TypeScript Language Specification v1.5

When an identifier is resolved as a TypeName (section 3.7.2), only classes, interfaces, enums, and type
parameters are considered and other entities in scope are ignored.
When an identifier is resolved as a ModuleName (section 3.7.2), only modules are considered and other
entities in scope are ignored.
When an identifier is resolved as a PrimaryExpression (section 4.3), only instantiated modules (section
10.1), classes, enums, functions, variables, and parameters are considered and other entities in scope are
ignored.
Note that class and enum members are never directly in scope—they can only be accessed by applying
the dot ('.') operator to a class instance or enum object. This even includes members of the current
instance in a constructor or member function, which are accessed by applying the dot operator to this.
As the rules above imply, locally declared entities in an internal module are closer in scope than exported
entities declared in other module declarations for the same internal module. For example:
var x = 1;
module M {
export var x = 2;
console.log(x); // 2
}
module M {
console.log(x); // 2
}
module M {
var x = 3;
console.log(x); // 3
}
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