4. Definitions (cont')

Implementation . particular set of software (running in a particular
translation environment under
particular control options) that performs translation of programs for, and
supports execution of methods in, a
particular execution environment.
Namespace . a logical organizational system that provides a way of
presenting program elements that are
exposed to other programs.
Parameter . a variable declared as part of a method, instance constructor,
or indexer definition, which
acquires a value on entry to that method. It is also known as formal
parameter.
Program . refers to one or more source files that are presented to the
compiler. Essentially, a program is
the input to the compiler.
Program, valid . a C# program constructed according to the syntax rules and
diagnosable semantic rules.
Program instantiation . the execution of an application.
Recommended practice — specification that is strongly recommended as being
aligned with the intent of
the standard, but that may be impractical for some implementations
Source file . an ordered sequence of Unicode characters. Source files
typically have a one-to-one
correspondence with files in a file system, but this correspondence is not
required.
Unsafe code . code that is permitted to perform such lower-level operations
as declaring and operating on
pointers, performing conversions between pointers and integral types, and
taking the address of variables.
Such operations provide functionality such as permitting interfacing with
the underlying operating system,
accessing a memory-mapped device, or implementing a time-critical algorithm.
Warning, compile-time . an informational message reported during program
translation, that is intended
to identify a potentially questionable usage of a program element.