The combination of iterating over an array and removing values from it results
in not all elements being removed. For example:
numbers = [10, 20, 30]
numbers.each do |num|
numbers.delete(num)
end
numbers # => [20]
As a result of this the NodeSet#remove method uses two iterations:
1. One iteration to retrieve all NodeSet instances to remove nodes from.
2. One iteration to actually remove the nodes.
For the second iteration we iterate over the node sets and then over the nodes.
This ensures that we always remove all nodes instead of leaving some behind.
The documentation still leaves a lot to be desired and so does the API. There
also appears to be a problem where NodeSet#remove doesn't properly remove all
nodes from a set. Outside of that we're making slow progress towards a proper
DOM API.
Instead the various nodes can use NodeSet#index (aka Array#index) instead. This
has a slight performance overhead on very large (millions) of nodes but should
be fine in most other cases.
The previous commit didn't fully change the operator precedence according to
the XPath 1.0 specification. Also thanks to @whitequark for clearing up a few
things about Racc's operator precedence system.
Using IO/StringIO objects one can parse large XML files without first having to
read the entire file into memory. This can potentially save a lot of memory at
the cost of a slightly slower runtime.
For IO like instances the lexer will consume the input line by line. If a
String is given it's consumed as a whole instead. A small side effect of
reading the input line by line is that text such as "foo\nbar" will be lexed as
two tokens instead of one.
Fixes#19.
Instead of directly accessing the `data` instance variable the C/Java code now
uses the method `read_data`. This is part of one of the various steps required
to allow Oga to read data from IO like instances. It also means I can freely
change the name of the instance variable without also having to change the
C/Java code.
After discussing this with @headius I've decided to do this the manual way
anyway. Apparently the basic load service stuff is deprecated and not very
reliable.
Yorick Peterse