Add FSM language description

TODO

@@ -1,7 +1,7 @@
 Here is a list of things I plan to implement.
 
 
-[FSM generator](status: in progress)
+[FSM generator](status: after first release)
 Description: A tool which generates circuit based on code. You use special lanugae 
 to describe FSM (finite state machine), and based on this code circuit is 
 generated. Example of the code:
@@ -120,4 +120,23 @@ is input or output. You can add a name, so some tools can use it to name wires
 in code or descriptions. Very userful for Reverse Generator tool.
 Blocks can also be used by generators, so that the player can see which wire is which. 
 
+[undo tool](status: not started)
+Description: a list per user of deleted regions, that can by recovered, or put in 
+a blue book. It's a simple list of
+
+data (before circuit) (after circuit) (position+teleport button) (to book button)
+
+Circuits are stores in files, in minetest data structures (let's cool it 'a trash book')
+is only a list of name s of last deletes.
+
+It will track the following:
+- cable generate (black tool)
+- remove regions and wires (red tools)
+- orange tools
+- grey tool
+- pasting blue books
+- pasting fsm books (orange book)
+
+
+
 

mesecons_autotools/fsm/fsm.lua

@@ -29,6 +29,24 @@ function get_stats_string(data)
   return stats
 end
 
+
+local function get_fromspec_help()
+  local formspec = 
+
+  "formspec_version[3]".. 
+
+  "size[32,25]"..    
+  "style_type[textarea;font=mono]" .. 
+
+  "label[15,0.7;FSM generator]".. 
+  --"label[20,0.7;" .. file .. "]" ..
+
+
+  ""
+  return formspec
+end
+
+
 local function get_formspec(data)
   local code = minetest.formspec_escape(data.code or "")
   local name = minetest.formspec_escape(data.name or "")
@@ -52,6 +70,10 @@ local function get_formspec(data)
   "size[32,25]"..    
   "style_type[textarea;font=mono]" .. 
 
+  "style[question;fgimg=question.png;fgimg_hovered=question_hovered.png;border=false]" ..
+  "image_button[30.8,0.2;1,1;;question;]" ..
+
+
   "label[15,0.7;FSM generator]".. 
   --"label[20,0.7;" .. file .. "]" ..
   "field[0.5,2;15,1;name;Name;" .. name .. "]"..
@@ -74,6 +96,170 @@ local function get_formspec(data)
   return formspec
 end
 
