I'm dropping all mention of 'recipe' terminology from the Readme. That
way I hope to avoid further bike-shedding discussions while I very
slowly decide on the right terminology with my students.
I could be smarter in my error messages and use 'recipe' when code uses
it and 'function' otherwise. But what about other words like ingredient?
It would all add complexity that I'm not yet sure is worthwhile. But I
do want separate experiences for veteran programmers reading about Mu on
github and for people learning programming using Mu.
All primitives now always write to all their products. If a product is
not used that's fine, but if an instruction seems to expect too many
products mu will complain.
In the process, many primitives can operate on more than two ingredients
where it seems intuitive. You can add or divide more than two numbers
together, copy or negate multiple corresponding locations, etc.
There's one remaining bit of ugliness. Some instructions like
get/get-address, index/index-address, wait-for-location, these can
unnecessarily load values from memory when they don't need to.
Useful vim commands:
%s/ingredients\[\([^\]]*\)\]/ingredients.at(\1)/gc
%s/products\[\([^\]]*\)\]/products.at(\1)/gc
.,$s/\[\(.\)]/.at(\1)/gc
Swap printing generalized objects using arc's infrastructure to be the
$-prefixed debug helper, while the erstwhile $print-key-to-host becomes
the primitive print-character to host.
This will let me swap in a fake in tests.
Still hacky, though. I'm sure I'm not managing the parameter right in
the chessboard app.
And then there's the question of whether it should also appear as an
output operand.
But it's a start. And using nil to mean 'real' is a reasonable
convention.
If I ever need to handle multiple screens perhaps we'll have to switch
to 1:literal/terminal and 2:literal/terminal, etc. But those are equally
easy to guard on.
'default-scope' is now 'default-space'
'closure-generator' is now 'next-space-generator'
The connection to high-level syntax for closures is now tenuous, so
we'll call the 'outer scope' the 'next space'.
So, let's try to create a few sentences with all these related ideas:
Names map to addresses offset from a default-space when it's provided.
Spaces can be strung together. The zeroth variable points to the next
space, the one that is accessed when a variable has /space:1.
To map a name to an address in the next space, you need to know what
function generated that space. A corollary is that the space passed in
to a function should always be generated by a single function.
Spaces can be used to construct lexical scopes and objects.
This pollutes our traces with all 'system software'. Too much trouble to
keep it out; just lump it for now. Who knows, might even be useful. Most
of the time convert* labels are easy to grep out when debugging.
Will the 'lightweight tools' really be all that useable if we encourage
people to layer them one atop another and track precisely what inputs
each can accept? Something to keep an eye on.
In the meanwhile, we have a new (but very unrealistic) example
demonstrating the tangling directives.
There's still a big constraint on ordering: before/after clauses have to
come before functions that need them.
Kartik K. Agaram