OpenEuphoria

1. Nested Multiline Comment

• Posted by eumini Jul 02, 2009
• 1109 views
• Last edited Jul 03, 2009

Dear Developers,

The new multi-line commenting feature has proven to be quite useful. I have a question as to how it was designed to behave when nested.

I recently did something like the following (basically from a C header file) expecting the whole thing to be ignored, but EU complains about the last item which is right after a nested c-type comment. I could put a "" before the nested comment (infact this happens to be one of those I forgot to treat that way), but wondered if this is possibly a bug or as intended.

Thanks.

'Debo

/* 

enum  
--gretl_opt_flags 
    OPT_NONE = 0, 
    OPT_A = 1 <<  0, 
    OPT_B = 1 <<  1, 
    OPT_C = 1 <<  2, 
    OPT_D = 1 <<  3, 
    OPT_E = 1 <<  4, 
    OPT_F = 1 <<  5, 
    OPT_G = 1 <<  6, 
    OPT_H = 1 <<  7, 
    OPT_I = 1 <<  8, 
    OPT_J = 1 <<  9, 
    OPT_K = 1 << 10, 
    OPT_L = 1 << 11, 
    OPT_M = 1 << 12, 
    OPT_N = 1 << 13, 
    OPT_O = 1 << 14, 
    OPT_P = 1 << 15, 
    OPT_Q = 1 << 16, 
    OPT_R = 1 << 17, 
    OPT_S = 1 << 18, 
    OPT_T = 1 << 19, 
    OPT_U = 1 << 20, 
    OPT_V = 1 << 21, 
    OPT_W = 1 << 22, 
    OPT_X = 1 << 23, 
    OPT_Z = 1 << 24, 
    OPT_Y = 1 << 25, /* added 2009-03-15 */ 
    OPT_UNSET = 1 << 30 
*/ 
 

3. Re: Nested Multiline Comment

• Posted by DerekParnell (admin) Jul 03, 2009
• 1111 views

The /* ... */ is intended not to be nested. The comment starts with /* and ends at the very next */ that it comes across.

The comment idea is intended to to help coders add comments to their code, and not explicitly intended to comment out valid code.

One way that you can do to comment out a large block of code is to use the ifdef facility.

For example:

ifdef COMMENT_OUT then 
enum  
--gretl_opt_flags 
    OPT_NONE = 0, 
    OPT_A = 1 <<  0, 
    OPT_B = 1 <<  1, 
    OPT_C = 1 <<  2, 
    OPT_D = 1 <<  3, 
    OPT_E = 1 <<  4, 
    OPT_F = 1 <<  5, 
    OPT_G = 1 <<  6, 
    OPT_H = 1 <<  7, 
    OPT_I = 1 <<  8, 
    OPT_J = 1 <<  9, 
    OPT_K = 1 << 10, 
    OPT_L = 1 << 11, 
    OPT_M = 1 << 12, 
    OPT_N = 1 << 13, 
    OPT_O = 1 << 14, 
    OPT_P = 1 << 15, 
    OPT_Q = 1 << 16, 
    OPT_R = 1 << 17, 
    OPT_S = 1 << 18, 
    OPT_T = 1 << 19, 
    OPT_U = 1 << 20, 
    OPT_V = 1 << 21, 
    OPT_W = 1 << 22, 
    OPT_X = 1 << 23, 
    OPT_Z = 1 << 24, 
    OPT_Y = 1 << 25, /* added 2009-03-15 */ 
    OPT_UNSET = 1 << 30 
end ifdef 
 

[/quote] By the way, probably coming in 4.1 we will have shift operators << and >> and enums that do binary increments, something like

enum by *2 
    OPT_NONE = 0, 
    OPT_A = 1,  -- #00000001 
    OPT_B, -- #00000002 
    OPT_C, -- #00000004 
    OPT_D, -- #00000008 
    OPT_E, -- #00000010 
  . . . etc ... 
    OPT_UNSET = 1 << 30 

5. Re: Nested Multiline Comment

• Posted by DerekParnell (admin) Jul 03, 2009
• 1155 views

LOL ... not exactly. A number of enhancements have been suggested that we have decided not to put into 4.0. Instead we will wait until after that big bang has settled down a bit.

Have a look at Sourceforge to see the recorded suggestions so far. Of course, you can always add to this list.

7. Re: Nested Multiline Comment

• Posted by jimcbrown (admin) Jul 03, 2009
• 1095 views

/* 

sequence name = "John" /* testing */ 
integer age = 133 
*/ 

It would be very convinient to have. I can't tell you how many times I've used those in C or Java files, only to have the compile fail because the code I was commenting out, had a multiline comment that was one line long. I would be for this unless someone gave a compelling reason why it was a bad idea.

And Java doesn't have even have ifdefs.....