|Perl Language Reference Manual|
by Larry Wall and others
Paperback (6"x9"), 724 pages
RRP £29.95 ($39.95)
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- A name you give to a statement so that you can talk about that statement elsewhere in the program.
- The quality that makes you go to great effort to reduce overall energy expenditure. It makes you write labor-saving programs that other people will find useful, and document what you wrote so you don't have to answer so many questions about it. Hence, the first great virtue of a programmer. Also hence, this book. See also impatience and hubris.
- A bit shift that multiplies the number by some power of 2.
- The preference of the regular expression engine to match the leftmost occurrence of a pattern, then given a position at which a match will occur, the preference for the longest match (presuming the use of a greedy quantifier). See 11 for much more on this subject.
- Fancy term for a token.
- Fancy term for a tokener.
- Fancy term for tokenizing.
- Looking at your Oxford English Dictionary through a microscope. (Also known as static scoping, because dictionaries don't change very fast.) Similarly, looking at variables stored in a private dictionary (namespace) for each scope, which are visible only from their point of declaration down to the end of the lexical scope in which they are declared. --Syn. static scoping. --Ant. dynamic scoping.
- A variable subject to lexical scoping, declared by my ( ). Often just called a "lexical". (The our ( ) declaration declares a lexically scoped name for a global variable, which is not itself a lexical variable.)
- Generally, a collection of procedures. In ancient days, referred to a collection of subroutines in a .pl file. In modern times, refers more often to the entire collection of Perl modules on your system.
- Last In, First Out. See also FIFO. A LIFO is usually called a stack.
- In Unix, a sequence of zero or more non-newline characters terminated with a newline character. On non-Unix machines, this is emulated by the C library even if the underlying operating system has different ideas.
- Used by a standard I/O output stream that flushes its buffer after every newline. Many standard I/O libraries automatically set up line buffering on output that is going to the terminal.
The number of lines read previous to this one, plus 1. Perl keeps a
separate line number for each source or input file it opens. The
current source file's line number is represented by
__LINE__. The current input line number (for the file that was most recently read via
<FH>) is represented by the
$INPUT_LINE_NUMBER) variable. Many error messages report both values, if available.
- Used as a noun, a name in a directory, representing a file. A given file can have multiple links to it. It's like having the same phone number listed in the phone directory under different names. As a verb, to resolve a partially compiled file's unresolved symbols into a (nearly) executable image. Linking can generally be static or dynamic, which has nothing to do with static or dynamic scoping.
- A syntactic construct representing a comma-separated list of expressions, evaluated to produce a list value. Each expression in a LIST is evaluated in list context and interpolated into the list value.
- An ordered set of scalar values.
- The situation in which an expression is expected by its surroundings (the code calling it) to return a list of values rather than a single value. Functions that want a LIST of arguments tell those arguments that they should produce a list value. See also context.
- An operator that does something with a list of values, such as join ( ) or grep ( ). Usually used for named built-in operators (such as print ( ), unlink ( ), and system ( )) that do not require parentheses around their argument list.
- An unnamed list of temporary scalar values that may be passed around within a program from any list-generating function to any function or construct that provides a list context.
- A token in a programming language such as a number or string that gives you an actual value instead of merely representing possible values as a variable does.
- From Swift: someone who eats eggs little end first. Also used of computers that store the least significant byte of a word at a lower byte address than the most significant byte. Often considered superior to big-endian machines. See also big-endian.
- Not meaning the same thing everywhere. A global variable in Perl can be localized inside a dynamic scope via the local ( ) operator.
- Symbols representing the concepts "and", "or", "xor", and "not".
- An assertion that peeks at the string to the right of the current match location.
- An assertion that peeks at the string to the left of the current match location.
- A construct that performs something repeatedly, like a roller coaster.
loop control statement
- Any statement within the body of a loop that can make a loop prematurely stop looping or skip an iteration. Generally you shouldn't try this on roller coasters.
- A kind of key or name attached to a loop (or roller coaster) so that loop control statements can talk about which loop they want to control.
- Able to serve as an lvalue.
Term used by language lawyers for a storage location you can assign a
new value to, such as a variable or an element of an
array. The "l" is short for "left", as in the left side of an
assignment, a typical place for lvalues. An lvaluable function or
expression is one to which a value may be assigned, as in
pos($x) = 10.
- An adjectival pseudofunction that warps the meaning of an lvalue in some declarative fashion. Currently there are three lvalue modifiers: my ( ), our ( ), and local ( ).
|ISBN 9781906966027||Perl Language Reference Manual||See the print edition|