Updated atlac readme to consistently use Markdown formatting

1 files changed, 258 insertions, 146 deletions

diff --git a/advtrains_luaautomation/README.txt b/advtrains_luaautomation/README.txt
index 177bbc9..8f023ae 100644
--- a/advtrains_luaautomation/README.txt
+++ b/advtrains_luaautomation/README.txt
@@ -1,100 +1,133 @@
 
-#### Advtrains - Lua Automation features
+# Advtrains - Lua Automation features
 
-This mod offers components that run LUA code and interface with each other through a global environment. It makes complex automated railway systems possible.
+This mod offers components that run LUA code and interface with each other through a global environment. It makes complex automated railway systems possible. The mod is sometimes abbreviated as 'atlatc'. This stands for AdvTrainsLuaATC. This short name has been chosen for user convenience, since the name of this mod ('advtrains_luaautomation') is very long.
 
-### atlatc
-The mod is sometimes abbreviated as 'atlatc'. This stands for AdvTrainsLuaATC. This short name has been chosen for user convenience, since the name of this mod ('advtrains_luaautomation') is very long.
-
-### Privilege
+## Privileges
 To perform any operations using this mod (except executing operation panels), players need the "atlatc" privilege.
 This privilege should never be granted to anyone except trusted administrators. Even though the LUA environment is sandboxed, it is still possible to DoS the server by coding infinite loops or requesting expotentially growing interrupts. 
 
-### Active and passive
-Active components are these who have LUA code running in them. They are triggered on specific events. Passive components are dumb, they only have a state and can be set to another state, they can't perform actions themselves.
-
-### Environments
+## Environments
 
-Each active component is assigned to an environment. This is where all data are held. Components in different environments can't inferface with each other.
+Each active component is assigned to an environment where all atlac data is held. Components in different environments can't inferface with each other.
 This system allows multiple independent automation systems to run simultaneously without polluting each other's environment.
 
-/env_create <env_name>
-Create environment with the given name. To be able to do anything, you first need to create an environment. Choose the name wisely, you can't change it afterwards.
+ - `/env_create <env_name>`:
+Create environment with the given name. To be able to do anything, you first need to create an environment. Choose the name wisely, you can't change it afterwards without deleting the environment and starting again.
 
-/env_setup <env_name>
+ - `/env_setup <env_name>`:
 Invoke the form to edit the environment's initialization code. For more information, see the section on active components. You can also delete an environment from here.
 
-### Active components
-
-The code of every active component is run on specific events which are explained soon. When run, every variable written that is not local and is no function or userdata is saved over code re-runs and over server restarts. Additionally, the following global variables are defined:
-
-# event
-The variable 'event' contains a table with information on the current event. How this table can look is explained below.
+## Functions and variables
+### General Functions and Variables
+The following standard Lua libraries are available:
+ - `string`
+ - `math`
+ - `table`
+ - `os`
+ 
+The following standard Lua functions are available:
+ - `assert`
+ - `error`
+ - `ipairs`
+ - `pairs`
+ - `next`
+ - `select`
+ - `tonumber`
+ - `tostring`
+ - `type`
+ - `unpack`
+
+Any attempt to overwrite the predefined values results in an error.
+
+## Components and Events
+
+### Components
+Atlac components introduce automation-capable components that fall within two categories:
+ - Active Components are components that are able to run Lua code, triggered by specific events.
+ - Passive Components can't perform actions themselves. Their state can be read and set by active components or manually by the player.
+ 
+
+
+## Functions and Variables
+
+### Events
+The event table is a variable created locally by the component being triggered. It is a table with the following format:
+```lua
+event = {
+	type = "<event type>",
+	<event type> = true,
+	--additional event-specific content
+}
+```
+You can check the event type by using the following:
+```lua 
+if event.type == "wanted" then
+	--do stuff
+end
+```
+or
+```lua
+if event.wanted then
+	--do stuff
+end
+````
+where `wanted` is the event type to check for.  
+See the "Active Components" section below for details on the various event types as not all of them are applicable to all components.
 
