Finite state machine: Difference between revisions

Line 1,758:

=={{header|Phix}}==

~~enum~~ ~~READY~~, ~~WAITING~~, ~~DISPENSE~~, ~~REFUND~~, ~~QUIT~~ -- (~~or just use strings if you prefer~~)

You can run this online [http://phix.x10.mx/p2js/fsm.htm here].

⚫

⚫

~~integer~~ ~~state~~ = ~~READY~~, ch = ~~' '~~

while <span~~ style~~="color~~: ~~#004600~~;">~~true do

--

-- demo\rosetta\Finite_State_Machine.exw

⚫

~~printf~~(1,~~"%c\n"~~,ch)

-- =====================================

⚫

~~switch~~ ~~state~~ do

--

⚫

~~case~~ ~~READY~~: ~~printf~~(1,"~~Machine~~ ~~is READY. (D)eposit or (Q)uit~~ :")

~~while true~~ do

with javascript_semantics

-- First, let's define our state machine textually, why not:

⚫

ch = upper(~~wait_key~~())

if ~~ch='D' then state~~ = ~~WAITING exit end if~~

constant state_string = """

Ready,Deposit->Waiting,Quit

⚫

if ch=~~'Q'~~ ~~then~~ ~~state~~ = ~~QUIT~~ ~~exit~~ ~~end~~ if

Waiting,Select->Dispense,Refund

⚫

end ~~while~~

Dispense,Remove->Ready:Remove product

Refund->Ready:Refunding money

⚫

~~case~~ ~~WAITING:~~ ~~printf~~(1,~~"(S)elect product or choose to (R)efund :"~~)

Quit:Bye

⚫

~~while~~ ~~true~~ do

"""

⚫

ch = ~~upper~~(~~wait_key~~())

⚫

if ~~ch~~=~~'S'~~ ~~then~~ ~~state~~ = ~~DISPENSE~~ ~~exit~~ ~~end~~ if

if ch=~~'R' then~~ ~~state~~ ~~= REFUND exit end if~~

function decode(string state_string)

~~end~~ ~~while~~

sequence states = {},

⚫

messages = {},

~~case~~ ~~DISPENSE~~~~:~~ ~~printf~~~~(1~~~~<span~~ ~~style="color: #0000FF;">,"Dispensing product..."~~)

valid_keys = {}

~~printf~~(1,"~~Please (C)ollect product. :~~")

for line in split(state_string,"\n") do

~~while~~ ~~true~~ do

sequence state = {}

ch = ~~upper~~~~<span~~ ~~style="color: #0000FF;">(~~~~wait_key())~~

string keyable = ""

if ch=~~'C'~~ ~~then~~ ~~state~~ = ~~READY~~ exit end if

integer m = find(':',line)

messages = append(messages,iff(m?line[m+1..$]:""))

⚫

end ~~while~~

for phrase in split(line[1..m-1],",") do

~~case~~ ~~REFUND~~: ~~printf~~(1,"~~Please collect refund.~~")

state = append(state,split(phrase,"->"))

~~state~~ = ~~READY~~

keyable &= phrase[1]

ch ~~= ' '~~

end for

⚫

states = append(states,state)

~~case~~ ~~QUIT~~: ~~printf~~(1,~~"Thank you, shutting down now.\n"~~)

valid_keys = append(valid_keys,keyable[2..$])

~~exit~~

end for

~~end~~ ~~switch~~

return {states, messages, valid_keys}

end ~~while~~

end function

constant {states, messages, valid_keys} = decode(state_string),

⚫

valid_states = vslice(vslice(states,1),1)

include pGUI.e

Ihandle dlg, vbox, state, status, options

⚫

procedure transition_to(integer sdx)

IupSetAttribute(status,"TITLE",messages[sdx])

⚫

if length(states[sdx][1])=2 then -- (implicit)

sdx = find(states[sdx][1][2],valid_states)

⚫

end if

IupSetAttribute(state,"TITLE",valid_states[sdx])

IupSetStrAttribute(options,"TITLE",join(vslice(states[sdx][2..$],1)," or "))

end procedure

function finite_state_machine(atom c)

integer sdx = find(IupGetAttribute(state,"TITLE"),valid_states),

⚫

cdx = find(c,valid_keys[sdx])

⚫

if cdx then

⚫

string newstate = states[sdx][cdx+1][$]

