Compiler for evaluating Boolean expressions

摘要

An intelligent compiler particularly useful for evaluating Boolean expressions such as those associated with ladder structures. True/false paths are defined through the expressions. In a first pass for the code generation, the start code for examining each element is set out. In a second pass the relative offsets for branching from one element to the next element along both the true and false paths are filled in. In practice, execution time for evaluating ladder structures is reduced by an order of magnitude over prior techniques which use source code and an interpreter.