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TDT4165: Programming Languages

# Definitions ## Syntax How legal programs are defined ## Semantics Defines what programs do when executed. ## Syntactic sugar Adds a shorthand in the syntax, but does not create a new semantic. ## Linguistic abstraction Abstraction and addition to a language, by using already existing concepts of the language

_Example:_ use `proc` to define `fun` ## Declarative programs - stateless - independt - deterministic In other words, every time you run a declarative program with the same input (or just a declarative component) it will give you the same result (i.e. output). ## Observal declarativity A component can be seen as declarative if the definition is, even though the implementation is not _Example:_ A database with a declarative interface. ## Higher-order programming Use procedure values in programs. (E.g. pass procedures as arguments to other procedures) __Closure__ = procedure value. Four basic operations underlie all techniques in higher order programming ### Procedural abstraction Any statement can be put into a procedure. ### Genericity The ability to pass procedure values as arguments to a procedure call. ### Instatiation The ability to return procedure values as results from a procedure call. ### Embedding Put procedure values in data structures