Features for early production readiness

[axic]

The items I mentioned being important for "early production readiness":

• ABI encoding/decoding for ADTs
• Storage encoding for ADTs
• ABI encoding for arrays (Support ABI decoding of dynamic arrays of ADTs (calldata, lazy) #526)
• Storage arrays
• Memory arrays
• abi_encode/abi_decode function usable within the language, this is frequently used by building data for signature checking (this likely already exists in some form) (see EIP-712, and Solidity's features)
• support for logs / emit (most of the scaffolding exists, see Supporting logs and events properly #447)
• encoding errors properly (similar work to logs)
• interaction with other contracts, i.e. an "interface" (trait/etc.) and calls to those functions
• public/private functions in contracts (Add public visibility modifier for contract functions #434)
• Signed integer types
• Checked arithmetic by default (Checked arithmetics #484)
• struct data type in memory/ABI (Add Solidity-style structs with named fields and dot access #568)
• struct in storage (Support struct sub-field writes to storage fields #571)

Nice to haves:

• Proper calldata support (i.e. calldata(bytes))
• Fixed-size storage arrays
• Constants
• break in for loops (Implement break in for-loops #488)
• continue in for loops (Support continue in for-loops #490)
• Cleaner literal assignments (i.e. no need for uint256(1234) everywhere)
• Easier type conversions
• Automatic deriving of some traits (Generic deriving implementation #505)
• Syntactical sugar for mod, bitwise and/or/xor (Add bitwise and modulo syntactic sugar #485)
• Syntactical sugar for bitwise not (Add word bitwise NOT with ~ and ~= sugar #536)
• Compound assignments *= and /= (Add *= and /= compound assignment sugar (and extended tests) #537)
• Syntactic sugar for shifts (<<, >>) -- consider arithmetic vs logical
• Syntactical sugar for exp (n ** y)
• Syntactical sugar for ++/-- expressions
• Syntactical sugar for slicing [n:], [n:m], [:m]

I think after these it would be possible to accomplish most needs as a user.