[logicallee]

>Here's the problem with that idea: How do you convert your abstract high-level description into a set of specific operations? First you need to parse your specification, and parsing natural language is already hard. [my emphasis]

If that were true it would be impossible to make a flow-chart based interface to a "compiler" that produces an executable based on the flowchart (without any keywords, variable names, etc). But plainly it is possible to make such a flowchart->executable compiler+visual IDE, so you are incorrect regarding the claim that the specification needs to be parsed lexically. Functionality does not depend on lexical parsing. It's that simple.