The different namespaces are:
Function Value expression functions, which receive a "context"
Option Command-line options
Precommand Commands which are invoked before reading the journal
Command Commands which are invoked after reading the journal
Directive Directives that occur at column 0 in a data file
This greatly eases the ability for Python uses to add intercept hooks to
change how the basic Ledger module functions. An example of what should
be possible soon:
import ledger
def my_foo_handler(value):
print "--foo received:", value
ledger.add_handler(ledger.Option, "foo=", my_foo_handler)
