Internal functions/Boolean functions

Revision as of 22:33, 9 May 2013

Boolean functions

These functions return true or false, if the condition that they test holds or not, respectively.

• IsBool   |     |   IsBool(var)

Tests if var is of the bool type. var can be any expression allowed by the AviSynth Syntax.

Examples:

b = false
IsBool(b) = true
IsBool(1 < 2 && 0 == 1) = true
IsBool(123) = false

• IsClip   |     |   IsClip(var)

Tests if var is of the clip type. var can be any expression allowed by the AviSynth Syntax.

Examples:

c = AviSource(...)
IsClip(c) = true
IsClip("c") = false

• IsFloat   |     |   IsFloat(var)

Tests if var is of the float type. var can be any expression allowed by the AviSynth Syntax.

Examples:

f = Sqrt(2)
IsFloat(f) = true
IsFloat(2) = true   # ints are considered to be floats by this function
IsFloat(true) = false

• IsInt   |     |   IsInt(var)

Tests if var is of the int type. var can be any expression allowed by the AviSynth Syntax.

Examples:

IsInt(2) = true
IsInt(2.1) = false
IsInt(true) = false

• IsString   |     |   IsString(var)

Tests if var is of the string type. var can be any expression allowed by the AviSynth Syntax.

Examples:

IsString("test") = true
IsString(2.3) = false
IsString(String(2.3)) = true

• Exist   |   v2.07   |   Exist(filename)

Tests if the file specified by filename exists.

Examples:

filename = ...
clp = Exist(filename) ? AviSource(filename) : Assert(false, "file: " + filename + " does not exist")

• Defined   |     |   Defined(var)

Tests if var is defined. Can be used inside Script_functions to test if an optional argument has been given an explicit value.

More formally, the function returns false if its argument (normally a function argument or variable) has the void ('undefined') type, otherwise it returns true.

Examples:

b_arg_supplied = Defined(arg)
myvar = b_arg_supplied ? ... : ...

Back to Internal functions.