jbe@35: require "seqlua_c_example"  -- defines function "printcsv"
jbe@0: 
jbe@0: function alphabet()
jbe@0:   local letter = nil
jbe@0:   return function()
jbe@0:     if letter == nil then
jbe@0:       letter = "a"
jbe@0:     elseif letter == "z" then
jbe@0:       return nil
jbe@0:     else
jbe@0:       letter = string.char(string.byte(letter) + 1)
jbe@0:     end
jbe@0:     return letter
jbe@0:   end
jbe@0: end
jbe@0: 
jbe@35: t = {"a", "b", "c"}
jbe@35: 
jbe@35: printcsv(t)
jbe@0: -- prints:
jbe@0: -- a,b,c
jbe@0: 
jbe@0: printcsv(alphabet())
jbe@0: -- prints:
jbe@0: -- a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z
jbe@0: 
jbe@35: call_proxy = setmetatable({}, {__ipairs = function() return "call", alphabet() end})
jbe@35: 
jbe@35: printcsv(call_proxy)
jbe@35: -- prints:
jbe@35: -- a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z
jbe@35: 
jbe@35: random_access_alphabet = setmetatable({}, {
jbe@35:   __index = function(self, i)
jbe@35:     if type(i) == "number" and i >= 1 and i <= 26 then
jbe@35:       return string.char(string.byte("a") + i - 1)
jbe@35:     end
jbe@35:   end
jbe@35: })
jbe@35: 
jbe@35: printcsv(random_access_alphabet)
jbe@35: -- prints:
jbe@35: -- a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z
jbe@35: 
jbe@35: index_proxy = setmetatable({}, {
jbe@35:   __ipairs = function() return "index", random_access_alphabet end
jbe@35: })
jbe@35: 
jbe@35: printcsv(index_proxy)
jbe@35: -- prints:
jbe@35: -- a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z
jbe@35: 
jbe@35: raw_proxy = setmetatable({"dummy"}, {
jbe@35:   __ipairs = function() return "raw", t end
jbe@35: })
jbe@35: 
jbe@35: printcsv(raw_proxy)
jbe@35: -- prints:
jbe@35: -- a,b,c
jbe@35: 
jbe@35: require "seqlua"
jbe@35: 
jbe@35: do
jbe@35:   local function ipairsaux(s, i)
jbe@35:     i = i + 1
jbe@35:     if i <= s.count then
jbe@35:       return i, s.entry
jbe@35:     end
jbe@35:   end
jbe@35:   custom_proxy = setmetatable({entry = "zebra", count=5}, {
jbe@35:     __ipairs = function(self)
jbe@35:       return ipairsaux, self, 0
jbe@35:     end
jbe@35:   })
jbe@35: end
jbe@35: 
jbe@35: printcsv(custom_proxy)
jbe@35: -- prints: zebra,zebra,zebra,zebra,zebra
jbe@35: