[REBOL] Re: Help function for contracts
From: jan:skibinski:sympatico:ca at: 18-Oct-2002 20:13
Gregg Irwin wrote:
> Also, what do you think about ordering the parameters to CONTRACT in the
> order that they are applied (as it were): spec pre local body post ?
I just posted the updated version of dbc.r
The blocks have been reordered, as you suggested.
I also added a wrapper, which takes a regular existing function and wraps
a contract arount it, as in:
g: wrap-dbc pre :f post
I might extend it a bit to handle native! functions too.
Some fiddling was required because a spec copied from a function f,
such as:
["Comment" x [integer!]]
would get converted by the "make function! spec body" into:
["Comment" x [datatype!]]
Apparently what looked and was printed as 'word was not
a 'word at all! :-)
One question: How to programmatically insert line breaks into
a series of blocks?
The reason for this is that I'd like to maintain a neat layout
of a source code produced by the wrapper. Inside the wrap-dbc
you will see an ugly trick with empty blocks that almost
does what I want.
body: reduce [
[]
'require pre
[]
to-set-word 'result 'do fun-body
[]
'ensure post
[]
'result
]
Best wishes,
Jan
