Text based adventure game navigation

Question

I have a problem with my code. I made so much code, and now I need to place ends, which I cannot figure out how to do because I need to line everything up and then place at least 5 or 6 ends in the right places. I am fairly new to Lua and I'm sure that there's a better way to go about this, so if there is, tell me in your answer. Also, this code is unfinished.

math.randomseed(os.clock())
math.random();math.random();math.random()
local function navigate()
 print("Where would you like to go?")
 print("Somewhere peaceful(type peaceful), somewhere dangerous(type dangerous), or somewhere civilized?")
 local destination = io.read() 
 if destination == "peaceful" then
 local event = math.random(5)
 if event == 1 then
 print("You find a leafy forest.")
 print("What would you like to do? Search, Cut tree, Inventory")
 local action = io.read()
 if action == "search" then
 local searchevent = math.random(3)
 if searchevent == 1 then
 require("battle")
 elseif searchevent == 2 then
 lootdrop = math.random(5)
 if lootdrop == 1 then
 print("You found an abandoned sword. You pick it up.")
 if g_inventory1 == nil then
 g_inventory1 = "a sword"
 elseif g_inventory2 == nil then
 g_inventory2 = "a sword"
 elseif g_inventory3 == nil then
 g_inventory3 = "a sword"
 else
 print("You don't have room for this sword.Type 'leave it' or replace items. Items to replace:")
 print(g_inventory1)
 print(g_inventory2)
 print(g_inventory3)
 replace = io.read()
 if replace == g_inventory1 then
 io.write("You replaced the "); io.write(replace); io.write(" with a sword.")
 g_inventory1 = "a sword"
 elseif replace == g_inventory2 then
 io.write("You replaced the "); io.write(replace); io.write(" with a sword.")
 inventory2 = "a sword"
 elseif replace == g_inventory3 then
 io.write("You replaced the "); io.write(replace); io.write(" with a sword.")
 inventory3 = "a sword"
 elseif replace == "leave it" then
 print("You leave the sword.")
 else
 print("You randomly thought of a pointless word and moved on ahead.")
 end
 if lootdrop == 2 then
 print("A hatchet sticks out of a tree stump, and you take it out.")
 if inventory1 == nil then
 inventory1 = "a hatchet"
 elseif inventory2 == nil then
 inventory2 = "a hatchet"
 elseif inventory3 == nil then
 inventory3 = "a hatchet"
 else
 print("You don't have room for this hatchet. Replace items or 'leave it'? Items to replace:")
 print(g_inventory1)
 print(g_inventory2)
 print(g_inventory3)
 replace = io.read()
 if replace == g_inventory1 then
 io.write("You replaced the "); io.write(replace); io.write(" with the hatchet.")
 g_inventory1 = "a hatchet"
 elseif replace == g_inventory2 then
 io.write("You replaced the "); io.write(replace); io.write(" with the hatchet.")
 inventory2 = "a hatchet"
 elseif replace == g_inventory3 then
 io.write("You replaced the "); io.write(replace); io.write(" with the hatchet.")
 inventory3 = "a hatchet"
 elseif replace == "leave it" then
 print("You leave the hatchet.")
 else
 print("You randomly thought of a pointless word and moved on ahead.")
 end
 end
 if lootdrop == 3 then
 if g_inventory1 == nil then
 print("You have found a carving knife. You pick it up.")
 g_inventory1 = "a carving knife"
 elseif g_inventory2 == nil then
 print("You have found a carving knife. You pick it up.")
 g_inventory2 = "a carving knife" 
 elseif g_inventory3 == nil then
 print("You have found a carving knife. You pick it up.")
 g_inventory3 = "a carving knife"
 else
 print("You have no room for this carving knife. 'leave it' or replace an item? Items to replace:")
 print(g_inventory1)
 print(g_inventory2)
 print(g_inventory3)
 replace = io.read()
 if replace == g_inventory1 then
 io.write("You replaced the "); io.write(inventory1); io.write(" with a carving knife.")
 g_inventory1 = "a carving knife"
 elseif replace == g_inventory2 then
 io.write("You replaced the "); io.write(inventory1); io.write(" with a carving knife.")
 g_inventory2 = "a carving knife"
 elseif replace == g_inventory3 then
 io.write("You replaced the "); io.write(inventory1); io.write(" with a carving knife.")
 g_inventory3 = "a carving knife"
 elseif replace == "leave it" then
 print("You leave the sword.")
 else
 print("You think of a pointless word and move on ahead.")
 end
 if lootdrop == 4 then
 if g_inventory1 == nil then
 print("You have found a magical amulet. You pick it up.")
 g_inventory1 = "a magical amulet"
 elseif g_inventory2 == nil then
 print("You have found a magical amulet. You pick it up.")
 g_inventory2 = "a magical amulet" 
 elseif g_inventory3 == nil then
 print("You have found a carving knife. You pick it up.")
 g_inventory3 = "a magical amulet"
 else
 print("You have no room for this magical amulet. 'leave it' or replace an item? Items to replace:")
 print(g_inventory1)
 print(g_inventory2)
 print(g_inventory3)
 replace = io.read()
 if replace == g_inventory1 then
 io.write("You replaced the "); io.write(inventory1); io.write(" with a magical amulet.")
 g_inventory1 = "a magical amulet"
 elseif replace == g_inventory2 then
 io.write("You replaced the "); io.write(inventory1); io.write(" with a magical amulet.")
 g_inventory2 = "a magical amulet"
 elseif replace == g_inventory3 then
 io.write("You replaced the "); io.write(inventory1); io.write(" with a magical amulet.")
 g_inventory3 = "a magical amulet"
 elseif replace == "leave it" then
 print("You leave the amulet.")
 else
 print("You think of a pointless word and move on ahead.") 
 if lootdrop == 5 then
 print("You failed to find anything useful.")
 end
 elseif searchevent == 3 then
 print("You find nothing.")

