Glossary
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This glossary defines some general programming terms, as well as terms that are specific to Pascal.
- |
- The bitwise or operator.
- ~
- The bitwise not operator.
- !
- The bitwise or operator.
- #
- A programming symbol that specifies an integer value in a base other than 10, includes a file in your program, or indicates a preprocessor command.
- %
- A programming symbol used with the -xl option for special cppas directives.
- &
- The bitwise and operator.
- adb
- An interactive, general-purpose, assembly-level debugger.
- addr
- A built-in function that returns the address of a specified variable.
- alfa
- An array of char 10 characters long.
- and then
- An operator similar to the standard and operator. The difference is that
and then enforces left-to-right evaluation and evaluates the right operand only if the left operand is true.
- append
- A built-in procedure that opens a file for writing at its end.
- argc
- A built-in function that returns the number of arguments passed to the program.
- argv
- A built-in procedure that assigns the specified program argument to a string variable.
- arshft
- A built-in function that does an arithmetic right shift of an integer value.
- asl
- A built-in function that does an arithmetic left shift of an integer value.
- asr
- A built-in function that does an arithmetic right shift of an integer value. Same as arshft.
- assert
- A statement which causes a boolean expression to be evaluated and aborts the program if false, provided that the -C option is specified.
- bell
- A predeclared character constant equal to char(7), which makes the terminal beep.
- block buffering
- Output buffering with a block size of 1,024.
- card
- A built-in function that returns the number of elements of a set variable.
- clock
- A built-in function that returns the user time consumed by the process.
- close
- A built-in procedure that closes a file.
- compiler directive
- A percent sign (%) followed by a name indicating an action for the cppas preprocessor to take. Programs that contain compiler directives must be compiled with the -xl option.
- concat
- A built-in function that concatenates two strings.
- conditional variable
- A variable, either defined or undefined, handled by the cppas preprocessor. A conditional variable is defined when it appears in a %var directive. Programs that contain conditional variables must be compiled with the -xl option.
- %config
- A compiler directive that is a special predefined conditional variable with a value of either true or false. Programs that contain the %config directive must be compiled with the -xl option.
- cppas
- The preprocessor that handles the Pascal conditional variables and compiler directives when the -xl option is specified.
- date
- A built-in procedure that fetches the current date (as assigned when the operating system was initialized) and assigns it to a string variable.
- dbx
- A symbolic debugger that understands Pascal, Modula-2, C, and FORTRAN programs.
- %debug
- A compiler directive that works with the -cond compiler option.
-cond instructs pc, the Pascal compiler, to compile the lines in your program that begin with %debug. Programs that contain the %debug directive must be compiled with the -xl option.
- define attribute
- An attribute used to declare a variable that is allocated in the current module and whose scope is public.
- define declaration
- A declaration used to declare a variable that is allocated in the current module and whose scope is public.
- discard
- A built-in procedure that throws away the value a function returns.
- double
- A real data type that represents a 64-bit floating-point number. Same as longreal.
- %else
- A compiler directive that provides an alternative action to the %if directive. If the expression in %if is false, the compiler skips over the %then part and executes the %else part instead. Programs that contain the %else directive must be compiled with the -xl option.
- %elseif
- A compiler directive that provides another alternative action to the %if directive. If the expression in %if is false, the compiler skips over the %then part and executes the %elseif part instead. Programs that contain the %elseif directive must be compiled with the -xl option.
- %elseifdef
- A compiler directive that provides an alternative action to the %ifdef directive. If the expression in %ifdef is false, the compiler skips over the %then part and executes the %elseifdef part instead. Programs that contain the %elseifdef directive must be compiled with the -xl option.
- %enable
- A compiler directive that sets a conditional variable to true. Programs that contain the %enable directive must be compiled with the -xl option.
- %endif
- A compiler directive that indicates the end of the %if or %ifdef directive. Programs that contain the %endif directive must be compiled with the -xl option.
- %error
- A compiler directive that prints a string on the standard output and treats it as an error. Programs that contain the %error directive must be compiled with the -xl option.
- errout
- A special predefined file variable equivalent to the operating system standard error file, stderr.
- exit
- A statement used in a for, while, or repeat loop to transfer program control to the first statement after the loop.
