icode: shortcut in icode generation of 'for x in [y..z]'

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/src/syntax/icode_generation.nit b/src/syntax/icode_generation.nit
index 7bb32be..af61111 100644 (file)
--- a/src/syntax/icode_generation.nit
+++ b/src/syntax/icode_generation.nit
@@ -777,13 +777,34 @@ end
 redef class AForExpr
        redef fun generate_icode(v)
        do
-               var expr_type = n_expr.stype
-
-               # Get iterate
-               var meth_iterate = v.visitor.get_method(expr_type, once "iterate".to_symbol)
+               var ne = n_expr
+               var expr_type = ne.stype
+               var tint = v.visitor.type_int
+               var meth # The method that call the closure
+               var args # The arguments of meth
+
+               if ne isa ARangeExpr and expr_type == v.visitor.type_range(tint) then
+                       # Shortcut. No Range[Int] object allocated.
+                       # 'for x in [y..z] do' become 'y.enumerate_to(z) !each(x) do'
+                       # 'for x in [y..z[ do' become 'y.enumerate_before(z) !each(x) do'
+                       # And both methods may be inlined
+                       args = [v.generate_expr(ne.n_expr), v.generate_expr(ne.n_expr2)]
+                       if ne isa ACrangeExpr then
+                               meth = v.visitor.get_method(tint, once "enumerate_to".to_symbol)
+                       else
+                               assert ne isa AOrangeExpr
+                               meth = v.visitor.get_method(tint, once "enumerate_before".to_symbol)
+                       end
+               else
+                       # Standard way.
+                       # 'for x in e do' become 'e.iterate !each(x) do'
+                       # Some iterate methods may be inlined (eg. the Array one)
+                       meth = v.visitor.get_method(expr_type, once "iterate".to_symbol)
+                       args = [v.generate_expr(n_expr)]
+               end
 
                # Build closure
-               var iclos = meth_iterate.signature.closures.first.signature.generate_empty_iclosuredef(v)
+               var iclos = meth.signature.closures.first.signature.generate_empty_iclosuredef(v)
                var old_seq = v.seq
 
                var seq = new ISeq
@@ -800,7 +821,7 @@ redef class AForExpr
 
                # Call closure
                v.seq = seq
-               v.add_call(meth_iterate, [v.generate_expr(n_expr)], [iclos])
+               v.add_call(meth, args, [iclos])
 
                v.seq = old_seq
                return null