On 02/07/2022 01:28, Robert Elz wrote:
| FreeBSD 13.1 | #|f-1301-x86:~$ sh -c '(i=10; echo $((++-+++i)))' | sh: arithmetic expression: expecting primary: "++-+++i" We used to do that as well (our arith parser is derived from theirs, which is derived from dash's with extensions) but no-one ever understood what a "primary" was (relates to internal implementation function names) so I altered the err msg.
While there is a function called primary, I actually think that may not be what the error message refers to, not directly. The grammar is supposed to be the C grammar with unsupported constructs removed, the C grammar defines a "primary-expression", and the error message in dash shows up where a straightforward parser directly based on the C grammar would result in an error where the grammar demands a primary-expression.
The function called primary ended up doing more than parse a primary-expression, but that does not change which cases result in that error.
Cheers, Harald van Dijk