-# S
+### LuaAutomation Global Variables
+ - `S`
 The variable 'S' contains a table which is shared between all components of the environment. Its contents are persistent over server restarts. May not contain functions, every other value is allowed.
-Example:
-Component 1: S.stuff="foo"
-Component 2: print(S.stuff)
--> foo
 
-# F
+ - `F`
 The variable 'F' also contains a table which is shared between all components of the environment. Its contents are discarded on server shutdown or when the init code gets re-run. Every data type is allowed, even functions.
 The purpose of this table is not to save data, but to provide static value and function definitions. The table should be populated by the init code.
 
-# Standard Lua functions
-The following standard Lua libraries are available:
-string, math, table, os
-The following standard Lua functions are available:
-assert, error, ipairs, pairs, next, select, tonumber, tostring, type, unpack
-
-Every attempt to overwrite any of the predefined values results in an error.
-
-# LuaAutomation-specific global functions
+### LuaAutomation Global Functions
+> Note: in the following functions, all parameters named `pos` designate a position. You can use the following:  
+> - a default Minetest position vector (eg. {x=34, y=2, z=-18})  
+> - the POS(34,2,-18) shorthand below.  
+> - A string, the passive component name. See 'passive component naming'. 
+  
 
-POS(x,y,z)
-Shorthand function to create a position vector {x=?, y=?, z=?} with less characters
 
-In the following functions, all parameters named 'pos' designate a position. You can use either:
-- a default Minetest position vector (like {x=34, y=2, z=-18})
-- the POS(34,2,-18) shorthand
-- A string, the passive component name. See 'passive component naming'.
+ - `POS(x,y,z)`
+Shorthand function to create a position vector {x=?, y=?, z=?} with less characters.
 
-getstate(pos)
-Get the state of the passive component at position 'pos'. See section on passive components for more info.
-pos can be either a position vector (created by POS()) or a string, the name of this passive component.
+ - `getstate(pos)`
+Get the state of the passive component at position `pos`.
 
-setstate(pos, newstate)
-Set the state of the passive component at position 'pos'.
+ - `setstate(pos, newstate)`
+Set the state of the passive component at position `pos`.
 
-is_passive(pos)
+ - `is_passive(pos)`
 Checks whether there is a passive component at the position pos (and/or whether a passive component with this name exists)
 
-interrupt(time, message)
-Cause LuaAutomation to trigger an 'int' event on this component after the given time in seconds with the specified 'message' field. 'message' can be of any Lua data type.
-Not available in init code!
+ - `interrupt(time, message)`
+Cause LuaAutomation to trigger an `int` event on this component after the given time in seconds with the specified `message` field. `message` can be of any Lua data type. *Not available in init code.*
 
-interrupt_pos(pos, message)
-Immediately trigger an 'ext_int' event on the active component at position pos. 'message' is like in interrupt().
-USE WITH CARE, or better don't use! Incorrect use can result in expotential growth of interrupts.
+ - `interrupt_pos(pos, message)`
+Immediately trigger an `ext_int` event on the active component at position pos. `message` is like in interrupt(). Use with care, or better **_don't use_**! Incorrect use can result in **_expotential growth of interrupts_**.
 
-digiline_send(channel, message)
+ - `digiline_send(channel, message)`
 Make this active component send a digiline message on the specified channel.
-Not available in init code!
+Not available in init code.
 
--- The next 4 functions are available when advtrains_interlocking is enabled: --
+#### Interlocking Route Management Functions
+If `advtrains_interlocking` is enabled, the following aditional functions can be used:
 
-can_set_route(pos, route_name)
+ - `can_set_route(pos, route_name)`
 Returns whether it is possible to set the route designated by route_name from the signal at pos.
 
