For - Revision history

Hendricks266 at 19:44, 15 December 2024

2024-12-15T19:44:18Z

← Older revision		Revision as of 12:44, 15 December 2024
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	'''for''' <gamevar> <~~function~~> { [...] }<br>		'''for''' <gamevar> <iterator> { [...] }<br>
	'''for''' <gamevar> <~~function~~> <value> { [...] }		'''for''' <gamevar> <iterator> <value> { [...] }

	Executes the code in the curly braces for every instance of the ~~function~~ specified~~, and~~ <[[gamevar]]> ~~stores~~ the sprite/sector/wall/etc ~~found in~~ the ~~current function~~.		Executes the code in the curly braces for every instance of the iterator specified. The <[[gamevar]]> specified will be set to the index ([[sprite]]/[[sector]]/[[wall]]/etc) for that iteration of execution. (In math, this is called the induction variable.)

	For example, ~~setting~~ <~~function~~> to '''allsprites''' will ~~execute~~ the code for every sprite in-game, and ~~the var specified in~~ <[[gamevar]]> will be set to the ~~sprite~~ number of ~~the current~~ sprite it~~'s on~~.		For example, specifying <iterator> as '''allsprites''' will run the code for every [[sprite]] in the game world, and <[[gamevar]]> will be set to the ID number of one particular sprite when it gets its turn.

	== ~~Functions~~ ==		== Iterators ==

	{\| {{prettytable}}		{\| {{prettytable}}
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	\| '''allwalls''' \|\| All walls in the map.		\| '''allwalls''' \|\| All walls in the map.
	\|-		\|-
	\| '''activelights'''<br />'''lights''' \|\| All active ~~polymer~~ lights.		\| '''activelights'''<br />'''lights''' \|\| All active Polymer lights.
	\|-		\|-
	\| '''drawnsprites''' \|\| Only the sprites currently being drawn.		\| '''drawnsprites''' \|\| Only the sprites currently being drawn.
	\|-		\|-
	\| '''spritesofsector'''<sectnum><br /> '''sprofsec'''<sectnum> \|\| All sprites in the given sector.		\| '''spritesofsector''' <sectnum><br /> '''sprofsec''' <sectnum> \|\| All sprites in the given sector.
	\|-		\|-
	\| '''spritesofstatus''' <statnum><br />'''sprofstat''' <statnum> \|\| All sprites with the given [[statnum]].		\| '''spritesofstatus''' <statnum><br />'''sprofstat''' <statnum> \|\| All sprites with the given [[statnum]].
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	\| '''wallsofsector''' <sectnum><br />'''walofsec''' <sectnum> \|\| The walls of the given sector.		\| '''wallsofsector''' <sectnum><br />'''walofsec''' <sectnum> \|\| The walls of the given sector.
	\|-		\|-
	\| '''loopofwall''' <~~wall num~~> \|\| All walls in the same loop of the given wall.		\| '''loopofwall''' <wallnum> \|\| All walls in the same loop of the given wall.
	\|-		\|-
	\| '''range''' <num> \|\| ~~A range from~~ 0 to the number specified.		\| '''range''' <num> \|\| Every integer starting at 0, up to but not including the number specified.
	\|}		\|}

	Unlike other loop forms, the conditional statement is ''not'' re-evaluated each iteration. For example, the following loop will log 1 through 10:		== Notes ==

			Unlike other loop forms, the implementation keeps its own internal copy of the induction variable, so if <gamevar> is modified in the loop body, the next iteration will take place as if it had not been changed. Similarly, the conditional statement is ''not'' re-evaluated each iteration. For example, the following loop will log 1 through 10:

	var i		var i
	var j 10		var j 10
	for i range j {
	add i 1 // ~~only affects current iteration; log~~ 1..10 instead of 0..9		for i range j
	~~sub j 1~~ // ~~same as above; effectively does nothing in this example~~		{
	~~al i~~		add i 1 // interpret value as 1..10 instead of 0..9
			[[al]] i // write value to the log file

			set j 99999 // useless but harmless operation for demonstration purposes
	}		}

			These factors combined make for loops safer than [[whilevarn]] to use in CON, because it avoids accidentally clobbering the gamevars in states that are called, or events that run during operations performed (such as [[EVENT_SPAWN]] during [[spawn]]).

			For loops are also strongly preferable for performance reasons. Most users only need to remember that fact, but the technical explanation for those interested is that the loop is implemented as an actual for loop in EDuke32's C++ code, where the induction variable and iteration condition are ordinary local variables on the call stack. In contrast, [[whilevarn]] takes place on the level of commands in the CON interpreter, jumping around locations in the compiled bytecode and operating naively on gamevars. The former paradigm is faster because does not have to load and store the gamevar's value to/from memory for every iteration, which places stress on the data cache and could stall due to RAM access delays, and also because CPU branch prediction will be more effective when the meaning of the loop is more plainly stated to the compiler and in the resulting machine code.

	[[Category:EDuke32 specific commands]]		[[Category:EDuke32 specific commands]]

Rob Anybody: Add note about conditional evaluation

2020-07-15T15:12:45Z

Add note about conditional evaluation

@@ Line 29: / Line 29: @@
 | '''range''' <num> || A range from 0 to the number specified.
 |}
 [[Category:EDuke32 specific commands]]

Fox at 11:56, 25 February 2020

2020-02-25T11:56:59Z

← Older revision		Revision as of 04:56, 25 February 2020
Line 2:		Line 2:
	'''for''' <gamevar> <function> <value> { [...] }		'''for''' <gamevar> <function> <value> { [...] }

	Executes the code in the curly braces for every instance of the function specified, and <[[gamevar]]> stores the sprite/sector/wall/etc found in the current function. For example, setting <function> to '''allsprites''' will execute the code for every sprite in-game, and the var specified in <[[gamevar]]> will be set to the sprite number of the current sprite it's on.		Executes the code in the curly braces for every instance of the function specified, and <[[gamevar]]> stores the sprite/sector/wall/etc found in the current function.

