add if/else

bin/main.ml

@@ -1,6 +1,6 @@
 let () =
   try
-    let modl = Spice.parse "fun main(x) { val y = x + 2  IO.print(y * x) }" in
+    let modl = Spice.parse "fun main(x) { val y = x * 2 val z = if(y > x) y else 1 }" in
     Format.fprintf Format.std_formatter "%a\n" Spice.Syn.pp_modl modl
   with Spice.Error.Error err ->
     Format.fprintf Format.err_formatter "error: %a\n" Spice.Error.pp err

lib/lexer.mll

@@ -9,6 +9,8 @@ let _ = begin
     Hashtbl.add keywords "val" Kw_val;
     Hashtbl.add keywords "fun" Kw_fun;
     Hashtbl.add keywords "obj" Kw_obj;
+    Hashtbl.add keywords "if" Kw_if;
+    Hashtbl.add keywords "else" Kw_else;
 end
 
 let is_digit ch = ch >= '0' && ch <= '9'

lib/parser.mly

@@ -14,6 +14,8 @@
 %token Kw_val "val"
 %token Kw_fun "fun"
 %token Kw_obj "obj"
+%token Kw_if "if"
+%token Kw_else "else"
 
 %token EOF
 %start <Syn.modl> modl
@@ -21,10 +23,6 @@
 %{
     open Syn
 
-    let maybe_call prefix = function
-      | None -> Path prefix
-      | Some args -> Call (prefix, args)
-
     let infix_base e0 = (e0, [])
     let infix_app (e0, ops) op e2 = (e0, (op, e2) :: ops)
 
@@ -46,8 +44,10 @@ item:
 
 exp:
   | e = infixexp { resolve_fixity e }
+  | "if"; "("; e1 = exp; ")"; e2 = exp; "else"; e3 = exp { If (e1, e2, e3) }
   | "fun"; p = params; e = exp { Fun (p, e) }
   | "obj"; b = block { Obj b }
+  | b = block { Scope b }
 
 infixexp:
   | e0 = singleexp { infix_base e0 }
@@ -55,8 +55,8 @@ infixexp:
 
 singleexp:
   | i = Int { Literal (Int i) }
-  | p = path; a = option(args) { maybe_call p a }
-  | b = block { Scope b }
+  | p = path { Path p }
+  | f = path; a = args { Call (f, a) }
 
 path:
   | x = Name { Var x }

lib/syn.ml

@@ -34,6 +34,7 @@ and exp =
   | Path of path
   | Call of path * exp list
   | Binop of binop * exp * exp
+  | If of exp * exp * exp
   | Fun of params * exp
   | Obj of block
   | Scope of block
@@ -83,6 +84,11 @@ let rec pp_exp ppf = function
   | Path (Var x) -> pf ppf "{\"var\":%S}" x
   | Path (Ele (e, x)) -> pf ppf "{\"ele\":%a,\"field\":%S}" pp_exp e x
   | Call (fn, args) -> pf ppf "{\"call\":%a}" (pp_list pp_exp) (Path fn :: args)
+  | If (ec, et, ee) ->
+      pf ppf "{\"if\":%a,\"then\":%a,\"else\":%a}"
+        pp_exp ec
+        pp_exp et
+        pp_exp ee
   | Binop (op, e1, e2) ->
       pf
         ppf