State - Revision history

Joanne Furlough: Replaced Rand Linden's comment with the latest test of the operation.

2020-06-14T19:57:02Z

Replaced Rand Linden's comment with the latest test of the operation.

← Older revision		Revision as of 12:57, 14 June 2020
Line 109:		Line 109:
	*The ''default'' state must be defined before all others.		*The ''default'' state must be defined before all others.
	*States cannot have user functions or variables inside their immediate scope, only event definitions may be inside a states scope.		*States cannot have user functions or variables inside their immediate scope, only event definitions may be inside a states scope.
	*User-defined (global) functions cannot change a script's state. The compiler will throw the error 'ERROR: Global functions can't change state'. ~~'''Note''': Previously~~, ~~global functions could~~ change ~~state~~ in the body of a simple 'if' statement; this "workaround" no longer ~~works~~.		*User-defined (global) functions cannot change a script's state. The compiler will throw the error 'ERROR: Global functions can't change state'. However, a workaround can be used by putting the state change in the body of a simple 'if' statement; one which is without an 'else' clause (Ex: '''if (condition) state Two;''' rather than '''if (condition) state Two; else state default;'''). Rand Linden has previously stated that this workaround is no longer valid, so care should be taken in using it, and preparations made for the sudden removal of this bugfeature.
	}}		}}

Lady Sumoku: Replaced old block with

2015-01-22T08:54:23Z

Replaced old <LSL> block with <source lang="lsl2">

← Older revision		Revision as of 01:54, 22 January 2015
Line 53:		Line 53:

	{{#vardefine:examples\|		{{#vardefine:examples\|
	<~~lsl~~>		<source lang="lsl2">
	default		default
	{		{
Line 93:		Line 93:
	}		}
	}		}
	</~~lsl~~>		</source>
	* '''[http://www.youtube.com/watch?v=49vj9HEI2OY/Basic Tutorial on States, Events, and Functions]		* '''[http://www.youtube.com/watch?v=49vj9HEI2OY/Basic Tutorial on States, Events, and Functions]
	}}		}}

Omei Qunhua: Clarify conditions for entering default state

2012-12-27T13:02:58Z

Clarify conditions for entering default state

← Older revision		Revision as of 06:02, 27 December 2012
Line 6:		Line 6:
	In LSL, most scripts sit idle until they receive some input, or detect some change in their environment. At any moment, the script is in some state, and will react to events or inputs according to some scheme defined by the programmer. However, a script can also contain two or more different states, and react differently to events or inputs depending on what state it is in.		In LSL, most scripts sit idle until they receive some input, or detect some change in their environment. At any moment, the script is in some state, and will react to events or inputs according to some scheme defined by the programmer. However, a script can also contain two or more different states, and react differently to events or inputs depending on what state it is in.

	The main state is the '''default''' state. When a script is compiled, reset or loaded, this is the state it enters by default. After the default state definition, additional state definitions may follow, which the script may use to change how and which events are handled.		The main state is the '''default''' state. When a script is compiled, reset or loaded, this is the state it enters by default. A script will '''NOT''' automatically re-enter the default state state_entry event when the task is rezzed or attached (even by a new owner), nor if the task is moved to another SIM, nor on SIM restart.

			After the default state definition, additional state definitions may follow, which the script may use to change how and which events are handled.
	</div>		</div>
	</div>		</div>

Omei Qunhua: oops :(

2012-12-27T12:24:16Z

oops :(

← Older revision		Revision as of 05:24, 27 December 2012
Line 69:		Line 69:
	// - that can lead to the next touch_start on return to this state to be missed.		// - that can lead to the next touch_start on return to this state to be missed.
	// Here we do the state change safely, from within touch_end		// Here we do the state change safely, from within touch_end
	state ~~other~~;		state two;
	}		}

Omei Qunhua: typo

2012-12-27T12:21:05Z

typo

← Older revision		Revision as of 05:21, 27 December 2012
Line 67:		Line 67:
	{		{
	// Note: NEVER do a state change from within a touch_start event -		// Note: NEVER do a state change from within a touch_start event -
	// - that can lead to the next touch_start on return to this state to me missed.		// - that can lead to the next touch_start on return to this state to be missed.
	// Here we do the state change safely, from within touch_end		// Here we do the state change safely, from within touch_end
	state other;		state other;

Omei Qunhua: Change example to do state change from touch_end event

2012-12-27T12:19:58Z

Change example to do state change from touch_end event

← Older revision		Revision as of 05:19, 27 December 2012
Line 1:		Line 1:
	~~{{Issues/SVC-3017}}~~{{LSL Header\|ml=*}}		{{LSL Header\|ml=*}}
	{{RightToc}}		{{RightToc}}
	<div id="box">		<div id="box">
Line 6:		Line 6:
	In LSL, most scripts sit idle until they receive some input, or detect some change in their environment. At any moment, the script is in some state, and will react to events or inputs according to some scheme defined by the programmer. However, a script can also contain two or more different states, and react differently to events or inputs depending on what state it is in.		In LSL, most scripts sit idle until they receive some input, or detect some change in their environment. At any moment, the script is in some state, and will react to events or inputs according to some scheme defined by the programmer. However, a script can also contain two or more different states, and react differently to events or inputs depending on what state it is in.