⚫

sdx = find(newstate,valid_states)

transition_to(sdx)

⚫

end if

return iff(valid_states[sdx]=`Quit`?IUP_CLOSE:IUP_CONTINUE)

end function

function key_cb(Ihandle /*dlg*/, atom c)

if c=K_ESC then return IUP_CLOSE end if -- (standard practice for me)

if c=K_F5 then return IUP_DEFAULT end if -- (let browser reload work)

⚫

return finite_state_machine(upper(c))

end function

IupOpen()

⚫

state = IupLabel("","EXPAND=YES")

status = IupLabel("","EXPAND=YES")

options = IupLabel("","EXPAND=YES")

vbox = IupVbox({state,status,options},`MARGIN=40x40`)

dlg = IupDialog(vbox,`TITLE="Finite State Machine",SIZE=200x100`)

IupSetCallback(dlg,"KEY_CB",Icallback("key_cb"))

transition_to(1) -- Ready

IupShow(dlg)

if platform()!=JS then

IupMainLoop()

IupHide(dlg)

end if

<pre>

Machine is READY. (D)eposit or (Q)uit :D

(S)elect product or choose to (R)efund :S

Dispensing product...Please (C)ollect product. :C

Machine is READY. (D)eposit or (Q)uit :D

(S)elect product or choose to (R)efund :R

Please collect refund.

Machine is READY. (D)eposit or (Q)uit :Q

Thank you, shutting down now.

