Re: S-expressions with Marpa::R2: Grammar for Numbers

I can't test it but I would start with:


atom ::= string
       | number
       | symbol

number_chars ::= SIGN? DIGITS action => Sexp::Tiny::Actions::do_join
SIGN           ~ "+" | "-"
DIGITS         ~ [0-9]

# Exclude the new starting characters for numbers from the "symbol" character class
SYMCHAR ~ [^()\s"0-9+-]

Replies

Re^2: S-expressions with Marpa::R2: Grammar for Numbers [ choroba ] 2025-12-22 17:25:18

Or, if you want to support the exponential notation, too:

number     ~ sign_maybe digit_many e
           | sign_maybe digit_any '.' digit_many e_maybe
           | sign_maybe digit_many e_maybe
           | sign_maybe non_zero digit_any

empty      ~
sign_maybe ~ [+-] | empty
digit      ~ [0-9]
non_zero   ~ [1-9]
digit_any  ~ digit*
digit_many ~ digit+
e          ~ [Ee] sign_maybe digit_many
e_maybe    ~ e | empty

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]