In JavaScript, I wrote f(x,y,name,z)

but intended to write f(x,,z)

A long debugging session was required to discover that z was undefined.

I gave 4 params, but f expected only 3.

The 4th parameter defaulted to undefined.

A simple compiler-check (count parameters), would have caught this typo. Instead it caused a mystery.


I would guess that parameter defaulting was inserted into the language in-search-for user-friendliness.


User Friendliness

This is not user friendly.

Simple Checks

Full-blown type-checking would not have been necessary here.

Just parameter-counting.

Re-Structuring Semantics Checking?

Hmm, we use a parser to check for stupid errors.

We don’t waste time waiting for a full type-check, if the parser caught stupid errors.

Maybe a pre-check pass should be inserted between the parser and the full-blown semantics checker?

How does this affect language design and user-friendliness? And, gradual typing?

Gradual Compilation

Maybe languages shoud be structured to allow experimentation, then, whine about “not enough information (detail) to compile” later?

Gradual Compiling

See Also

Table of Contents as of Dec. 01 2021