File Boolean.lua
Functions
Boolean:booleanFromString (s) | Obtain boolean value from string representation. |
Boolean:booleanValue (v, dflt) | Get boolean equivalent, or default. |
Boolean:getAsBoolean (a) | Get a boolean from a variable whose type has not been pre-assured. |
Boolean:getBoolean (a, nameToThrow, default) | Determine if a boolean, and if so, return it's value, otherwise return nil. |
Boolean:isBooleanTrue (v) | Determine if value is non-nil, boolean, and true. |
Boolean:isFalse (v) | Determine if the specified boolean is false. |
Boolean:isTrue (v) | Determine if the specified boolean is true. |
Boolean:new (t) | Constructor for new instance. |
Boolean:newClass (t) | Constructor for extending class. |
Functions
- Boolean:booleanFromString (s)
-
Obtain boolean value from string representation.
Parameters:
-
s
:
Usage:
the inverse of 'tostring( booleanValue )'.
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- Boolean:booleanValue (v, dflt)
-
Get boolean equivalent, or default.
Parameters:
-
v
: (any type, required) value to have returned boolean equivalent of. -
dflt
: (boolean, optional) default in case value is nil.
Usage:
always returns boolean true or false, never throws error.
example: switch = bool:booleanValue( myVar, true ) -- return true or false if set, and if unset, return true.
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- Boolean:getAsBoolean (a)
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Get a boolean from a variable whose type has not been pre-assured.
Parameters:
-
a
:
Usage:
If boolean, then returned verbatim, if string, then attempt to convert to boolean, otherwise returns nil.
The intended use is for cases when a boolean is required, but user or legacy code may have left something else where a number is expected, in which case, the old value is to be ignored...
never throws an error.
myBool = bool:getAsBoolean( something ) or false -- assure boolean true or false from boolean or string, else convert nil to false.
myBool = bool:getAsBoolean( something ); if myBool == nil then -- something is not gettable as boolean.
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- Boolean:getBoolean (a, nameToThrow, default)
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Determine if a boolean, and if so, return it's value, otherwise return nil.
Parameters:
-
a
: -
nameToThrow
: -
default
:
Usage:
throws error if not boolean type.
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- Boolean:isBooleanTrue (v)
-
Determine if value is non-nil, boolean, and true.
Parameters:
-
v
:
Usage:
Convenience function for times when a value could be boolean true or something else...
this function will never throw an error.
Return value:
- true iff "all of the above".
-
- Boolean:isFalse (v)
-
Determine if the specified boolean is false.
Parameters:
-
v
:
Usage:
Same as 'not v' except it will throw an error if the value is not a boolean.
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- Boolean:isTrue (v)
-
Determine if the specified boolean is true.
Parameters:
-
v
:
Usage:
Returns the value as is if not nil, else the boolean 'false'. Avoids problem of illegal comparison with nil.
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- Boolean:new (t)
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Constructor for new instance.
Parameters:
-
t
:
-
- Boolean:newClass (t)
-
Constructor for extending class.
Parameters:
-
t
:
-