- %exit
- A compiler directive that causes the compiler to stop processing the current Pascal source file. Programs that contain the %exit directive must be compiled with the -xl option.
- expo
- A built-in function that calculates the integer-valued exponent of a specified number.
- extern attribute
- An attribute used to declare a variable that is not allocated in the current program or module unit, but is a reference to a variable allocated in another unit.
- extern option
- A procedure and function option that indicates the procedure or function is defined in a separate program or module unit, and possibly in a different source language. Same as external.
- external
- A procedure and function option that indicates the procedure or function is defined in a separate program or module unit, and possibly in a different source language. Same as extern.
- filesize
- A built-in function that returns the current size of a file.
- firstof
- A built-in function that returns the first possible value of a type or variable.
- flush
- A built-in procedure that writes the output buffered for the specified Pascal file into the associated operating system file.
- getenv
- A built-in function that returns the value associated with an environment name.
- getfile
- A built-in function that returns a pointer to the C standard I/O descriptor associated with a Pascal file.
- halt
- A built-in procedure that terminates program execution.
- %if
- A compiler directive. When the compiler encounters a %if expression %then directive, it evaluates expression. If expression is true, the compiler executes the statements after %then. If expression is false, the compiler skips over %then. Programs that contain the %if directive must be compiled with the -xl option.
- %ifdef
- A compiler directive that determines whether or not a conditional variable in a %var directive has been previously defined. Programs that contain the %ifdef directive must be compiled with the -xl option.
- I/O handler
- A Pascal function that is passed the values err_code and filep when an I/O error occurs. The handler returns false to terminate the program, or true to continue program execution.
- in
- A parameter type indicating the parameter can only pass a value into a procedure or function.
- in out
- A parameter type indicating the parameter can both take in values and pass them back out.
- in_range
- A built-in function that checks if a value is in a defined subrange.
- %include
- A compiler directive that instructs cppas to insert the lines from the specified file in the input stream. Programs that contain the %include directive must be compiled with the -xl option.
- include file
- A file that is inserted into a source file with the %include or #include directive.
- index
- A built-in function that returns the position of the first occurrence of a string or character in another string.
- input
- A special predefined file variable equivalent to the standard input file, stdin.
- integer16
- An integer data type that represents a 16-bit value.
- integer32
- An integer data type that represents a 32-bit value.
- internal
- A procedure and function option that makes the procedure or function local to a module.
- intset
- A predefined set of [0..127].
- land
- A built-in function that returns the bitwise and of two integers.
- lastof
- A built-in function that returns the last possible value of a type or variable.
- length
- A built-in function that returns the length of a string.
- line buffering
- The buffering of output line-by-line.
- linelimit
- A built-in procedure that terminates execution of a program after a specified number of lines have been written into a text file.
- %list
- A compiler directive that enables a listing of the program. Programs that contain the %list directive must be compiled with the -xl option.
- lnot
- A built-in function that returns the bitwise not of an integer value.
- longreal
- A real data type that represents a 64-bit floating-point number. Same as double.
- lor
- A built-in function that returns the inclusive or of two integer values.
- lshft
- A built-in function that does a logical left shift of an integer value.
- lsl
- A built-in function that does a logical left shift of an integer value. Same as lshft.
- lsr
- A built-in function that does a logical right shift of an integer value. Same as rshft.
- max
- A built-in function that evaluates two scalar expression and returns the larger one.
- maxchar
- A predeclared character constant equal to char(255).
- maxint
- An integer constant that represents the 16-bit value 32,767 when you compile your program with the -xl option; otherwise, maxint represents the 32-bit value 2,147,483,647.
- message
- A built-in procedure that writes the specified information on stderr, usually the terminal.
- min
- A built-in function that evaluates two scalar expressions and returns the smaller one.
- minchar
- A predeclared character constant equal to char(0).
- minint
- An integer constant that represents the 16-bit value -32,768 when you compile your program with the -xl option; otherwise, minint represents the 32-bit value, -2,147,483,648.
- module heading
- A heading that contains the reserved word module followed by an identifier. For example, module sum; is a legal module heading.
- module unit
- A source program that does not have a program header.
- next
- A statement used in a for, while, or repeat loop to skip to the next iteration of the current loop.