• Dave Newton: Most important tip: code turned on its side is not a graph of how awesome it is. Pull stuff out into methods. That will start you down a better road.
• RoToRa: If you interested in text adventures you should google "interactive fiction". There is a very active community. Usually special programming languages are used, but If you want to focus on Lua, there seem to some resources for that, for example this tutorial: playwithlua.com/?p=20

Answer 1

I would separate the data from the navigation; have variables for a state. That way, as you expand your game, if you decide to change something about the interface, it's in one spot instead instead of mixed in with the data.

#!/usr/local/bin/lua
map = {
 ["peace"] = {
 title = "Peaceful",
 description = [[You find a leafy forest.]],
 exits = { danger = true },
 objects = { "tree" }
 },
 ["danger"] = {
 title = "Dangerous",
 description = [[You are on an erupting volcano with hot lava.]],
 exits = { peace = true, civil = true },
 objects = { "sword" }
 },
 ["civil"] = {
 title = "Civilized",
 description = [[You find yourself having tea in the countryside.]],
 exits = { danger = true },
 objects = { }
 }
}
objects = {
 ["tree"] = {
 name = "tree",
 description = "A tree is here.",
 take = false
 },
 ["sword"] = {
 name = "sharp sword",
 description = "A sword is here.",
 take = "You found an abandoned sword. You pick it up."
 }
}
-- these are commands that the user enters
-- they take a list of words that are generated by split()
action = {
 ["exit"] = function(words)
 where = nil
 end,
 ["go"] = function(words)
 local to = words[2]
 if(to == nil) then
 print("Go where?")
 return
 end
 if(map[where].exits[to] == true) then
 where = to
 else
 print("No exit to " .. to .. ".")
 end
 end,
 ["take"] = function(words)
 print("fixme: take has not been implemented")
 end,
 ["look"] = function(words)
 -- it refreshes the screen automatically anyway
 end
}
-- split by white space
function split(str)
 local words = {}
 local w = 1
 for s in str:gmatch("([%S]+)") do
 words[w] = s
 w = w + 1
 end
 return words
end
-- this is called in a loop; io.read is blocking for input
function navigate()
 -- describe state
 print(map[where].title .. "\n" .. map[where].description);
 for k,v in pairs(map[where].objects) do print(objects[v].description) end
 print("Exits:")
 for k,v in pairs(map[where].exits) do print(k) end
 -- input
 print("Where would you like to do?")
 local input = io.read("*line")
 local words = split(input)
 -- parse to command
 local act = action[words[1]]
 if act then
 act(words)
 else
 print("That is not a command; commands:")
 for k, v in pairs(action) do print(k) end
 end
end
-- starting state
where = "civil"
inventory = { }
-- main loop
while where do
 navigate();
 print("")
end
print("Goodbye.")

The state I used is contained in where and it's an index to the table map; when it goes nil, it exits the programme. Also inventory is a state list, but it is not used, yet. I used the tutorials at:

• https://www.lua.org/pil/11.html
• https://stackoverflow.com/questions/1426954/split-string-in-lua
• http://lua-users.org/wiki/SwitchStatement
• https://www.lua.org/pil/4.3.1.html
• https://coronalabs.com/blog/2014/09/02/tutorial-printing-table-contents/
• https://stackoverflow.com/questions/656199/search-for-an-item-in-a-lua-list