</pre>

=={{header|PicoLisp}}==

@@ Line 1,758: / Line 1,758: @@
 =={{header|Phix}}==
+{{libheader|Phix/pGUI}}
-<!--<lang Phix>(notonline)-->
+{{libheader|Phix/online}}
- <span style="color: #008080;">enum</span> <span style="color: #000000;">READY</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">WAITING</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">DISPENSE</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">REFUND</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">QUIT</span>  <span style="color: #000080;font-style:italic;">-- (or just use strings if you prefer)</span>
+You can run this online [http://phix.x10.mx/p2js/fsm.htm here].
+<!--<lang Phix>(phixonline)-->
- <span style="color: #004080;">integer</span> <span style="color: #000000;">state</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">READY</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ch</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">' '</span>
- <span style="color: #008080;">while</span> <span style="color: #004600;">true</span> <span style="color: #008080;">do</span>
+ <span style="color: #000080;font-style:italic;">--
+ -- demo\rosetta\Finite_State_Machine.exw
-     <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%c\n"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">ch</span><span style="color: #0000FF;">)</span>
+ -- =====================================
-     <span style="color: #008080;">switch</span> <span style="color: #000000;">state</span> <span style="color: #008080;">do</span>
+ --</span>
-         <span style="color: #008080;">case</span> <span style="color: #000000;">READY</span><span style="color: #0000FF;">:</span>     <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Machine is READY. (D)eposit or (Q)uit :"</span><span style="color: #0000FF;">)</span>
-                         <span style="color: #008080;">while</span> <span style="color: #004600;">true</span> <span style="color: #008080;">do</span>
+ <span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
+ <span style="color: #000080;font-style:italic;">-- First, let's define our state machine textually, why not:</span>
-                             <span style="color: #000000;">ch</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">upper</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">wait_key</span><span style="color: #0000FF;">())</span>
-                             <span style="color: #008080;">if</span> <span style="color: #000000;">ch</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'D'</span> <span style="color: #008080;">then</span> <span style="color: #000000;">state</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">WAITING</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
+ <span style="color: #008080;">constant</span> <span style="color: #000000;">state_string</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"""
+ Ready,Deposit-&gt;Waiting,Quit
-                             <span style="color: #008080;">if</span> <span style="color: #000000;">ch</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'Q'</span> <span style="color: #008080;">then</span> <span style="color: #000000;">state</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">QUIT</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
+ Waiting,Select-&gt;Dispense,Refund
-                         <span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
+ Dispense,Remove-&gt;Ready:Remove product
+ Refund-&gt;Ready:Refunding money
-         <span style="color: #008080;">case</span> <span style="color: #000000;">WAITING</span><span style="color: #0000FF;">:</span>   <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"(S)elect product or choose to (R)efund :"</span><span style="color: #0000FF;">)</span>
+ Quit:Bye
-                         <span style="color: #008080;">while</span> <span style="color: #004600;">true</span> <span style="color: #008080;">do</span>
+ """</span>
-                             <span style="color: #000000;">ch</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">upper</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">wait_key</span><span style="color: #0000FF;">())</span>
-                             <span style="color: #008080;">if</span> <span style="color: #000000;">ch</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'S'</span> <span style="color: #008080;">then</span> <span style="color: #000000;">state</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">DISPENSE</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
-                             <span style="color: #008080;">if</span> <span style="color: #000000;">ch</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'R'</span> <span style="color: #008080;">then</span> <span style="color: #000000;">state</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">REFUND</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
+ <span style="color: #008080;">function</span> <span style="color: #000000;">decode</span><span style="color: #0000FF;">(</span><span style="color: #004080;">string</span> <span style="color: #000000;">state_string</span><span style="color: #0000FF;">)</span>
-                         <span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
+     <span style="color: #004080;">sequence</span> <span style="color: #000000;">states</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{},</span>
+            <span style="color: #000000;">messages</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{},</span>
-         <span style="color: #008080;">case</span> <span style="color: #000000;">DISPENSE</span><span style="color: #0000FF;">:</span>  <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Dispensing product..."</span><span style="color: #0000FF;">)</span>
+          <span style="color: #000000;">valid_keys</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span>
-                         <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Please (C)ollect product. :"</span><span style="color: #0000FF;">)</span>
+     <span style="color: #008080;">for</span> <span style="color: #000000;">line</span> <span style="color: #008080;">in</span> <span style="color: #7060A8;">split</span><span style="color: #0000FF;">(</span><span style="color: #000000;">state_string</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\n"</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
-                         <span style="color: #008080;">while</span> <span style="color: #004600;">true</span> <span style="color: #008080;">do</span>
+         <span style="color: #004080;">sequence</span> <span style="color: #000000;">state</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span>
-                             <span style="color: #000000;">ch</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">upper</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">wait_key</span><span style="color: #0000FF;">())</span>
+         <span style="color: #004080;">string</span> <span style="color: #000000;">keyable</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">""</span>
-                             <span style="color: #008080;">if</span> <span style="color: #000000;">ch</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'C'</span> <span style="color: #008080;">then</span> <span style="color: #000000;">state</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">READY</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
