Type-Inference Based Short Cut Deforestation (nearly) without Inlining

Deforestation optimises a functional program by transforming it into another one that does not create certain intermediate data structures. In [ICFP'99] we presented a type-inference based deforestation algorithm which performs extensive inlining. However, across module boundaries only limited inlining is practically feasible. Furthermore, inlining is a non-trivial transformation which is therefore best implemented as a separate optimisation pass. To perform short cut deforestation (nearly) without inlining, Gill suggested to split definitions into workers and wrappers and inline only the small wrappers, which transfer the information needed for deforestation. We show that Gill's use of a function build limits deforestation and note that his reasons for using build do not apply to our approach. Hence we develop a more general worker/wrapper scheme without build. We give a type-inference based algorithm which splits definitions into workers and wrappers. Finally, we show that we can deforest more expressions with the worker/wrapper scheme than the algorithm with inlining

Polymorphism, subtyping, and type inference in MLsub

We present a type system combining subtyping and ML-style parametric polymorphism. Unlike previous work, our system support type inference and has compact principal types. We demonstrate this system in the minimal language MLsub, which types a strict superset of core ML programs. This is made possible by keeping a strict separation between the types used to describe inputs and those used to describe outputs, and extending the classical unification algorithm to handle subtyping constraints between these input and output types. Principal types are kept compact by type simplification, which exploits deep connections between subtyping and the algebra of regular languages. An implementation is available online

Automated Execution of Financial Contracts on Blockchains

The paper investigates financial contract management on distributed ledgers and provides a working solution implemented on the Ethereum blockchain. The system is based on a domain-specific language for financial contracts that is capable of expressing complex multi-party derivatives and is conducive to automated execution. The authors propose an architecture for separating contractual terms from contract execution: a contract evaluator encapsulates the syntax and semantics of financial contracts without actively performing contractual actions; such actions are handled by user-definable contract managers that administer strategies for the execution of contracts. Hosting contracts and contract managers on a distributed ledger, side-by-side with digital assets, facilitates automated settlement of commitments without the need for an intermediary. The paper discusses how the proposed technology may change the way financial institutions, regulators, and individuals interact in a financial system based on distributed ledgers

Three-dimensionally confined diluted magnetic semiconductor clusters. Zn1−xMnxS

We report the first example of a dilute magnetic semiconductor (DMS) confined in all three dimensions (DMS quantum dot). Zn0.93Mn0.07S clusters of not, vert, similar 25 Å diameter are successfully synthesized inside a glass matrix and fully characterized by chemical analysis, x-ray diffraction, extended x-ray absorption fine structure (EXAFS), and photoluminescence spectroscopy. Effect of size quantization on the exciton energy has been observed. Preliminary magnetic susceptibility data are presented and discussed