Comprehension Syntax

. The syntax of comprehensions is very close to the syntax of a number of practical database query languages and is, we believe, a better starting point than first-order logic for the development of database languages. We give an informal account of a language based on comprehension syntax that deals uniformly with a variety of collection types; it also includes pattern matching, variant types and function definition. We show, again informally, how comprehension syntax is a natural fragment of structural recursion, a much more powerful programming paradigm for collection types. We also show that a very small "abstract syntax language" can serve as a basis for the implementation and optimization of comprehension syntax. 1 Introduction Ever since relational databases were first conceived [12], first-order logic, i.e., relational calculus/algebra has been taken as the starting point for the design of relational query languages. It has been an invaluable tool for formulating both semantic..