+         <span style="color: #004080;">integer</span> <span style="color: #000000;">m</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #008000;">':'</span><span style="color: #0000FF;">,</span><span style="color: #000000;">line</span><span style="color: #0000FF;">)</span>
+         <span style="color: #000000;">messages</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">messages</span><span style="color: #0000FF;">,</span><span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">m</span><span style="color: #0000FF;">?</span><span style="color: #000000;">line</span><span style="color: #0000FF;">[</span><span style="color: #000000;">m</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">..$]:</span><span style="color: #008000;">""</span><span style="color: #0000FF;">))</span>
-                         <span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
+         <span style="color: #008080;">for</span> <span style="color: #000000;">phrase</span> <span style="color: #008080;">in</span> <span style="color: #7060A8;">split</span><span style="color: #0000FF;">(</span><span style="color: #000000;">line</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">..</span><span style="color: #000000;">m</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">],</span><span style="color: #008000;">","</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
-         <span style="color: #008080;">case</span> <span style="color: #000000;">REFUND</span><span style="color: #0000FF;">:</span>    <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Please collect refund."</span><span style="color: #0000FF;">)</span>
+             <span style="color: #000000;">state</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">state</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">split</span><span style="color: #0000FF;">(</span><span style="color: #000000;">phrase</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"-&gt;"</span><span style="color: #0000FF;">))</span>
-                         <span style="color: #000000;">state</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">READY</span>
+             <span style="color: #000000;">keyable</span> <span style="color: #0000FF;">&=</span> <span style="color: #000000;">phrase</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span>
-                         <span style="color: #000000;">ch</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">' '</span>
+         <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
+         <span style="color: #000000;">states</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">states</span><span style="color: #0000FF;">,</span><span style="color: #000000;">state</span><span style="color: #0000FF;">)</span>
-         <span style="color: #008080;">case</span> <span style="color: #000000;">QUIT</span><span style="color: #0000FF;">:</span>      <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Thank you, shutting down now.\n"</span><span style="color: #0000FF;">)</span>
+         <span style="color: #000000;">valid_keys</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">valid_keys</span><span style="color: #0000FF;">,</span><span style="color: #000000;">keyable</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">..$])</span>
-                         <span style="color: #008080;">exit</span>
+     <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
-     <span style="color: #008080;">end</span> <span style="color: #008080;">switch</span>
+     <span style="color: #008080;">return</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">states</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">messages</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">valid_keys</span><span style="color: #0000FF;">}</span>
- <span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
+ <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
+ <span style="color: #008080;">constant</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">states</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">messages</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">valid_keys</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">decode</span><span style="color: #0000FF;">(</span><span style="color: #000000;">state_string</span><span style="color: #0000FF;">),</span>
+           <span style="color: #000000;">valid_states</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">vslice</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">vslice</span><span style="color: #0000FF;">(</span><span style="color: #000000;">states</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">),</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
+ <span style="color: #008080;">include</span> <span style="color: #000000;">pGUI</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span>
+ <span style="color: #004080;">Ihandle</span> <span style="color: #000000;">dlg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">vbox</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">status</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">options</span>
+ <span style="color: #008080;">procedure</span> <span style="color: #000000;">transition_to</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">sdx</span><span style="color: #0000FF;">)</span>
+     <span style="color: #7060A8;">IupSetAttribute</span><span style="color: #0000FF;">(</span><span style="color: #000000;">status</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"TITLE"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">messages</span><span style="color: #0000FF;">[</span><span style="color: #000000;">sdx</span><span style="color: #0000FF;">])</span>
+     <span style="color: #008080;">if</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">states</span><span style="color: #0000FF;">[</span><span style="color: #000000;">sdx</span><span style="color: #0000FF;">][</span><span style="color: #000000;">1</span><span style="color: #0000FF;">])=</span><span style="color: #000000;">2</span> <span style="color: #008080;">then</span> <span style="color: #000080;font-style:italic;">-- (implicit)</span>
+         <span style="color: #000000;">sdx</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">states</span><span style="color: #0000FF;">[</span><span style="color: #000000;">sdx</span><span style="color: #0000FF;">][</span><span style="color: #000000;">1</span><span style="color: #0000FF;">][</span><span style="color: #000000;">2</span><span style="color: #0000FF;">],</span><span style="color: #000000;">valid_states</span><span style="color: #0000FF;">)</span>
+     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
+     <span style="color: #7060A8;">IupSetAttribute</span><span style="color: #0000FF;">(</span><span style="color: #000000;">state</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"TITLE"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">valid_states</span><span style="color: #0000FF;">[</span><span style="color: #000000;">sdx</span><span style="color: #0000FF;">])</span>
