1. A method for detection of errors in computer program code, comprising the steps of: computing typeprints of data types contained in the computer program code, by combining a hash code corresponding to each data type with an is-partial bit that identifies whether the data type is specified only partially in the computer program code; checking consistency of declarations of program entities contained in the computer program code, by performing comparisons of data types corresponding to common program entities contained in the computer program code in order to identify differing data types that improperly correspond to a common program entity; and exempting from consistency checking any data type whose typeprint has an is-partial bit, whereby false indications of inconsistency of partially specified data types are avoided.