Object I/O

... or Why you don't need to invent a new syntax for every object type in muSE.

Standard Scheme (RnRS) has special read/write syntax for vectors which goes like this - #(1 2 3 4), which will print out as #4(1 2 3 4). muSE doesn't have such special syntax for objects because its syntax for read-time evaluation is general enough to cover vectors, hashtables and (as far as I can see) all new object types that can be added to muSE in the future.

The idea is dead simple and is based on the read-time evaluation done by muSE. It is quite likely that you'll have written a function that takes a list of arguments and constructs your object. In the case of vectors, muSE has vector that's used like (vector 1 2 3 4) and in the case of hashtables, it has hashtable that's used like (hashtable '((key1 . value1) (key2 . value2))).

Whenever the writer encounters an object, it simply has to write it out in that "constructor" function notation, using {} instead of (). When such an expression is read back in by muSE, the reader will expand the braces and return the constructed object directly. For example -
> (define v (vector 1 2 3 4))
> (write v)
{vector 1 2 3 4}

When the reader reads the following expression -
(third item {vector 1 2 3 4} is a vector)
you'll actually get a vector as the third item in the above list.