+     <span style="color: #7060A8;">IupSetStrAttribute</span><span style="color: #0000FF;">(</span><span style="color: #000000;">options</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"TITLE"</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">vslice</span><span style="color: #0000FF;">(</span><span style="color: #000000;">states</span><span style="color: #0000FF;">[</span><span style="color: #000000;">sdx</span><span style="color: #0000FF;">][</span><span style="color: #000000;">2</span><span style="color: #0000FF;">..$],</span><span style="color: #000000;">1</span><span style="color: #0000FF;">),</span><span style="color: #008000;">" or "</span><span style="color: #0000FF;">))</span>
+ <span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
+ <span style="color: #008080;">function</span> <span style="color: #000000;">finite_state_machine</span><span style="color: #0000FF;">(</span><span style="color: #004080;">atom</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">)</span>
+     <span style="color: #004080;">integer</span> <span style="color: #000000;">sdx</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">IupGetAttribute</span><span style="color: #0000FF;">(</span><span style="color: #000000;">state</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"TITLE"</span><span style="color: #0000FF;">),</span><span style="color: #000000;">valid_states</span><span style="color: #0000FF;">),</span>
+             <span style="color: #000000;">cdx</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">c</span><span style="color: #0000FF;">,</span><span style="color: #000000;">valid_keys</span><span style="color: #0000FF;">[</span><span style="color: #000000;">sdx</span><span style="color: #0000FF;">])</span>
+     <span style="color: #008080;">if</span> <span style="color: #000000;">cdx</span> <span style="color: #008080;">then</span>
+         <span style="color: #004080;">string</span> <span style="color: #000000;">newstate</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">states</span><span style="color: #0000FF;">[</span><span style="color: #000000;">sdx</span><span style="color: #0000FF;">][</span><span style="color: #000000;">cdx</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">][$]</span>
+         <span style="color: #000000;">sdx</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">newstate</span><span style="color: #0000FF;">,</span><span style="color: #000000;">valid_states</span><span style="color: #0000FF;">)</span>
+         <span style="color: #000000;">transition_to</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sdx</span><span style="color: #0000FF;">)</span>
+     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
+     <span style="color: #008080;">return</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">valid_states</span><span style="color: #0000FF;">[</span><span style="color: #000000;">sdx</span><span style="color: #0000FF;">]=</span><span style="color: #008000;">`Quit`</span><span style="color: #0000FF;">?</span><span style="color: #004600;">IUP_CLOSE</span><span style="color: #0000FF;">:</span><span style="color: #004600;">IUP_CONTINUE</span><span style="color: #0000FF;">)</span>
+ <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
+ <span style="color: #008080;">function</span> <span style="color: #000000;">key_cb</span><span style="color: #0000FF;">(</span><span style="color: #004080;">Ihandle</span> <span style="color: #000080;font-style:italic;">/*dlg*/</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">)</span>
+     <span style="color: #008080;">if</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">=</span><span style="color: #004600;">K_ESC</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #004600;">IUP_CLOSE</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #000080;font-style:italic;">-- (standard practice for me)</span>
+     <span style="color: #008080;">if</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">=</span><span style="color: #004600;">K_F5</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #004600;">IUP_DEFAULT</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #000080;font-style:italic;">-- (let browser reload work)</span>
+     <span style="color: #008080;">return</span> <span style="color: #000000;">finite_state_machine</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">upper</span><span style="color: #0000FF;">(</span><span style="color: #000000;">c</span><span style="color: #0000FF;">))</span>
+ <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
+ <span style="color: #7060A8;">IupOpen</span><span style="color: #0000FF;">()</span>
+ <span style="color: #000000;">state</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupLabel</span><span style="color: #0000FF;">(</span><span style="color: #008000;">""</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"EXPAND=YES"</span><span style="color: #0000FF;">)</span>
+ <span style="color: #000000;">status</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupLabel</span><span style="color: #0000FF;">(</span><span style="color: #008000;">""</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"EXPAND=YES"</span><span style="color: #0000FF;">)</span>
+ <span style="color: #000000;">options</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupLabel</span><span style="color: #0000FF;">(</span><span style="color: #008000;">""</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"EXPAND=YES"</span><span style="color: #0000FF;">)</span>
+ <span style="color: #000000;">vbox</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupVbox</span><span style="color: #0000FF;">({</span><span style="color: #000000;">state</span><span style="color: #0000FF;">,</span><span style="color: #000000;">status</span><span style="color: #0000FF;">,</span><span style="color: #000000;">options</span><span style="color: #0000FF;">},</span><span style="color: #008000;">`MARGIN=40x40`</span><span style="color: #0000FF;">)</span>
+ <span style="color: #000000;">dlg</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupDialog</span><span style="color: #0000FF;">(</span><span style="color: #000000;">vbox</span><span style="color: #0000FF;">,</span><span style="color: #008000;">`TITLE="Finite State Machine",SIZE=200x100`</span><span style="color: #0000FF;">)</span>
+ <span style="color: #7060A8;">IupSetCallback</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"KEY_CB"</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">Icallback</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"key_cb"</span><span style="color: #0000FF;">))</span>
+ <span style="color: #000000;">transition_to</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- Ready</span>
+ <span style="color: #7060A8;">IupShow</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">)</span>
+ <span style="color: #008080;">if</span> <span style="color: #7060A8;">platform</span><span style="color: #0000FF;">()!=</span><span style="color: #004600;">JS</span> <span style="color: #008080;">then</span>
+     <span style="color: #7060A8;">IupMainLoop</span><span style="color: #0000FF;">()</span>
+     <span style="color: #7060A8;">IupHide</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">)</span>
+ <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
 <!--</lang>-->
-{{out}}
-<pre>
-Machine is READY. (D)eposit or (Q)uit :D
-(S)elect product or choose to (R)efund :S
-Dispensing product...Please (C)ollect product. :C
-Machine is READY. (D)eposit or (Q)uit :D
-(S)elect product or choose to (R)efund :R
-Please collect refund.
-Machine is READY. (D)eposit or (Q)uit :Q
-Thank you, shutting down now.
-</pre>
 =={{header|PicoLisp}}==