KPeg.grammar do |g|
g.sp = g.kleene " "
g.var = g.any("-", /[a-zA-Z][-_a-zA-Z0-9]*/)
g.var_ref = g.seq(:var) { |x| ref(x) }
g.dbl_escapes = g.str('\"') { '"' } \
| g.str('\n') { "\n" } \
| g.str('\t') { "\t" } \
| g.str('\\\\') { "\\" }
g.dbl_not_quote = g.many(g.any(:dbl_escapes, /[^"]/)) { |*a| a.join }
g.dbl_string = g.seq('"', g.t(:dbl_not_quote, "str"), '"') { |x| str(x) }
g.sgl_escape_quote = g.str("\\'") { "'" }
g.sgl_not_quote = g.many(g.any(:sgl_escape_quote, /[^']/)) { |*a| a.join }
g.sgl_string = g.seq("'", g.t(:sgl_not_quote, "str"), "'") { |x| str(x) }
g.string = g.any(:dbl_string, :sgl_string)
g.not_slash = g.many(g.any('\/', %r![^/]!)) { |*a| a.join }
g.regexp = g.seq('/', :not_slash, '/') { |_,x,_| reg(Regexp.new(x)) }
g.char = /[a-zA-Z0-9]/
g.char_range = g.seq('[', g.t(:char, "l"), '-', g.t(:char, "r"), ']') {
|l,r| range(l, r)
}
g.range_elem = /([1-9][0-9]*)|\*/
g.mult_range = g.seq('[', :sp, g.t(:range_elem, "l"), :sp, ',',
:sp, g.t(:range_elem, "r"), :sp, ']') {
|a,b|
[a == "*" ? nil : a.to_i,
b == "*" ? nil : b.to_i]
}
g.curly_block = g.seq(:curly) { |a| Array(a[1]).join }
g.curly = g.seq("{", g.kleene(g.any(/[^{}]+/, :curly)), "}")
g.spaces = g.kleene(" ")
g.value = g.seq(:value, ":", :var) { |a,_,b| t(a,b) } \
| g.seq(:value, "?") { |v,_| maybe(v) } \
| g.seq(:value, "+") { |v,_| many(v) } \
| g.seq(:value, "*") { |v,_| kleene(v) } \
| g.seq(:value, :mult_range) { |v,r| multiple(v, *r) } \
| g.seq("&", :value) { |_,v| andp(v) } \
| g.seq("!", :value) { |_,v| notp(v) } \
| g.seq(:value, :spaces, :value) { |a,_,b| seq(a, b) } \
| g.seq("(", g.t(:outer, "o"), ")") { |o| o } \
| g.seq(:curly_block) { |a| action(a) } \
| g.str(".") { dot } \
| g.char_range | g.regexp | g.string | g.var_ref
g.bsp = g.kleene g.any(" ", "\n")
g.choose_cont = g.seq(:bsp, "|", :bsp, g.t(:value, "v")) { |x| x }
g.outer = g.seq(:value, g.many(:choose_cont)) {
|a,b| b.kind_of?(Array) ? any(a, *b) : any(a, b)
} \
| g.value
g.assignment = g.seq(:sp, g.t(:var, "v"), :sp, "=", :sp, g.t(:outer, "o")) {
|v,e| set(v, e); [:set, v, e]
}
g.assignments = g.seq(:assignment, g.maybe([:sp, "\n", :assignments])) {
|a,b| b.empty? ? a : [:rules, a, b.last]
}
g.root = g.seq(:assignments, :sp, g.maybe("\n")) { |a,_,_| a }
end
