Simple boolean expression parser Roles using pest.rs https://pest.rs

roles.pest

AND = { "." } 
NOT = { "`" }
OR = { "+" }
SEP = _{ (NEWLINE | WHITE_SPACE) }
VAR_NAME = { (ASCII_ALPHA ~ ASCII_DIGIT*) }

VAR = { VAR_NAME ~ SEP* ~ NOT? ~ SEP* }
EXP = { VAR ~ SEP* ~ ((OR | AND) ~ SEP* ~ VAR ~ SEP*)* }
FUNC = { VAR ~ SEP* ~ "=" ~ SEP* ~ EXP+ }
ROOT = _{ SOI ~ NEWLINE* ~ (FUNC | ANY) ~ NEWLINE* ~ EOI }