- %nolist
- A compiler directive that disables the program listing. Programs that contain the %nolist directive must be compiled with the -xl option.
- nonpascal
- A procedure and function option that declares non-Pascal routines when you are porting Apollo DOMAIN programs written in DOMAIN Pascal, FORTRAN, C, and C++.
- null
- A built-in procedure that performs no operation.
- open
- A built-in procedure that associates an external file with a file variable.
- or else
- An operator similar to the standard or operator. The difference is that
or else enforces left-to-right evaluation and evaluates the right operand only if the left operand is false.
- otherwise
- A Pascal extension to the standard Pascal case statement. If the value of the case selector is not in the case label list, Pascal executes the statements in the otherwise clause.
- out
- A parameter indicating that the parameter is used to pass values out of the routine.
- output
- A special predefined file variable equivalent to the standard output file, stdout.
- private
- A variable, procedure, or function declaration that restricts its accessibility to the current compilation unit.
- procedure and
function pointer
- A pointer that has the address of a procedure or function as its value.
- public
- A variable, procedure, or function declaration that is visible across multiple programs and modules.
- random
- A built-in function that generates a random number between 0.0 and 1.0.
- remove
- A built-in procedure that removes the specified file.
- return
- A statement used in a procedure or function to prematurely end the procedure or function.
- rshft
- A built-in function that does a logical right shift of an integer value.
- seed
- A built-in function that reseeds the random number generator.
- seek
- A built-in procedure that resets the current position of a file.
- shortreal
- A real data type that represents a 32-bit floating point number. Same as single.
- single
- A real data type that represents a 32-bit floating point number. Same as shortreal.
- sizeof
- A built-in function that returns the number of bytes the program uses to store a data object.
- %slibrary
- A compiler directive that directs cppas to insert the lines from the specified file in the input stream. Same as %include. Programs that contain the %slibrary directive must be compiled with the -xl option.
- stradd
- A built-in procedure that adds a string to the end of another string.
- static
- A variable attribute that declares the variable private in scope.
- stderr
- The standard operating system error file.
- stdin
- The standard operating system input file.
- stdout
- The standard operating system output file.
- stlimit
- A built-in procedure that terminates program execution if a specified number of statements have been executed in the current loop.
- string
- An array of char 80 characters long.
- substr
- A built-in function that extracts a substring from a string.
- sysclock
- A built-in function that returns the system time consumed by the process.
- tab
- A predeclared character constant equal to char(9), which makes a tab character.
- tell
- A built-in function that returns the current position of a file.
- time
- A built-in procedure that retrieves the current time.
- trace
- A built-in procedure that prints stack traceback.
- trim
- A built-in function that removes trailing blanks in a character string.
- type transfer function
- A built-in function that changes the data type of a variable, constant, or expression.
- unit
- Either a program or a module.
- univ
- A modifier used before data types in formal parameter lists to turn off type checking for that parameter.
- univ_ptr
- See universal pointer.
- universal pointer
- A pointer used to compare a pointer of one type to another or to assign a pointer of one type to another.
- %var
- A compiler directive that defines conditional variables for the preprocessor. Programs that contain the %var directive must be compiled with the -xl option.
- variable attribute
- An attribute that determines how to allocate the variable. Variable attributes include static, extern, and define.
- variable initialization
- The initialization of a real, integer, boolean, character, set, record, array, or pointer variable in the var declaration of the program.
- variable routine option
- A routine option that is used to pass a routine a smaller number of actual arguments than the number of formal arguments defined in the routine.
- variable scope
- Either private or public. Visibility of a private variable is restricted to the current compilation unit. A public variable can be referenced across multiple programs and modules.
- variable-length string
- A string of variable length. A variable-length string can be assigned a string of any length, up to the maximum length specified in the declaration. Pascal ignores any characters specified over the maximum.
- varying
- A string of variable length.
- wallclock
- A built-in function that returns the elapsed number of seconds since
00.00.00 GMT January 1, 1970.
- %warning
- A compiler directive that tells the compiler to print a string on the standard output as a warning. Programs that contain the %warning directive must be compiled with the -xl option.
- -xl option
- An option of the pc command that causes the compiler to implement Pascal as DOMAIN Pascal.
- xor
- A built-in function that returns the exclusive or of two integers.