1 files changed, 56 insertions, 35 deletions

@@ -1,40 +1,47 @@
 --- lam.environment
 
 local util = require "util"
-local types = require("types")
-
-if not table.unpack then table.unpack = unpack end
+local types = require "types"
+table.unpack = table.unpack or unpack
 
 local global = {
-        -- constants
+        -- constants ---- TODO this should be at the reader level
         ["#t"] = true,
         ["#f"] = false,
 }
 
 --- Types ---
 
-for name, func in pairs(types) do
-        if name == "lamtype" then
-                global.type = func
-        else
-                global[name] = func
-        end
-end
+global.luatype = type
+global.type = types.lamtype
+
+global["number?"] = function (x) types.isa(x, "Number") end
+global["string?"] = function (x) types.isa(x, "String") end
+global["symbol?"] = function (x) types.isa(x, "Symbol") end
+global["pair?"] = function (x) types.isa(x, "Pair") end
+global["is-a?"] = function (x, t) types.isa(x, t) end
 
 --- Basic functions ---
 
-global.begin = function(...)
-        local xs = {...}
-        return xs[#xs]
-end
+global.car = function (pair) return pair[1] end
+global.cdr = function (pair) return pair[2] end
 
-global.car = util.car
-global.cdr = util.cdr
+-- global.list = types.List
 
-global.list = function(...) return {...} end
+global["list?"] =
+        function (x)
+                -- TODO : detect circular lists
+                if type(x) == "table" then
+                        if #x == 0 then return true end
+                        if type(x[2]) ~= "table" then return false end
+                end
+                return global["list?"](x[2])
+        end
 
---- Higher-order functions ---
+global["null?"] = function (x) return type(x) == "table" and #x == 0 end
 
+--- Higher-order functions ---
+--[[
 global.apply = function(fn, ...)
         local args = {...}
         local last = args[#args]
@@ -49,7 +56,7 @@ end
 global.map = function(fn, list)
         return util.map(fn, list)
 end
-
+--]]
 --- Math ---
 -- NOTE: we do not have the full numeric tower yet!
 
@@ -57,7 +64,15 @@ for name, func in pairs(math) do
         global[name] = func
 end
 
-global["+"] = function (...)
+global.fold =
+        function (fn, lis)
+                local out = {}
+
+                return types.List(out)
+        end
+
+global["+"] = function (lis)
+        return
         return util.reduce({...}, 0, function (a, b) return a + b end)
 end
 
@@ -102,40 +117,46 @@ global["/"] = function (...)
         end
 end
 
-global["="] = function (...)
-        for _, v in ipairs({...}) do
-                if not a == b then return false end
+--[[
+global["="] =
+        function (...)
+                for _, v in ipairs({...}) do
+                        if not a == b then return false end
+                end
+                return true
         end
-        return true
-end
 
-global["<"] = function (...)
-        for _, v in ipairs({...}) do
-                if not a < b then return false end
+global["<"] =
+        function (...)
+                for _, v in ipairs({...}) do
+                        if not a < b then return false end
+                end
+                return true
         end
-        return true
-end
 
-global["<="] = function (...)
+global["<="] =
+        function (...)
         for _, v in ipairs({...}) do
                 if not a <= b then return false end
         end
         return true
 end
 
-global[">"] = function (...)
+global[">"] =
+        function (...)
         for _, v in ipairs({...}) do
                 if not a > b then return false end
         end
         return true
 end
 
-global[">="] = function (...)
+global[">="] =
+        function (...)
         for _, v in ipairs({...}) do
                 if not a >= b then return false end
         end
         return true
 end
-
+--]]
 ---
 return global