			For example, setting <function> to '''allsprites''' will execute the code for every sprite in-game, and the var specified in <[[gamevar]]> will be set to the sprite number of the current sprite it's on.

	== Functions ==		== Functions ==

Fox at 11:56, 25 February 2020

2020-02-25T11:56:45Z

← Older revision		Revision as of 04:56, 25 February 2020
Line 2:		Line 2:
	'''for''' <gamevar> <function> <value> { [...] }		'''for''' <gamevar> <function> <value> { [...] }

	Executes the code in the curly braces for every instance of the ~~iterator~~ specified, and <[[gamevar]]> stores the sprite/sector/wall/etc found in the current ~~iteration~~. For example, setting <~~iterator~~> to '''allsprites''' will execute the code for every sprite in-game, and the var specified in <[[gamevar]]> will be set to the sprite number of the current sprite it's on.		Executes the code in the curly braces for every instance of the function specified, and <[[gamevar]]> stores the sprite/sector/wall/etc found in the current function. For example, setting <function> to '''allsprites''' will execute the code for every sprite in-game, and the var specified in <[[gamevar]]> will be set to the sprite number of the current sprite it's on.

	== Functions ==		== Functions ==

Fox at 11:56, 25 February 2020

2020-02-25T11:56:13Z

← Older revision		Revision as of 04:56, 25 February 2020
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	'''for''' <[[gamevar]]> <~~iterator~~> { ~~code to execute~~ }<br>		'''for''' <gamevar> <function> { [...] }<br>
	'''for''' <[[gamevar]]> <~~iterator~~> <~~num~~> { ~~code to execute~~ }		'''for''' <gamevar> <function> <value> { [...] }

	Executes the code in the curly braces for every instance of the iterator specified, and <[[gamevar]]> stores the sprite/sector/wall/etc found in the current iteration. For example, setting <iterator> to '''allsprites''' will execute the code for every sprite in-game, and the var specified in <[[gamevar]]> will be set to the sprite number of the current sprite it's on.		Executes the code in the curly braces for every instance of the iterator specified, and <[[gamevar]]> stores the sprite/sector/wall/etc found in the current iteration. For example, setting <iterator> to '''allsprites''' will execute the code for every sprite in-game, and the var specified in <[[gamevar]]> will be set to the sprite number of the current sprite it's on.

	~~Iterator types:~~		== Functions ==
	:'''allsprites''' - All actors/sprites in-game.
	:'''allsectors''' - All sectors in the map.		{\| {{prettytable}}
	:'''allwalls''' - All walls in the map.		\| '''allsprites''' \|\| All actors/sprites in-game.
	:'''activelights''' - All active polymer lights.		\|-
	:'''drawnsprites''' - Only the sprites currently being drawn.		\| '''allsectors''' \|\| All sectors in the map.
	:'''spritesofsector <~~sector num~~>''' - All sprites in the given sector.		\|-
	:'''spritesofstatus <statnum>''' - All sprites with the given [[statnum]].		\| '''allwalls''' \|\| All walls in the map.
	:'''wallsofsector <~~sector num~~>''' - The walls of the given sector.		\|-
	:'''loopofwall <wall num>~~''' -~~ All walls in the same loop of the given wall.		\| '''activelights'''<br />'''lights''' \|\| All active polymer lights.
	:'''range <num>~~''' -~~ A range from 0 to the number specified.		\|-
			\| '''drawnsprites''' \|\| Only the sprites currently being drawn.
			\|-
			\| '''spritesofsector'''<sectnum><br /> '''sprofsec'''<sectnum> \|\| All sprites in the given sector.
			\|-
			\| '''spritesofstatus''' <statnum><br />'''sprofstat''' <statnum> \|\| All sprites with the given [[statnum]].
			\|-
			\| '''wallsofsector''' <sectnum><br />'''walofsec''' <sectnum> \|\| The walls of the given sector.
			\|-
			\| '''loopofwall''' <wall num> \|\| All walls in the same loop of the given wall.
			\|-
			\| '''range''' <num> \|\| A range from 0 to the number specified.
			\|}

	[[Category:EDuke32 specific commands]]		[[Category:EDuke32 specific commands]]

StrikerTheHedgefox: Documentation of the "for" CON keyword.

2017-08-24T15:58:20Z

Documentation of the "for" CON keyword.

New page

'''for''' <[[gamevar]]> <iterator> { code to execute }<br>
'''for''' <[[gamevar]]> <iterator> <num> { code to execute }

Executes the code in the curly braces for every instance of the iterator specified, and <[[gamevar]]> stores the sprite/sector/wall/etc found in the current iteration. For example, setting <iterator> to '''allsprites''' will execute the code for every sprite in-game, and the var specified in <[[gamevar]]> will be set to the sprite number of the current sprite it's on.

Iterator types:
:'''allsprites''' - All actors/sprites in-game.
:'''allsectors''' - All sectors in the map.
:'''allwalls''' - All walls in the map.
:'''activelights''' - All active polymer lights.
:'''drawnsprites''' - Only the sprites currently being drawn.
:'''spritesofsector <sector num>''' - All sprites in the given sector.
:'''spritesofstatus <statnum>''' - All sprites with the given [[statnum]].
:'''wallsofsector <sector num>''' - The walls of the given sector.
:'''loopofwall <wall num>''' - All walls in the same loop of the given wall.
:'''range <num>''' - A range from 0 to the number specified.

[[Category:EDuke32 specific commands]]