syntax: Split SubVariableContext and CastVariableContext

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

diff --git a/src/syntax/typing.nit b/src/syntax/typing.nit
index aa3581c..637ea2d 100644 (file)
--- a/src/syntax/typing.nit
+++ b/src/syntax/typing.nit
@@ -146,13 +146,13 @@ private class VariableContext
        # Build a new VariableContext
        meth sub: SubVariableContext
        do
-               return new SubVariableContext.with_prev(self, null, null)
+               return new SubVariableContext.with_prev(self)
        end
 
        # Build a nested VariableContext with new variable information
        meth sub_with(v: Variable, t: MMType): SubVariableContext
        do
-               return new SubVariableContext.with_prev(self, v, t)
+               return new CastVariableContext.with_prev(self, v, t)
        end
 
        init
@@ -164,8 +164,6 @@ end
 private class SubVariableContext
 special VariableContext
        readable attr _prev: VariableContext
-       attr _variable: Variable
-       attr _var_type: MMType
 
        redef meth [](s)
        do
@@ -178,6 +176,23 @@ special VariableContext
 
        redef meth stype(v)
        do
+               return prev.stype(v)
+       end
+
+       init with_prev(p: VariableContext)
+       do
+               init
+               _prev = p
+       end
+end
+
+private class CastVariableContext
+special SubVariableContext
+       attr _variable: Variable
+       attr _var_type: MMType
+
+       redef meth stype(v)
+       do
                if _variable == v then
                        return _var_type
                end
@@ -186,8 +201,7 @@ special VariableContext
 
        init with_prev(p: VariableContext, v: Variable, t: MMType)
        do
-               init
-               _prev = p
+               super(p)
                _variable = v
                _var_type =t
        end