module Mal
   def macro_call?(ast, env)
     list = ast.unwrap
     return false unless list.is_a? Mal::List
+    return false if list.empty?
 
     sym = list.first.unwrap
     return false unless sym.is_a? Mal::Symbol
@@ -136,7 +137,10 @@ module Mal
     # 'next' in 'do...end' has a bug in crystal 0.7.1
     # https://github.com/manastech/crystal/issues/659
     while true
-      return eval_ast(ast, env) unless ast.unwrap.is_a? Mal::List
+      list = ast.unwrap
+
+      return eval_ast(ast, env) unless list.is_a? Mal::List
+      return ast if list.empty?
 
       ast = macroexpand(ast, env)
 
@@ -207,7 +211,7 @@ module Mal
       when "macroexpand"
         macroexpand(list[1], env)
       when "try*"
-        catch_list = list[2].unwrap
+        catch_list = list.size >= 3 ? list[2].unwrap : Mal::Type.new(nil)
         return eval(list[1], env) unless catch_list.is_a? Mal::List
 
         catch_head = catch_list.first.unwrap
@@ -244,7 +248,6 @@ REPL_ENV.set("eval", Mal::Type.new ->(args : Array(Mal::Type)) { Mal.eval(args[0
 Mal.rep "(def! not (fn* (a) (if a false true)))"
 Mal.rep "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))"
 Mal.rep "(defmacro! cond (fn* (& xs) (if (> (count xs) 0) (list 'if (first xs) (if (> (count xs) 1) (nth xs 1) (throw \"odd number of forms to cond\")) (cons 'cond (rest (rest xs)))))))"
-Mal.rep "(defmacro! or (fn* (& xs) (if (empty? xs) nil (if (= 1 (count xs)) (first xs) `(let* (or_FIXME ~(first xs)) (if or_FIXME or_FIXME (or ~@(rest xs))))))))"
 
 argv = Mal::List.new
 REPL_ENV.set("*ARGV*", Mal::Type.new argv)
@@ -267,7 +270,9 @@ end
 while line = Readline.readline("user> ", true)
   begin
     puts Mal.rep(line)
+  rescue e : Mal::RuntimeException
+    STDERR.puts "Error: #{pr_str(e.thrown, true)}"
   rescue e
-    STDERR.puts e
+    STDERR.puts "Error: #{e}"
   end
 end