+local help = [==[
+
+
+[General Info]
+This is a Moore State Machine generator.
+
+Each state has a name, built out of the letters (A-Z,a-Z), numbers (0-9), and underscore. Name must begin with a letter.
+
+Each pin has a name, built out of the letters (A-Z,a-Z), numbers (0-9), and underscore. Name must begin with a letter.
+
+[Comments]
+Line that begins with ';' is a comment. White characters at the beginning are ignored.
+
+[Init State]
+Init state is declared with double square bracket '[[' and ']]'. Eg. [[init]], [[init_state]]
+You must have exacly one init state.
+
+You dont have to declare states, just use them in transitions or outputs declarations.
+
+[Transitions]
+Transitions have the following form:
+ [list_of_states] list_of_pins -> [state]
+where 
+ 'list_of_states' is a list of input state names separated by space, list must contain at least one state
+ 'list_of_pins' is a list of pin names separated by space, list can be empty
+ 'state' is output state, ie. next transition state
+
+Eg. 
+ [a] -> [b]
+ [a b] -> [c]
+ [a] pin1 ~pin2 -> [c]
+
+Pins can be negated by ~. If there is no pin on the list, the value of the pin is not considered. [a] -> [b] means go from state 'a' to 'b' no matter what input pins are. [a] p1 -> [b] means, if in state 'a' and inputs pins have the following values: p1='1' and rest input pins have any value, then go to state 'b'. [a] ~p1 -> [b] means, if in state 'a' and pin 'p1' is '0', then go to state 'b' (we dont care about other input pins). [a] p1 ~p2 -> [b] means, if in state 'a' and p1='1' and p2='0' and we dont care about rest pins, then go to state 'b'.
+
+Transition [a b] p1 -> [c] is equivalent to:
+ [a] p1 -> [c]
+ [b] p1 -> [c]
+
+There must be at least one transition. 
+
+[Priority]
+Transitions declared first, have highter priority. If there is more than one transition, that satisfies pin conditions,  only the first one would be applied. 
+
+Eg.
+
+[a] -> [b]
+[a] -> [c]
+
+meas, FSM would go to state 'b'.
+
+Eg. Consider the following situation:
+
+[a] p1 p2 -> [b]
+[a] p1 p3 -> [c]
+
+and pins are (p1,p2,p3)=(1,1,1). Both transitions apply, but because [a] p1 p2 -> [b] is declared first, only this one would be applied, and FSM would transition to sate 'b'.
+
+[Defalut Loop Transition]
+Each state has automatically added self loop transition:
+[state] -> [state]
+This means, that if any of your conditions do not apply, the FSM stays in the same state.
+
+Eg. 
+[a] pin -> [b]
+
+is equivalent to:
+
+[a] pin -> [b]
+[a] -> [a]
+[b] -> [b]
+meaning, if in state 'a' and pin=0 then FSM stays in state 'a'. If in state 'b', stay in state 'b'.
+
+[Outputs]
+Output values are declared as follows:
+ [list_of_states] list_of_pins
+If a pin is on the list, the value is '1'. If the pin is not on the list, the value of this pin is '0'.
+
+Eg.
+ [a] pin1 pin2
+ [a b c] pin_light
+Eg.
+ [a] p1 
+means that when the FSM is in the state 'a' then the output pin 'p1' would have value '1', and the rest of the output pins would have the value '0'.
+Not declared states would automatically have output pins set to '0'.
+
+
+[Fixing Input/Output Order]
+Declaring input/output pins order is optional. You can declare only 'in:', only 'out:', both, or none. If you dont specify input/output pins order, then they are generated automatically, and showed on compilation logs. Syntax is:
+
+in: list_of_pins
+out: list_of_pins
+
+where 'list_of_pins' is a list of pins separated by space.
+
+Eg.
+in: a b d
+out: x y z
+
+[State Groups]
+You can declare state groups as follows:
+
+@group_name = list_of_states
+
+Eg.
+@all = state1 state2 state3
+@gr1 = state1 state2
+@gr2 = state3 state4 state5
+@allgrs = @gr1 @gr2 super_state
+
+You use state group as normal state, but only where multiple states are allowed.
+
+[@all] pin1 ~pin2 -> [state]
+[@all another_state] out1 out2
+
+Eg.
+@gr = s1 s2
+[@gr] -> [b]
+
+is equivalent to:
+
+[s1 s2] -> [b]
+
+which is the same as:
+[s1] -> [b]
+[s2] -> [b]
+
+
+[Pin Groups]
+You can declare pin groups as follows:
+
+#pins = pin1 pin2 ~pin4
+
+and use them as normal pins. You cannot negate it though. 
+
+[a] #pins some_pin -> [b]
+[b] out1 out2 #pins
+
+Eg.
+#pins = p1 ~p2
+[a] #pins p3 -> [b]
+
+is the same as:
+
+[a] p1 ~p2 p3 -> [b]
+
+
+]==]
+local function get_formspec_help()
+  local formspec = 
+  "formspec_version[3]".. 
+
+  "size[32,25]"..    
+  "style_type[textarea;font=mono]" .. 
+
+  "style[question;fgimg=question.png;fgimg_hovered=question_hovered.png;border=false]" ..
+  "style[exit;fgimg=cancel.png;fgimg_hovered=cancel.png;border=false]" ..
+  "image[0.2,0.2;1,1;question.png]" ..
+  "image_button_exit[30.8,0.2;1,1;;exit;]"  ..
+  "textarea[1,2;30,22;;;" .. esc(help) .. "]" .. 
+  ""
+  return formspec
+end
+
+
 function on_place_fsm_book(itemstack, player, pointed_thing)
   local user = player:get_player_name()
   local rad = player:get_look_horizontal()
@@ -133,12 +319,10 @@ function fsm_make_selection(user,file,direction,pos)
 
   if nodes == nil then return end
 
-  
   local sx = nodes.sx
   local sy = nodes.sy
   local sz = nodes.sz
 
-  
   local pos2 = make_pos2(pos,direction,sx,sy,sz)
 
   -- Updatecd 
@@ -151,7 +335,6 @@ end
 
 
 local function on_use_fsm_book(itemstack, player, pointed_thing)
-   
   local user = player:get_player_name()
   local data = itemstack:get_meta():to_table().fields
   local rad = player:get_look_horizontal()
@@ -166,8 +349,6 @@ local function on_use_fsm_book(itemstack, player, pointed_thing)
   end
 
   return nil 
-  
- 
 end
 
 minetest.register_on_player_receive_fields(function(player, formname, fields)
@@ -176,6 +357,14 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
     local stack = player:get_wielded_item()
     local ffields = stack:get_meta():to_table().fields
 
+    if( fields.question ) then
+      local fs = get_formspec_help()
+      minetest.show_formspec(user, "mesecons_autotools:fsm_show", fs) 
+      return
+    end
+
+
+
     local data = {}
     local file = ffields.file