Sha256: 42867c6f91049685580c71950cc2dcc05543141da406c1f75736d2b4a9a4a866
Contents?: true
Size: 1.42 KB
Versions: 5
Compression:
Stored size: 1.42 KB
Contents
module Alf
module Support
class Tree
EMPTY_CHILDREN = [].freeze
def initialize(root)
@root = root
end
attr_reader :root
def label(node)
case node
when Sexpr then node.first.to_s
when Algebra::Operand::Proxy then label(node.subject)
when Relation::DUM then "DUM"
when Relation::DEE then "DEE"
when Relation then "Relation(...)"
when Relvar then "#{node.class} ..."
else node.to_s
end
end
def children(node)
case node
when Sexpr then node.sexpr_body
when Relvar then [node.expr]
when Algebra::Operator then node.operands
when Algebra::Operand then EMPTY_CHILDREN
when Engine::Cog then node.children
else EMPTY_CHILDREN
end
end
def to_text(buffer = '', node = root, depth = 0, open = [])
depth.times do |i|
buffer << ((i==depth-1) ? "+-- " : (open[i] ? "| " : ' '))
end
buffer << label(node) << "\n"
children = children(node)
children.each_with_index do |child, index|
open[depth] = (index != children.size-1)
to_text(buffer, child, depth+1, open)
end
buffer
end
alias :to_s :to_text
end # class Tree
end # module Support
end # module Alf
Version data entries
5 entries across 5 versions & 1 rubygems