Better programming languages let us do more -- and less

We tend to think that better programming languages let us programmers do more. Which is true, but it is not the complete picture.

Better languages also let us do less. They remove capabilities. In doing so, they remove the possibility for errors.

PL/I was better than COBOL and FORTRAN because it let us write free-form source code. In COBOL and FORTRAN, the column in which code appeared was significant. The restrictions were from the technology of the time (punch cards) but once in the language they were difficult to remove.

BASIC was better than FORTRAN because it eliminated FORMAT specifications. FORMAT specifications were necessary to parse input data and format output data. They were precise, opaque, and easy to get wrong. BASIC, with no such specifications, removed the possibility of errors from such specifications. BASIC also fixed the DO loops of FORTRAN and removed restrictions on subscript form. (In FORTRAN, a subscript could not be an arbitrary expression but had to have the form A*B+C. Any component could be zero and omitted so A+C was allowed, as was A*B. But you could not use A+B+C or A/2.)

Pascal was better than BASIC because it limited the use of GOTO statements. In BASIC, you could use a GOTO to transfer control to any other part of the program, including in and out of loops or subroutines. It made for "spaghetti code" which was difficult to understand and debug. Pascal put an end to that, with a constrained form of GOTO.

Java eliminated the need for the explicit 'delete' or 'free' operations on allocated memory. You cannot forget the 'delete' operation -- you can't write one at all! The internal garbage collector recycles memory. In Java, it is much harder to create memory leaks than in C++ and C.

Python forces us to consider indentation as part of the code. In C, C++, Java, and C#, you can write:

initialize();

if (some_condition)
    do_something();
    do_another_thing();

complete_the_work();

But the code acts in a way you may not expect. Python's use of indentation to specify code organization makes the code clearer. The Python code:

initialize()

if some_condition:
    do_something()
    do_another_thing()

complete_the_work()

does what you expect.

New programming languages do provide new capabilities. (Often, they are refinements to constructs and concepts that were implemented roughly in earlier programming languages.) A new programming language is a combination of new things we can do and old things we no longer need to do.

When considering a new language (or reviewing the current language for a project), keep in mind not only the things that a new language lets you do, but also the things that it won't let you do.