The latter was the reasoning and in fact apparently aD and OpenACS folk were unaware of "eq"/"ne". I know I was until you pointed this out - I've been using "string equal" ...
Sounds like we could clean up our code a bit. Also our general way of writing "set" expressions is sub-optimal, I know folks in general seem to realize it's good practice to surround your "if" expr in curly-braces, but I'd never thought about the fact that the same is true of "set". We aren't getting full speed from the bytecode compiler it appears:
"Enclose expressions in braces for the best speed and the smallest storage requirements. This allows the Tcl bytecode compiler to generate the best code.
As mentioned above, expressions are substituted twice: once by the Tcl parser and once by the expr command. For example, the commands
set a 3
set b {$a + 2}
expr $b*4
return 11, not a multiple of 4. This is because the Tcl parser will first substitute $a + 2 for the variable b, then the expr command will evaluate the expression $a + 2*4.
Most expressions do not require a second round of substitutions. Either they are enclosed in braces or, if not, their variable and command substitutions yield numbers or strings that don't themselves require substitutions. However, because a few unbraced expressions need two rounds of substitutions, the bytecode compiler must emit additional instructions to handle this situation. The most expensive code is required for unbraced expressions that contain command substitutions. These expressions must be implemented by generating new code each time the expression is executed."
The "gotcha" seems awful until you realize that AFAIK we've never been bit by it in "if" statements ...
