On 27/01/14 11:05, Alain Williams wrote:
* there are a few special values that are currently case insenitive, eg: NULL, TRUE.
I would suggest that they only be recognised in upper case, eg: null would be
invalid. This fits with the meme of constant names being in upper case.
I'd prefer lowercase, myself, but I do think we need consistency in case for language keywords as well as identifiers. Perhaps having everything lowercase.
* transition, there must be a lot of code that has (accidental) case
inconsistencies in function/variable/... names. If PHP were not a dynamic
language (eg C) then this change would be caught at compile time. In PHP a case
inconsistency is only found when the code is executed. Programs can contain
blocks of code that are rarely executed - think: rare error recovery.
Something that would help with transition is the option to force variables to
be declared. If a variable is then used without being declared an error is raised.
We currently have the problem as illustrated below:
$foo = 'bar';
echo "foo=$f00";
With case insensitivity this problem will become worse.
What I propose is something like perl's 'use strict'. This causes a compilation
error if a variable is used that has not been defined. This pragma applies only
for the compilation module that it is in; ie it does not apply to 'include'd
files and so can be done on a module by module basis.
The way that I suggest that we do this is by using the existing keyword 'var'. Eg:
var $foo = 'bar';
or
var $foo;
If 'var' is seen in a module, then use of any variables below MUST be for
variables that have been declared.
OK: that is the general idea, details need working on.
Note that the use of 'var' to declare variables is OPTIONAL, only use it if you
want to.