parsing text with Parse::RecDescent - perl

Question

I am trying to parse some text with Parse::RecDescent
from :
x=2 and y=2 and f=3 and (x has 3,4 or r=5 or r=6 ) and z=2
to something like :
x equal 2 and y equal 2 and f equal 3 and (( x contains 3 or x contains 4 or r equal 5 or requal 6 )) and z equal 2
other example :
input :
x= 3 and y has 5 and (z has 6 or z=3 ) and f=2
output :
x equals 3 and (( y contains 5)) and ((z has 6 or z equals 3)) and f equals 2
my question if i find a list of those operators :
has ,or
i should put "((" before the code and "))" after the code as mentioned on the example aboves
is it possible to do something like this with Parse::RecDescent ?

Answer 1

The grammar would look something like the following:
parse : expr EOF
expr : logic_or
# vvv Lowest precedence vvv
logic_or : <leftop: logic_and LOGIC_OR logic_and>
logic_and : <leftop: comparison LOGIC_AND comparison>
comparison : term comparison_[ $item[1] ]
comparison_ : '=' term
| HAS ident_list
|
# ^^^ Highest precedence ^^^
ident_list : <leftop: IDENT ',' IDENT>
term : '(' expr ')'
| IDENT
# Tokens
IDENT : /\w+/
LOGIC_OR : /or\b/
LOGIC_AND : /and\b/
HAS : /has\b/
EOF : /\Z/
Now you just need to add the code block to emit the desired output.
In comparison_, the LHS term is available as $arg[0].
I had to make some assumptions, so there could be errors.