In this section, we will explore the "system functions" and "system constants", which are essential to understanding the foundational capabilities of VCSSL.

System Functions and Constants

"System functions" are functions provided by the system (interpreter) that processes VCSSL programs, unlike user-defined functions.

You've already used system functions multiple times in the content discussed so far. For example, the "print" function, which is used for outputting results, is a system function. In other words, you've been invoking functionalities of the VCSSL processing system to perform screen outputs.

Alongside these functions, the system also defines certain values, like the "maximum integer value that can be handled," as default constants.

System Functions/Constants Belong to the "System Library"

VCSSL allows for the grouping of multiple functions, variables, and more, into entities known as "libraries."

Some libraries, referred to as standard libraries, come bundled with the VCSSL processing system by default. The system functions/constants are grouped under one of these standard libraries: the "System" library.

Usually, to use a library, you need to specify that it should be loaded (using "import" or "include" declarations). However, since the "System" library is almost always needed, it is automatically loaded by default, requiring no additional action. That's why you've been able to use functions like "print" anytime.

For a detailed list of system functions/constants and their precise explanations, please refer to the following specification document:

Representative System Functions

Function	Parameters (Arguments)	Description
print	Args of any type and in any number	Displays the content of the arguments on the console.
println	Any type and in any number	Displays the content of the arguments on the console and adds a newline.
output	Any type and in any number	Displays the arguments' content in the result display area, or behaves like the println function if such an area is absent.
popup	Any type and in any number	Displays the content of the arguments in a popup window.
input	Any type and in any number	Displays the content of the arguments in an input window and accepts input from the user. The last argument becomes the default input value. The input result is returned as a string type value.
confirm	Any type and in any number	Displays the content of the arguments in an input window and accepts a YES/NO selection from the user. The selection result is returned as a boolean type value.
select	Any type and in any number	Prompts the user to select one item from the arguments. The selection result is returned as a string type value.
choose	Message: string	Prompts the user to choose a file or folder and returns the absolute path of the selected item as a string type value. The message argument specifies the message displayed in the selection dialog. An additional string argument can be passed to specify the location (folder) to choose the file.
sleep	Stop time in milliseconds: int	Pauses program execution for the specified time.
exit	None	Terminates program execution.
hide ※	None	Makes the console invisible.
show	None	Makes the console visible.
clear	None	Clears the content of the console. However, clearing may not be possible depending on the processing system or settings.
save	File path: string	Saves the current content of the console to the specified file. Adding another argument saves the value of that argument instead of the console content.
load	None	Returns the current content of the console as a string value. Adding another argument and specifying a file path reads the content of that file instead of the console and returns it.
re	Complex or varcomplex value	Returns the real part of the argument. The return type is float if the argument is complex value, and varfloat if it's varcomplex.
im	Complex or varcomplex value	Returns the imaginary part of the argument. The return type is float if the argument is complex, and varfloat if it's varcomplex.

Function

Parameters
(Arguments)

Description

Args of any type and in any number

Displays the content of the arguments on the console.

println

Any type and in any number

Displays the content of the arguments on the console and adds a newline.

output

Any type and in any number

Displays the arguments' content in the result display area, or behaves like the println function if such an area is absent.

popup

Any type and in any number

Displays the content of the arguments in a popup window.

input

Any type and in any number

Displays the content of the arguments in an input window and accepts input from the user. The last argument becomes the default input value. The input result is returned as a string type value.

confirm

Any type and in any number

Displays the content of the arguments in an input window and accepts a YES/NO selection from the user. The selection result is returned as a boolean type value.

select

Any type and in any number

Prompts the user to select one item from the arguments. The selection result is returned as a string type value.

choose

Message: string

Prompts the user to choose a file or folder and returns the absolute path of the selected item as a string type value. The message argument specifies the message displayed in the selection dialog. An additional string argument can be passed to specify the location (folder) to choose the file.

sleep

Stop time in milliseconds: int

Pauses program execution for the specified time.

exit

None

Terminates program execution.

hide ※

None

Makes the console invisible.

show

None

Makes the console visible.

clear

None

Clears the content of the console. However, clearing may not be possible depending on the processing system or settings.

save

File path: string

Saves the current content of the console to the specified file. Adding another argument saves the value of that argument instead of the console content.

load

None

Returns the current content of the console as a string value. Adding another argument and specifying a file path reads the content of that file instead of the console and returns it.

Complex or varcomplex value

Returns the real part of the argument. The return type is float if the argument is complex value, and varfloat if it's varcomplex.

Complex or varcomplex value

Returns the imaginary part of the argument. The return type is float if the argument is complex, and varfloat if it's varcomplex.

Note: The 'hide' function prevents the VCSSL console from closing, potentially leaving no manual way to terminate the program, depending on the processing system. Therefore, in GUI-utilizing programs, ensure to design the program to 'exit' itself, such as by invoking the exit function upon the main window's closure (using 'onWindowClose' event handler).

Representative System Constants

Constant	Type	Description
INT_MAX	int	The maximum value of type int.
INT_MIN	int	The minimum value of type int (maximum negative value).
FLOAT_MAX	float	The maximum positive value for type float. Prepending a negative sign yields the maximum negative value.
FLOAT_MIN_ABS_NORMAL	float	The smallest positive, non-zero absolute value representable in float type within the range of normalized numbers. Note that this is not the maximum value in the negative direction.
FLOAT_MIN_ABS_DENORMAL	float	The smallest positive, non-zero absolute value representable in float type, including the range of denormalized numbers. Note that this is not the maximum value in the negative direction.
>EOL	string	Standard newline code for the environment.
LF	string	The newline code LF (0x0A), dependent on the environment.
CR	string	The newline code LF CR (0x0D), dependent on the environment.
I	complex	Imaginary unit for complex type.
VCI	varcomplex	Imaginary unit for varcomplex type.
NULL	特別な型	Represents an invalid or non-existent value. Strings, structures, etc., may hold invalid values, and comparing them with NULL yields true. It is also possible to assign NULL. However, in comparison and assignment with int type, it behaves exceptionally and is equivalent to -1. Note that it is not equivalent to 0.

Constant

Type

Description

INT_MAX

int

The maximum value of type int.

INT_MIN

int

The minimum value of type int (maximum negative value).

FLOAT_MAX

float

The maximum positive value for type float. Prepending a negative sign yields the maximum negative value.

FLOAT_MIN_ABS_NORMAL

float

The smallest positive, non-zero absolute value representable in float type within the range of normalized numbers. Note that this is not the maximum value in the negative direction.

FLOAT_MIN_ABS_DENORMAL

float

The smallest positive, non-zero absolute value representable in float type, including the range of denormalized numbers. Note that this is not the maximum value in the negative direction.

>EOL

string

Standard newline code for the environment.

string

The newline code LF (0x0A), dependent on the environment.

string

The newline code LF CR (0x0D), dependent on the environment.

complex

Imaginary unit for complex type.

VCI

varcomplex

Imaginary unit for varcomplex type.

NULL

特別な型

Represents an invalid or non-existent value. Strings, structures, etc., may hold invalid values, and comparing them with NULL yields true. It is also possible to assign NULL. However, in comparison and assignment with int type, it behaves exceptionally and is equivalent to -1. Note that it is not equivalent to 0.

Various Other Functions/Constants Available

The system functions/constants introduced here are just a subset. Beyond the system functions/constants, the entire standard library offers access to over a thousand diverse functions/constants by default. For more details, please refer to the following standard library specification: