Some small Pact feature suggestions

[jwiegley]

This list is from nuwu on Discord (https://discord.com/channels/502858632178958377/524762252734365696/1072905294604161056):

• Governance delegate: (module app G (defcap G () true)) (module awa app (defun f (x) x)). Doesn't inline, latter module always adopts the governance of former
• Keysets could be scoped by the (namespace) declaration, in order to allow flexible test codes
• Nested object merge: (+ { 'a: { 'b: 2 } } { 'a: { 'c: 3 } }) = { 'a: { 'b: 2, 'c: 3 } }
• Nested binds / deconstruct: (bind ob { 'a := { 'b := b } } ...)
• Unclear how to manage database keys on tree data structure. Should node reference parents (space) or implement a string split function deriving parent from current node key (time)? Seems most implementations store redundant self-referential keys in tables, but it seems wasteful.
• Typed numeric: x:number{token-bun}, which may carry models, precision, allowed values, etc, potentially enforced in the definition of their constructor
• "Subset of" interface: (interface a (defun f:decimal ()) (defun g:decimal ())) (interface b (infer a [ f ])). a "implies" b.
• For some reason, (let ((_:object{schema} o)) 0) behaves oddly
• (pure) function: unlike (try) propagate errors but prohibits database writes. i.e. (pure (modref::fn x))
• Unclear why, but the final default branch of (cond) doesn't allow s-expression, sometimes
• Flexible inference: fix empty lists randomly resulting in type errors