-set_route(pos, route_name)
+ - `set_route(pos, route_name)`
 Requests the given route from the signal at pos. Has the same effect as clicking "Set Route" in the signalling dialog.
 
-cancel_route(pos)
+ - `cancel_route(pos)`
 Cancels the route that is set from the signal at pos. Has the same effect as clicking "Cancel Route" in the signalling dialog.
 
-get_aspect(pos)
+ - `get_aspect(pos)`
 Returns the signal aspect of the signal at pos. A signal aspect has the following format:
+```lua
 asp = {
 	main = <int speed>,
 		-- Main signal aspect, tells state and permitted speed of next section
@@ -133,6 +166,7 @@ asp = {
 	-- imposed by "speed" fields, until lifted by a value of -1
 	-- (Example: german Langsamfahrstellen-Signale)
 }
+```
 As of January 2020, the 'dst', 'call_on' and 'dead_end' fields are not used.
 
 # Lines
@@ -175,95 +209,128 @@ Functions are run in the environment of the currently active node, regardless of
 
 The 'event' table of the init code is always {type="init", init=true}.
 
-# ATC rails
-The Lua-controlled ATC rails are the only components that can actually interface with trains. The following event types are generated:
-
+### Active Component
+#### Lua ATC Rails
+Lua ATC rails are the only components that can actually interface with trains. The following event types are available to the Lua ATC rails:
+ - ```lua
 {type="train", train=true, id="<train_id>"}
-This event is fired when a train enters the rail. The field 'id' is the unique train ID, which is 6-digit random numerical string.
-If the world contains trains from an older advtrains version, this string may be longer and contain a dot (.)
+```
+	* This event is fired when a train enters the rail. The field `id` is the unique train ID, which is 6-digit random numerical string.
+	* If the world contains trains from an older advtrains version, this string may be longer and contain a dot `.`
 
+ - ```lua
 {type="int", int=true, msg=<message>}
-Fired when an interrupt set by the 'interrupt' function runs out. 'message' is the message passed to the interrupt function.
-For backwards compatiblity reasons, <message> is also contained in an event.message field.
+```
+	* Fired when an interrupt set by the `interrupt` function runs out. `<message>` is the message passed to the interrupt function.
+	* For backwards compatiblity reasons, `<message>` is also contained in an `event.message` variable.
+
+ - ```lua
 {type="ext_int", ext_int=true, message=<message>}
-Fired when another node called 'interrupt_pos' on this position. 'message' is the message passed to the interrupt_pos function.
+```
+	* Fired when another node called `interrupt_pos` on this position. `message` is the message passed to the interrupt_pos function.
 
+ - ```lua
 {type="digiline", digiline=true, channel=<channel>, msg=<message>}
-Fired when the controller receives a digiline message.
+```
+	* Fired when the controller receives a digiline message.
+
+##### Basic Lua Rail Functions and Variables
+In addition to the above environment functions, the following functions are available to whilst the train is in contact with the LuaATC rail:
 
-In addition to the default environment functions, the following functions are available:
+ - `atc_send(<atc_command>)`
+	Sends the specified ATC command to the train (a string) and returns true. If there is no train, returns false and does nothing. See [atc_command.txt](../atc_command.txt) for the ATC command syntax.
 
