| 1. |
|
|
| 2. |
- Jansson, Patrik, 1972, et al.
(författare)
-
Functional Pearl: Polytypic Unification
- 1998
-
Ingår i: Journal of Functional Programming. - 1469-7653 .- 0956-7968. ; 8:5, s. 527-536
-
Tidskriftsartikel (refereegranskat)abstract
- Unification, or two-way pattern matching, is the process of solving an equation involving two first-order terms with variables. Unification is used in type inference in many programming languages and in the execution of logic programs. This means that unification algorithms have to be written over and over again for different term types. Many other functions also make sense for a large class of datatypes; examples are pretty printers, equality checks, maps etc. They can be defined by induction on the structure of user-defined datatypes. Implementations of these functions for different datatypes are closely related to the structure of the datatypes. We call such functions polytypic. This paper describes a unification algorithm parametrised on the type of the terms, and shows how to use polytypism to obtain a unification algorithm that works for all regular term types.
|
|
| 3. |
- Jansson, Patrik, 1972, et al.
(författare)
-
PolyLib - a polytypic function library
- 1998
-
Ingår i: Workshop on Generic Programming.
-
Konferensbidrag (refereegranskat)abstract
- A polytypic program is a program that behaves uniformly over a large class of datatypes. For functional polytypic programming this uniformity is achieved by parameterizing functions over type constructors to obtain polytypic functions. A polytypic function is defined either by induction on the structure of regular type constructors or in terms of other polytypic functions. PolyP is an extension of the functional programming language Haskell with a construct for defining polytypic functions. PolyP is a type guided preprocessor that generates instances of polytypic functions and inserts applications of these instances where needed.During the last few years we have used PolyP to construct a number of polytypic programs, for example for unification, parsing, rewriting, pattern matching, etc. These polytypic programs use several basic polytypic functions, such as the relatively well-known cata and map, but also less well-known functions such as propagate and thread. We have collected these basic polytypic functions in the library of PolyP: PolyLib. This paper describes the polytypic functions in PolyLib, motivates their presence in the library, and gives a rationale for their design. Thus we hope to share our experience with other researchers in the field. We will assume the reader has some familiarity with the field of polytypic programming.Of course, a library is an important part of a programming language. Languages like Java, Delphi, Perl and Haskell are popular partly because of their useful and extensive libraries. For a polytypic programming language it is even more important to have a clear and well-designed library: writing polytypic programs is difficult, and we do not expect many programmers to write polytypic programs. On the other hand, many programmers use polytypic programs such as parser generators, equality functions, etc.This is a first attempt to describe the library of PolyP; we expect that both the form and content of this description will change over time. One of the goals of this paper is to obtain feedback on the library design from other researchers working within the field. At the moment the library only contains the basic polytypic functions. In the future we will develop special purpose sublibraries for polytypic functions with more advanced functionality, for example for parsing and the other programs mentioned above.
|
|
| 4. |
- Svensson, Johan, 1964, et al.
(författare)
-
Treatment with the oral growth hormone secretagogue MK-677 increases markers of bone formation and bone resorption in obese young males.
- 1998
-
Ingår i: Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research. - 0884-0431. ; 13:7, s. 1158-66
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of 2 months of treatment with the oral growth hormone (GH) secretagogue MK-677 on markers of bone metabolism was determined in healthy obese male subjects. This was a randomized, double-blind, parallel, placebo-controlled study. Twenty-four healthy obese males, 19-49 years of age, with body mass index > 30 kg/m2 were treated with MK-677 (25 mg/day; n = 12) or placebo (n = 12) for 8 weeks. MK-677 increased markers of bone formation; a 23% increase in the carboxy-terminal propeptide of type I procollagen levels and a 28% increase in procollagen III peptide levels were seen with as little as 2 weeks of MK-677 treatment (p < 0.01 and p = 0.001 vs. placebo, respectively) while a 15% increase in serum levels of osteocalcin was not detected until 8 weeks of treatment (p < 0.01 vs. placebo). Markers of bone resorption were induced within 2 weeks of treatment with MK-677; serum levels of the carboxy-terminal cross-linked telopeptide of type I collagen were increased 26% at 8 weeks (p = 0.001 vs. placebo), and urine hydroxyproline/creatinine and calcium/creatinine ratios at 8 weeks were increased by 23% (p < 0.05 vs. placebo) and 46% (p < 0.05 vs placebo), respectively, MK-677 increased serum insulin-like growth factor binding protein-5 (IGFBP-5) by 43-44% after 2-8 weeks of treatment (p < 0.01 vs. placebo). Serum IGFBP-4 was increased by 25% after 2 weeks of treatment (p < 0.001 vs. placebo) but no significant change from baseline was observed after 8 weeks of treatment. Plasma interleukin-6 was not significantly changed by active treatment. In conclusion, short-term treatment of healthy obese male volunteers with the GH secretagogue MK-677 increases markers of both bone resorption and formation. Large increases in serum levels of IGF-1 and IGFBP-5 and a transient increase in serum IGFBP-4 were found. Future long-term studies are needed to investigate if prolonged treatment with MK-677 increases bone mass.
|
|
