#include <x/yaml/sequencenode.H> switch (n->nodetype) { // ... case YAML_SEQUENCE_NODE: handle_sequence(x::yaml::sequencenode(n)); break; // ... }; // ... void handle_sequence(const x::yaml::sequencenode &seq) { size_t n=seq->size(); std::cout << n << " elements" << std::endl; for (size_t i=0; i<n; ++i) dump(x::yaml::scalarnode(seq->get(i))); }
x::yaml::sequencenode
refers to a
subclass of
x::yaml::nodeObj that
represents a sequence in a YAML document. Its
size() method gives the number of values
in the sequence.
get() returns a
x::yaml::node, which can be converted to
another
x::yaml::scalarnode,
x::yaml::sequencenode, or an
x::yaml::mappingnode,
according to its nodetype.
void handle_sequence(const x::yaml::sequencenode &seq) { for (x::yaml::scalarnode scalar: *seq) { dump(scalar); } }
The referenced sequence object implements a
begin() and an
end() that return
x::yaml::sequencenode::base::iterators over
x::yaml::node values in the sequence.
This example iterates over a sequence that's expected to consist
entirely of
x::yaml::scalarnode
values, so the range iteration value gets coerced accordingly.
An exception gets thrown in the event
of a type conversion failure if the sequence contains a different node
type.
void handle_sequence(const x::yaml::sequencenode &seq) { seq->for_each([], (x::yaml::scalarnode &&n) { dump(n); }); }
The for_each() method produces slightly
more efficient code that iterates over the sequence, and invokes the
functor or the lambda argument passing each node in the sequence by
rvalue.
Sequences do not have to be mono-typed. The same sequence may contain
a mixture of
x::yaml::scalarnodes
and
x::yaml::sequencenodes,
for example. In this case, the range iteration or the
for_each() should take a
x::yaml::node rvalue,
then proceed based on its
nodetype.