-atc_send(<atc_command>)
-	Sends the specified ATC command to the train and returns true. If there is no train, returns false and does nothing.
-atc_reset()
+ - `atc_reset()`
 	Resets the train's current ATC command. If there is no train, returns false and does nothing.
-atc_arrow
+
+ - `atc_arrow`
 	Boolean, true when the train is driving in the direction of the arrows of the ATC rail. Nil if there is no train.
-atc_id
+
+ - `atc_id`
 	Train ID of the train currently passing the controller. Nil if there's no train.
-atc_speed
+
+ - `atc_speed`
 	Speed of the train, or nil if there is no train.
-atc_set_text_outside(text)
-	Set text shown on the outside of the train. Pass nil to show no text.
-atc_set_text_inside(text)
-	Set text shown to train passengers. Pass nil to show no text.
-get_line()
+
+ - `atc_set_text_outside(text)`
+	Set text shown on the outside of the train. Pass nil to show no text. `text` must be a string.
+
+ - `atc_set_text_inside(text)`
+	Set text shown to train passengers. Pass nil to show no text. `text` must be a string.
+
+ - `get_line()`
 	Returns the "Line" property of the train (a string).
 	This can be used to distinguish between trains of different lines and route them appropriately.
 	The interlocking system also uses this property for Automatic Routesetting.
-set_line(line)
+
+ - `set_line(line)`
 	Sets the "Line" property of the train (a string).
-	If the first digit of this string is a number (0-9), any subway wagons on the train will have this one displayed as line number
+	If the first digit of this string is a number (0-9), any subway wagons on the train (from advtrains_train_subway) will have this one displayed as line number
 	(where "0" is actually shown as Line 10 on the train)
-get_rc()
+
+ - `get_rc()`
 	Returns the "Routingcode" property of the train (a string).
 	The interlocking system uses this property for Automatic Routesetting.
-set_rc(routingcode)
+
+ - `set_rc(routingcode)`
 	Sets the "Routingcode" property of the train (a string).
 	The interlocking system uses this property for Automatic Routesetting.
-split_at_index(index, command)
-	Splits the train at the specified index, into a train with index-1 wagons and a second train starting with the index-th wagon.
-	command specifies an atc command to be sent to the second train after decoupling.
-split_at_fc(command, len)
-	Splits the train in such a way that all cars with non-empty
-	current FC of the first part of the train have the same FC. The
-	command specified is sent to the rear part, as with
-	split_at_index.  It returns the fc of the cars of the first part.
-
-	The optional argument len specifies the maximum length for the
-	first part of the train. Say, we have len=3, and the train has ""
-	"" "foo" "foo" "foo" "bar", then the first train part will be ""
-	"" "foo".
-
-	Example : Train has current FCs "" "" "foo" "bar" "foo"
-	Result: first train: "" "" "foo"; second train: "bar" "foo"
-	The command returns "foo" in this case
-split_off_locomotive(command, len)
+
+##### Shunting Functions and Variables
+There are several functions available especially for shunting operations. Some of these functions make use of Freight Codes (FC) set in the Wagon Properties of each wagon and/or locomotive:
+
+ - `split_at_index(index, atc_command)`
+	Splits the train at the specified index, into a train with index-1 wagons and a second train starting with the index-th wagon. The `atc_command` specified is sent to the second train after decoupling. `"S0"` or `"B0"` is common to ensure any locomotives in the remaining train don't continue to move.
+	
+	Example: train has wagons `"foo","foo","foo","bar","bar","bar"`  
+	Command: `split_at_index(4,"S0")`  
+	Result: first train (continues at previous speed): `"foo","foo","foo"`, second train (slows at S0): `"bar","bar","bar"`
+
+ - `split_at_fc(atc_command, len)`
+	Splits the train in such a way that all cars with non-empty current FC of the first part of the train have the same FC. The
+	`atc_command` specified is sent to the rear part, as with	split_at_index. It returns the fc of the cars of the first part.
+	
+	Example : Train has current FCs `"" "" "bar" "foo" "bar"`  
+	Command: `split_at_fc(<atc_command>)`  
+	Result: `train "" "" "bar"` and `train "foo" "bar"`  
+	The function returns `"bar"` in this case.
+
+	The optional argument `len` specifies the maximum length for the
+	first part of the train.  
+	Example: Train has current FCs `"foo" "foo" "foo" "foo" "bar" "bar"`  
+	Command: `split_at_fc(<atc_command>,3)`  
+	Result: `"foo" "foo" "foo"` and `"foo" "bar" "bar"`  
+	The function returns `"foo"` in this case.
+
+	
+
+ - `split_off_locomotive(command, len)`
 	Splits off the locomotives at the front of the train, which are
-	identified by an empty FC.  command specifies the command to be
-	executed by the rear half of the train.
-
-	The optional argument len specifies the maximum length for the
-	first part of the train. Say, we have len=3, and the train has ""
-	"" "foo" "foo" "foo" "bar", then the first train part will be ""
-	"" "foo".	
-step_fc()
+	identified by an empty FC. `command` specifies the ATC command to be
+	executed by the rear half of the train. The optional argument `len` specifies the maximum length for the
+	first part of the train as above.
+
+ - `step_fc()`
 	Steps the FCs of all train cars forward. FCs are composed of codes
-	separated by exclamation marks (!), for instance
-	"foo!bar!baz". Each wagon has a current FC, indicating its next
+	separated by exclamation marks (`!`), for instance
+	`"foo!bar!baz"`. Each wagon has a current FC, indicating its next
 	destination. Stepping the freight code forward, selects the next
 	code after the !. If the end of the string is reached, then the
 	first code is selected, except if the string ends with a question
-	mark, then the order is reversed.
+	mark (`?`), then the order is reversed.
+
 