	The main state is the '''default''' state. When a script is compiled, reset or loaded, this is the state it enters by default. After the default state definition ~~can follow~~ additional state definitions which the script may use to change how and which events are handled.		The main state is the '''default''' state. When a script is compiled, reset or loaded, this is the state it enters by default. After the default state definition, additional state definitions may follow, which the script may use to change how and which events are handled.
	</div>		</div>
	</div>		</div>
Line 56:		Line 56:
	state_entry()		state_entry()
	{		{
	~~// PUBLIC_CHANNEL has the integer value 0~~		llSay(0,
	llSay(~~PUBLIC_CHANNEL~~,
	"You either just saved the script after editing it"		"You either just saved the script after editing it"
	+ "\nand/or the script (re)entered the default state.");		+ "\nand/or the script (re)entered the default state.");
Line 65:		Line 64:
	}		}

	~~touch_start~~(integer num_detected)		touch_end(integer num_detected)
	{		{
			// Note: NEVER do a state change from within a touch_start event -
			// - that can lead to the next touch_start on return to this state to me missed.
			// Here we do the state change safely, from within touch_end
	state other;		state other;
	}		}
Line 72:		Line 74:
	state_exit()		state_exit()
	{		{
	llSay(~~PUBLIC_CHANNEL~~, "The script leaves the default state.");		llSay(0, "The script leaves the default state.");
	}		}
	}		}

	state ~~other~~		state two
	{		{
	state_entry()		state_entry()
	{		{
	llSay(~~PUBLIC_CHANNEL~~, "The script entered ~~the other~~ state.");		llSay(0, "The script entered state 'two'");
	state default;		state default;
	}		}
Line 86:		Line 88:
	state_exit()		state_exit()
	{		{
	llSay(~~PUBLIC_CHANNEL~~, "The script leaves ~~the other~~ state.");		llSay(0, "The script leaves state 'two'");
	}		}
	}		}

Kireji Haiku: changed example script

2012-10-05T20:38:09Z

changed example script

← Older revision		Revision as of 13:38, 5 October 2012
Line 51:		Line 51:

	{{#vardefine:examples\|		{{#vardefine:examples\|
	<lsl>default		<lsl>
			default
	{		{
	~~touch_end~~(integer a)		state_entry()
			{
			// PUBLIC_CHANNEL has the integer value 0
			llSay(PUBLIC_CHANNEL,
			"You either just saved the script after editing it"
			+ "\nand/or the script (re)entered the default state.");

			// white and opaque text
			llSetText("Click to change states", <1.0, 1.0, 1.0>, (float)TRUE);
			}

			touch_start(integer num_detected)
	{		{
	state ~~hello~~;		state other;
			}

			state_exit()
			{
			llSay(PUBLIC_CHANNEL, "The script leaves the default state.");
	}		}
	}		}

	state ~~hello~~		state other
	{		{
	state_entry()		state_entry()
	{		{
	~~llOwnerSay~~("~~Hello~~");		llSay(PUBLIC_CHANNEL, "The script entered the other state.");
	state default;		state default;
	}		}

	state_exit()		state_exit()
	{		{
	~~llOwnerSay~~("~~Goodbye~~");		llSay(PUBLIC_CHANNEL, "The script leaves the other state.");
	}		}
	}</lsl>		}
			</lsl>
	* '''[http://www.youtube.com/watch?v=49vj9HEI2OY/Basic Tutorial on States, Events, and Functions]		* '''[http://www.youtube.com/watch?v=49vj9HEI2OY/Basic Tutorial on States, Events, and Functions]
	}}		}}

Strife Onizuka at 18:46, 7 June 2012

2012-06-07T18:46:31Z

← Older revision		Revision as of 11:46, 7 June 2012
Line 32:		Line 32:
	{{LSL DefineRow\|event\|events\|{{#var:p_events_desc}}}}		{{LSL DefineRow\|event\|events\|{{#var:p_events_desc}}}}
	{{!}}}		{{!}}}
	~~'''~~target~~'''~~ state definition.		{{LSLP\|target}} state definition.
	</div>		</div>
	</div>		</div>

Fire Centaur at 04:27, 24 October 2011

2011-10-24T04:27:15Z

← Older revision		Revision as of 21:27, 23 October 2011
Line 71:		Line 71:
	}		}
	}</lsl>		}</lsl>
			* '''[http://www.youtube.com/watch?v=49vj9HEI2OY/Basic Tutorial on States, Events, and Functions]
	}}		}}

Rand Linden at 21:16, 21 September 2011

2011-09-21T21:16:41Z

← Older revision		Revision as of 14:16, 21 September 2011
Line 85:		Line 85:
	*The ''default'' state must be defined before all others.		*The ''default'' state must be defined before all others.
	*States cannot have user functions or variables inside their immediate scope, only event definitions may be inside a states scope.		*States cannot have user functions or variables inside their immediate scope, only event definitions may be inside a states scope.
	*~~In general, states cannot be changed inside of user~~-defined (global) functions. The compiler will throw the error 'ERROR: Global functions can't change state'. ~~However~~, ~~a workaround can be used by putting the~~ state ~~change~~ in the body of a simple 'if' statement; one which is without an 'else' clause (Ex: '''if (condition) state Two;''' rather than '''if (condition) state Two; else state default;'''). This is a missfeature (missfeature: a lava-flowed bug that has turned into something akin to a feature).		*User-defined (global) functions cannot change a script's state. The compiler will throw the error 'ERROR: Global functions can't change state'. '''Note''': Previously, global functions could change state in the body of a simple 'if' statement; this "workaround" no longer works.
	}}		}}