Space (punctuation)In writing, a space () is a blank area that separates words, sentences, syllables (in syllabification) and other written or printed glyphs (characters). Conventions for spacing vary among languages, and in some languages the spacing rules are complex. Inter-word spaces ease the reader's task of identifying words, and avoid outright ambiguities such as "now here" vs. "nowhere". They also provide convenient guides for where a human or program may start new lines.
Command-line interfaceA command-line interface (CLI) is a means of interacting with a device or computer program with commands from a user or client, and responses from the device or program, in the form of lines of text. Such access was first provided by computer terminals starting in the mid-1960s. This provided an interactive environment not available with punched cards or other input methods. Operating system command-line interfaces are often implemented with command-line interpreters or command-line processors.
Tab keyThe tab key (abbreviation of tabulator key or tabular key) on a keyboard is used to advance the cursor to the next tab stop. The word tab derives from the word tabulate, which means "to arrange data in a tabular, or table, form." When a person wanted to type a table (of numbers or text) on a typewriter, there was a lot of time-consuming and repetitive use of the space bar and backspace key. To simplify this, a horizontal bar was placed in the mechanism called the tabulator rack.
Free-form languageIn computer programming, a free-form language is a programming language in which the positioning of characters on the page in program text is insignificant. Program text does not need to be placed in specific columns as on old punched card systems, and frequently ends of lines are insignificant. Whitespace characters are used only to delimit tokens, and have no other significance. Most free-form languages descend from ALGOL, including C, Pascal, and Perl. Lisp languages are free-form, although they do not descend from ALGOL.
Indentation (typesetting)FORCETOC In the written form of many languages, an indentation or indent is an empty space at the beginning of a line to signal the start of a new paragraph. Many computer languages have adopted this technique to designate "paragraphs" or other logical blocks in the program. For example, the following lines are indented, using between one and six spaces: This paragraph is indented by 1 space. This paragraph is indented by 3 spaces. This paragraph is indented by 6 spaces.
Off-side ruleA computer programming language is said to adhere to the off-side rule of syntax if blocks in that language are expressed by their indentation. The term was coined by Peter Landin, possibly as a pun on the offside rule in association football. This is contrasted with free-form languages, notably curly-bracket programming languages, where indentation has no computational meaning and indent style is only a matter of coding conventions and formatting. Off-side-rule languages are also described as having significant indentation.
NewlineA newline (frequently called line ending, end of line (EOL), next line (NEL) or line break) is a control character or sequence of control characters in character encoding specifications such as ASCII, EBCDIC, Unicode, etc. This character, or a sequence of characters, is used to signify the end of a and the start of a new one. In the mid-1800s, long before the advent of teleprinters and teletype machines, Morse code operators or telegraphists invented and used Morse code prosigns to encode white space text formatting in formal written text messages.
Control characterIn computing and telecommunication, a control character or non-printing character (NPC) is a code point in a character set that does not represent a written character or symbol. They are used as in-band signaling to cause effects other than the addition of a symbol to the text. All other characters are mainly graphic characters, also known as printing characters (or printable characters), except perhaps for "space" characters. In the ASCII standard there are 33 control characters, such as code 7, , which rings a terminal bell.
Indentation styleIn computer programming, an indentation style is a convention governing the indentation of blocks of code to convey program structure. This article largely addresses the free-form languages, such as C and its descendants, but can be (and often is) applied to most other programming languages (especially those in the curly bracket family), where whitespace is otherwise insignificant. Indentation style is only one aspect of programming style. Indentation is not a requirement of most programming languages, where it is used as secondary notation.
UTF-8UTF-8 is a variable-length character encoding standard used for electronic communication. Defined by the Unicode Standard, the name is derived from Unicode (or Universal Coded Character Set) Transformation Format - 8-bit. UTF-8 is capable of encoding all 1,112,064 valid character code points in Unicode using one to four one-byte (8-bit) code units. Code points with lower numerical values, which tend to occur more frequently, are encoded using fewer bytes.