-train_length()
-	returns the number of cars the train is composed of
-set_autocouple()
-	Sets the train into autocouple mode 
-unset_autocouple()
+ - `train_length()`
+	returns the number of cars the train is composed of.
+
+ - `set_autocouple()`
+	Sets the train into autocouple mode. The train will couple to the next train it collides with.
+
+ - `unset_autocouple()`
 	Unsets autocouple mode
 
-set_shunt(), unset_shunt()
+Deprecated:
+ - `set_shunt()`, `unset_shunt()`
 	deprecated aliases for set_autocouple() and unset_autocouple(), will be removed from a later release.
 
 -- This additional function is available when advtrains_interlocking is enabled: --
@@ -302,43 +369,88 @@ In the context of approach callbacks, one more function is available:
 atc_set_lzb_tsr(speed)
 	Impose a Temporary Speed Restriction at the location of this rail, making the train pass this rail at the specified speed. (Causes the same behavior as the TSR rail)
 
-# Operator panel
-This simple node executes its actions when punched. It can be used to change a switch and update the corresponding signals or similar applications.
+##### Timetable Automation
+
+The advtrains_line_automation component adds a few contraptions that should make creating timeable systems easier.
+Part of its functionality is also available in LuaATC:
+
+- `rwt.*`
+All Railway Time functions are included as documented in https://advtrains.de/wiki/doku.php?id=dev:lines:rwt
+
+- `schedule(rw_time, msg)`
+- `schedule_in(rw_dtime, msg)`
+Schedules the following event `{type="schedule", schedule=true, msg=msg}` at (resp. after) the specified railway time (which can be in any format). You can only schedule one event this way. Uses the new lines-internal scheduler.
+
+#### Operator panel
+This simple node executes its actions when punched. It can be used to change a switch and update the corresponding signals or similar applications. It can also be connected to by the`digilines` mod.
+
+The event fired is `{type="punch", punch=true}` by default. In case of an interrupt or a digiline message, the events are similar to the ones of the ATC rail.
+
+#### Init code
+The initialization code is not a component as such, but rather a part of the whole environment. It can (and should) be used to make definitions that other components can refer to.  
+A basic example function to define behavior for trains in stations:
+```lua
+function F.station(station_name)
+	if event.train then
+		atc_send("B0WOL")
+		atc_set_text_inside(station_name)
+		interrupt(10,"depart")
+	end
+	if event.int and event.message="depart" then
+		atc_set_text_inside("") --an empty string clears the displayed text
+		atc_send("OCD1SM")
+	end
+end
+````
+
+The corresponding Lua ATC Rail(s) would then contain the following or similar:  
+````lua
+F.station("Main Station")
+````
 
-The event fired is {type="punch", punch=true} by default. In case of an interrupt or a digiline message, the events are similar to the ones of the ATC rail.
+The init code is run whenever the F table needs to be refilled with data. This is the case on server startup and whenever the init code is changed and you choose to run it.
+The event table of the init code is always `{type="init", init=true}` and can not be anything else.  
+Functions are run in the environment of the currently active node, regardless of where they were defined.
 
