README.md

Initial play with treetop to try parsing sql.

Cutting parsing tree

Don't know if it a good idea but using

module SQL # custom Node for cutting parsing tree class CutTree < Treetop::Runtime::SyntaxNode def initialize( input, interval, elements = nil) super( input, interval, nil) end end

# 
class KW < CutTree
end

end

allows to cut significantly unusefull part of the tree build by treetop: exemple: rule SELECT 'select'i kw end

[15] pry(main)> m = Parser.parse("select col as a /* truc */ from T")

before SyntaxNode+SELECT0 offset=0, "select " (kw): SyntaxNode offset=0, "select" SyntaxNode+Kw0 offset=6, " " (s): SyntaxNode offset=6, "" SyntaxNode offset=6, " ": SyntaxNode offset=6, " ": SyntaxNode offset=6, " " SyntaxNode offset=7, ""

after KW+SELECT0 offset=0, "select " (kw) SyntaxNode offset=7, ""