piraha accepts in-string comments on first line of string

[Roland Haas]

Cactus' parameter files allow things like:

ActiveThorns = "
# PUGH
Carpet
HydroBase
"

ie allow one to comment out lines in a multi-line string by starting it with a “#”. However Piraha does not quite handle this correctly. It accepts

ActiveThorns = "#FooBar"

which is incorrect. # comments are supposed to be only allowed in lines after the first line. The original commit git hash b6cd766a "Accept comments in multi-line strings in parameter files" of cactus does this but piraha’s string_reparser function (bad name) does not.

This makes it impossible to set a string to “#” eg if one wanted to let a user specify a comment character for output files.

[Steven R. Brandt]

https://bitbucket.org/cactuscode/cactus/pull-requests/87/fix-issue-2331/diff

‌

[Roland Haas]

This seems incorrect to me. The C++ code uses "stringfirstname" while the peg file has "stringfirstline".

Note that even when changing them to be consistent, this parameter file:

$bar = "time"
Cactus::terminate = "$bar"

fails with

WARNING[L1,P0] (Cactus): Major error in parameter file 'par/tov.par' line 2: Range error setting parameter 'Cactus::terminate' to '$bar'

ie variables are not expanded on the first line (b/c it is always used literally). See #2333 though for whether or not expanding variables in strings is the right thing to do anyway.

A better peg file (ignoring the C++ code for brevity of presentation) seems to me to be:

stringparser = ^({var}|{name}|{stringfirstline})*(\n({stringcomment}|{var}|{name}|{any})*)?$

I have updated the branch and pull request with this suggestion.

[Steven R. Brandt]

Yes, I realized this after I created it. That’s what you get for working while ill.

[Roland Haas]

I believe the updated pull request https://bitbucket.org/cactuscode/cactus/pull-requests/87/fix-issue-2331/diff now contains a fix. @Steven R. Brandt do you agree (see the discussion in the pull request as well)?

[Roland Haas]

Applied as git hash 56ad67d7 "Cactus: add explicit dep on ParGrammar.hh for Call.cc.d" of cactus