Unless you're talking about a large piece of software composed entirely of single character functions and variable names, I pretty much disagree. Verbose variable names do not magically teach those reading a piece of code how it works, simultaneously they tend to make it impossible to write many kinds of expressions concisely, and consequently they regularly damage the readability of more complex pieces of code (e.g. arithmetic expressions involving 3 or more terms).
The same goes for symbolic constants. Sometimes (but not exactly "often"), use of numeric literals can vastly improve the maintainability of some code, assuming the reader understands how to maintain it in the first instance.
As for increasing reader comprehension, carefully thought out comments are a better mechanism by far.
In this case, it is sufficient to know that the file is a compiler/interpreter for its entirety to make sense, assuming the reader has implemented (or at least understood the principles behind) a compiler/interpreter in their past. Expanding the function/variable names, splitting "complicated" expressions out into their own functions, etc., does not magically improve the uninitiated's chance of understanding what is going on
The same goes for symbolic constants. Sometimes (but not exactly "often"), use of numeric literals can vastly improve the maintainability of some code, assuming the reader understands how to maintain it in the first instance.
As for increasing reader comprehension, carefully thought out comments are a better mechanism by far.
In this case, it is sufficient to know that the file is a compiler/interpreter for its entirety to make sense, assuming the reader has implemented (or at least understood the principles behind) a compiler/interpreter in their past. Expanding the function/variable names, splitting "complicated" expressions out into their own functions, etc., does not magically improve the uninitiated's chance of understanding what is going on