Var declaration checking

[wilco2009]

Please, Could be possible to add an command option to require declare all variables.
I think, not declared variables is the source of bugs more difficult to find.
The problem is worse when you consider that BASIC is case sensitive.

[boriel]

This is "pending" task; it will eventually be implemented. It's the flag Explicit (see -lang qb)
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I will implement it both as
#pragma option explicit

and as a command line flag: --option explicit

What do you think?

[wilco2009]

Perfect!
I think the sintaxis is very clear.
When you have the option implemented, I'll start using it.
As Pascal enthusiast, I think it should be active by default.

[boriel]

Perfect!
I think the sintaxis is very clear.
When you have the option implemented, I'll start using it.
As Pascal enthusiast, I think it should be active by default.

So do I. ZX BASIC started as a project with high Sinclair BASIC compatibility, but with the time I started to diverge in order to achieve higher performance. For compatibility, people should always use the --sinclair flag.

[boriel]

Okay, I think I've implemented this one. Download 1.3.0s959.
Use:

Code:

zxb --explicit <yourprogram.bas>

To compile it.
The following program:

Code:

LET a = 5

Should trigger an error if you compile it with --explicit option.
You can also use #pragmas in source code, which is a way to change compiling options from within the source code.

Code:

REM The following line will override command line parameters
#pragma explicit = True
LET a = 5

NOTE: The OPTION command won't be implemented (it's being deprecated even in FreeBASIC). #pragmas are used in C/C++ compilers, and FreeBASIC. So ZXBASIC will support them too.

[wilco2009]

It's great!

Many thanks. Both options are checked and are working perfectly.