How to define a macro with value via command line?

[db4]

I must be missing something but cppo -D VAL=1 test.ml doesn't work:

let x = VAL

is expanded into

#1 "test.ml"
let x =  
#1      
        =1

[mjambon]

The command line for that is cppo -D 'VAL 1'. If I remember correctly, it was simpler to implement that way so I didn't bother supporting the usual cpp syntax. In hindsight it was a bad decision.

[db4]

I see. But maybe to support both -D 'VAL 1' and -D VAL=1? It shouldn't be that hard.

And it would be great if the syntax was mentioned in the docs.

[mjambon]

I added an example to the command-line help.

I'm hesitant to support the = syntax. Reasons are:

• supporting two syntaxes for the same thing isn't great
• it's inconsistent with the syntax used inside files, where no equal sign is used
• it introduce an incompatibility, e.g. -D 'EQ =' has now a new meaning

None of this is a big deal. Maybe we can support both syntaxes but deprecate the space-based syntax.