Defined types esuser.h defines the following C data types: U_8, U_16, U_32, U_64 Unsigned 8-, 16-, 32-, and 64-bit integers I_8, I_16, I_32, I_64 Signed 8-, 16-, 32-, and 64-bit integers I_PTR, U_PTR Signed and Unsigned integer type capable of holder pointer-sized values BOOLEAN Either TRUE or FALSE (also defined) EsObject Pointer to a VA Smalltalk object EsVMContext Pointer to a low-level process information structure specific to a particular Smalltalk process EsBehavior Pointer to a kind of Behavior (for example, Class or Metaclass) EsGlobalInfo Pointer to an information structure global to all Smalltalk processes EsPrimitiveTable A Smalltalk user primitive table