#829 plus/minus need a space before numbers to be recognized as arithmetic operator

[Mickey White]

New member, TriAttack, has discovered a syntax compile error for the compute statement, see: [bd54dff202].

COMPUTE Num4 = (3/2)+3
Where Num4 is declared as PIC 9V9
Both the compiler and the parser in OCIDE say "Syntax Error, unexpected literal" on the line. However, when I input
COMPUTE Num4 = 3+(3/2)
The program works perfectly fine. Following the traditional order of operations, both lines should lead to the same value for Num4, 4.5, due to the parentheses.

The first compute statement will work if there are spaces on both sides of the plus sign.
Version 3.1.2.0

[Mickey White]

C:\GnuCOBOL>cobc -x compute1.cbl
compute1.cbl:18: error: syntax error, unexpected Literal

C:\GnuCOBOL>cobc -x compute2.cbl

C:\GnuCOBOL>compute2
4.5
3.5

[Simon Sobisch]

OK, the issue is that this trips the part for signed numeric literals in the scanner, so the parser does not get

 TOK_OPEN_PAREN number TOK_SLASH number TOK_CLOSE_PAREN TOK_PLUS number

but

 TOK_OPEN_PAREN number TOK_SLASH number TOK_CLOSE_PAREN signed-number

and therefore bails out with the unexpected literal at the end.

The workaround (also for old versions) is to add a space character after the + :

-COMPUTE Num4 = (3/2)+3
+COMPUTE Num4 = (3/2)+ 3

Note: this also applies to simpler computations:

COMPUTE Num4 = 2+3 --> syntax error
COMPUTE Num4 = 2+ 3 --> fine

[Simon Sobisch]

Rechecked: according to the standard that's fine:

• an integer may only contain one sign which must be the very first character
• arithmetic operators "are represented by specific COBOL characters that shall be preceded by a space and followed by a space except that no space is required between a left parenthesis and a unary operator or between a unary operator and a left parenthesis."

Rechecked with MF: this recognizes the literal as verb; both this specific one and the 2+3 variant :)

    18     compute num-4 = (3/2)+3
**    COBCH0301S Unrecognized verb  : compute1.cbl(18,34,33)
    18     compute num-4 = 2+3
**    COBCH0301S Unrecognized verb  : compute1.cbl(18,30,29)

[Simon Sobisch]

Where do we stand with that?

• MF errors on that with "recognizing" it as an unknown verb
• GnuCOBOL says "error: syntax error, unexpected Literal"
• gcobol says

<source>:18:33: error: syntax error, unexpected numeric literal
   18 |            compute num-4 = (3/2)+3
      |                                 ^~ 
cobol1: error: failed compiling <source>

... and my guess is that IBM will error similar.

So - just close this as "not a bug"?

[Mickey White]

On IBM the first program errors out the same.
The second program compiles with warnings , but does not display the decimal point in the answer.
If change 9v9 to 9.9 decimal is displayed.

[Simon Sobisch]

OK, then all compiler agree with the standard here (apart from MF reasoning that as a statement) and we can close this; note that cobc -std=ibm will likely display identical as IBM (as that dialect disables "pretty printing).