 ### Passive components
 
-All passive components can be interfaced with the setstate and getstate functions(see above).
-Below, each apperance is mapped to the "state" of that node.
+All passive components can be interfaced with the `setstate()` and `getstate()` functions (see above).
+Each node below has been mapped to specific "states":
 
-## Signals
-The light signals are interfaceable, the analog signals are not.
-"green" - Signal shows green light
-"red" - Signal shows red light
+#### Signals
+The red/green light signals `advtrains:signal_on/off` are interfaceable. Others such as `advtrains:retrosignal_on/off` are not. If advtrains_interlocking is enabled, trains will obey the signal if the influence point is set.
+ - "green" - Signal shows green light
+ - "red" - Signal shows red light
 
-## Switches
-All default rail switches are interfaceable, independent of orientation.
-"cr" - The switch is set in the direction that is not straight.
-"st" - The switch is set in the direction that is straight.
+#### Switches/Turnouts
+All default rail switches are interfaceable, independent of orientation.  
+ - "cr" The switch is set in the direction that is not straight.
+ - "st" The switch is set in the direction that is straight.
 
-## Mesecon Switch
-The Mesecon switch can be switched using LuaAutomation. Note that this is not possible on levers, only the full-node 'Switch' block.
-"on" - the switch is switched on
-"off" - the switch is switched off
+The "Y" and "3-Way" switches have custom states. Looking from the convergence point:
+ - "l" The switch is set towards the left.
+ - "c" The switch is set towards the center (3-way only).
+ - "r" The switch is set towards the right.
 
-##Andrew's Cross
-"on" - it blinks
-"off" - it does not blink
 
-### Passive component naming
+#### Mesecon Switch
+The Mesecon switch can be switched using LuaAutomation. Note that this is not possible on levers or protected mesecon switches, only the unprotected full-node 'Switch' block `mesecons_switch:mesecon_switch_on/off`.
+ - "on" - the switch is switched on.
+ - "off" - the switch is switched off.
+
+#### Andrew's Cross
+ - "on" - it blinks.
+ - "off" - it does not blink.
+
+#### Passive Component Naming
 You can assign names to passive components using the Passive Component Naming tool.
-Once you set a name for any component, you can reference it by that name in the getstate() and setstate() functions, like this:
-(Imagine a signal that you have named "Stn_P1_out" at position (1,2,3) )
-setstate("Stn_P1_out", "green") instead of setstate(POS(1,2,3), "green")
+Once you set a name for any component, you can reference it by that name in the `getstate()` and `setstate()` functions.  
 This way, you don't need to memorize positions.
 
-PC-Naming can also be used to name interlocking signals for route setting via the set_route() functions. IMPORTANT: The "Signal Name" set in the
-signalling formspec is completely independent and can NOT be used to look up the position, you need to explicitly use the PCNaming tool.
+Example: signal named `"Stn_P1_out"` at `(1,2,3)`  
+Use `setstate("Stn_P1_out", "green")` instead of `setstate(POS(1,2,3), "green")`
+
+If `advtrains_interlocking` is enabled, PC-Naming can also be used to name interlocking signals for route setting via the `set_route()` functions.  
+**Important**: The "Signal Name" field in the signalling formspec is completely independent from PC-Naming and can't be used to look up the position. You need to explicitly use the PC-Naming tool.
 
 --TODO: Ein paar mehr Codebeispiele wären schön, insbesondere mit os.date und so...