mmbuilder: detect type of some attributes

Allows to automaticaly determine the static type of some attributes assigned
where introduced. Works for literal Int, Char, Bool and String, as well as
"new" and boolean expressions.

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>

diff --git a/src/syntax/mmbuilder.nit b/src/syntax/mmbuilder.nit
index 765c26b..636ef1f 100644 (file)
--- a/src/syntax/mmbuilder.nit
+++ b/src/syntax/mmbuilder.nit
@@ -1090,11 +1090,15 @@ redef class AAttrPropdef
        redef fun accept_property_verifier(v)
        do
                super
-               var t: MMType
+               var t: nullable MMType = null
                if n_type != null then
                        var t0 = n_type.get_stype(v)
                        if t0 != null then t = t0 else return
-               else
+               else if n_expr != null then
+                       t = n_expr.get_easy_stype(v)
+               end
+
+               if t == null then
                        v.error(self, "Not yet implemented: Attribute definition {prop.local_class}::{prop} requires an explicit type.")
                        return
                end
@@ -1108,7 +1112,7 @@ redef class AAttrPropdef
                        var m = _readmethod.as(not null)
                        m.signature = signature
                        process_and_check(v, m, (n_readable != null and n_readable.n_kwredef != null) or (n_id == null and n_kwredef != null), visibility_level)
-                       n_type.check_visibility(v, m)
+                       if n_type != null then n_type.check_visibility(v, m)
                end
                if n_writable != null or n_id == null then
                        var m = _writemethod.as(not null)
@@ -1118,7 +1122,7 @@ redef class AAttrPropdef
                                if n_writable == null then vl = 3 else vl = n_writable.n_visibility.level # write accessor has a specific visibility
                        end
                        process_and_check(v, m, n_writable != null and n_writable.n_kwredef != null, vl)
-                       n_type.check_visibility(v, m)
+                       if n_type != null then n_type.check_visibility(v, m)
                end
        end
 
@@ -1420,4 +1424,30 @@ redef class AExpr
        redef fun accept_class_builder(v) do end
        redef fun accept_property_builder(v) do end
        redef fun accept_property_verifier(v) do end
+
+       private fun get_easy_stype(v:PropertyVerifierVisitor) : nullable MMType do return null
+end
+
+redef class ABoolExpr
+       redef fun get_easy_stype(v) do return v.type_bool
+end
+
+redef class AStringExpr
+       redef fun get_easy_stype(v) do return v.type_string
+end
+
+redef class ACharExpr
+       redef fun get_easy_stype(v) do return v.type_char
+end
+
+redef class AIntExpr
+       redef fun get_easy_stype(v) do return v.type_int
+end
+
+redef class AFloatExpr
+       redef fun get_easy_stype(v) do return v.type_float
+end
+
+redef class ANewExpr
+       redef fun get_easy_stype(v) do return n_type.get_stype(v)
 end

diff --git a/tests/sav/test_attr_easy.sav b/tests/sav/test_attr_easy.sav
new file mode 100644 (file)
index 0000000..e6da479
--- /dev/null
+++ b/tests/sav/test_attr_easy.sav
@@ -0,0 +1,4 @@
+true false 12345 1.234500 asdf true
+an instance of B
+true true true true
+true true true true

diff --git a/tests/test_attr_easy.nit b/tests/test_attr_easy.nit
new file mode 100644 (file)
index 0000000..dfcbb6b
--- /dev/null
+++ b/tests/test_attr_easy.nit
@@ -0,0 +1,24 @@
+
+class B
+       redef fun to_s do return "an instance of B"
+end
+
+class A
+       var a = true
+       var b = false
+       var c = 12345
+       var d = 1.2345
+       var e = "asdf"
+       var f = new B
+       var g = new HashMap[Int,B]
+
+       var h = true or false
+
+       redef fun to_s do return "{a} {b} {c} {d} {e} {h}\n" +
+               "{f}\n" + 
+               "{a isa Bool} {b isa Bool} {c isa Int} {d isa Float}\n" +
+               "{e isa String} {f isa B} {not f isa A} {g isa HashMap[Int,B]}"
+end
+
+var a = new A
+print a