OP_CHECKCOLORVERIFY: soft-fork for native color coin support

[TierNolan]

TierNolan: learn about merkelized abstract syntax trees.

There is no Google hit for "merkelized abstract syntax tree"

However, a syntax tree is basically the root of a tree of instructions.  Do you mean that you give the root node of a tree that defines the operations?

I don't see that as an improvement.  You still need to provide the entire script when spending the coin?

What I was suggesting was a way to add code for functions.

Maybe

<name> OP_CALL

is a better description.  That would call the given function.

[Peter Todd]

"merkelized abstract syntax tree" == "abstract syntax tree + hashing"

You only provide the parts of the tree actually executed, take advantage of that.

Making transactions as statefull as you suggest - depending on external data for the scripts - has many severe drawbacks due to the non-determinism and complexity. Anyway with MASTs that step can be just a matter of optional blockchain compression.

[TierNolan]

Anyway with MASTs that step can be just a matter of optional blockchain compression.

That's true, the "real" script could be the expanded version.  If a client finds a particular sequence of bytes repeating in script, then it could have some way tell its peers about it.