Property Accesses in Dynamically Typed Programming Languages

A code generator may emit a direct access code for accessing a property of an object under conditions which promote type safety in a dynamically typed programming language. The direct access code accesses a value of the property using a hard-coded offset into the object's memory region. In some cases, the direct access code accesses the value after a single type check that guards a sequence of property accesses, including at least one prior sequence member. In some cases, type check code compares an object's type to a designated guard type of an equivalent type cache. An object type may be checked for property-specific access equivalence with types in the equivalent type cache by using a property equivalence record which is associated with the equivalent type cache. When types are not access-equivalent with regard to a property, type safety is preserved by emitting nondirect access code for accessing the property.