Initial commit: Pi calculation benchmark with 34 languages

- Added implementations for: bash, brainfuck, c, cpp, crystal, csharp, d, dart, elixir, erlang, fortran, go, haskell, java, javascript, julia, kotlin, objective-c, scala, typescript, lua, nim, odin, perl, php, python, r, ruby, rust, swift, zig, assembly, vimscript, wolfram
- All implementations use Machin's formula: π/4 = 4*arctan(1/5) - arctan(1/239)
- Build system with ./build.sh, test system with ./test.sh
- Performance testing with ./run_all.sh
- Comprehensive README.md explaining performance differences
- Test framework verifies correctness against known π values

lua/src/spec/pi_spec.lua

@@ -0,0 +1,59 @@
+#!/usr/bin/env lua
+-- Unit tests for Lua pi calculation using busted
+
+local SCRIPT_PATH = "/Users/einand/Code/test/lua/print_hej.lua"
+
+local function run_script(...)
+    local args = {...}
+    local cmd = "lua " .. SCRIPT_PATH
+    for _, arg in ipairs(args) do
+        cmd = cmd .. " " .. tostring(arg)
+    end
+    
+    local handle = io.popen(cmd, "r")
+    local result = handle:read("*a")
+    handle:close()
+    
+    -- Trim newline
+    result = result:gsub("\n$", "")
+    return result
+end
+
+describe("Pi calculation", function()
+    it("calculates 10 decimals", function()
+        local result = run_script(10)
+        local expected = "3.1415926535"
+        assert.are.equal(expected, result)
+    end)
+    
+    it("calculates 5 decimals", function()
+        local result = run_script(5)
+        local expected = "3.14159"
+        assert.are.equal(expected, result)
+    end)
+    
+    it("calculates 1 decimal", function()
+        local result = run_script(1)
+        local expected = "3.1"
+        assert.are.equal(expected, result)
+    end)
+    
+    it("calculates 100 decimals", function()
+        local result = run_script(100)
+        local expected = "3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679"
+        assert.are.equal(expected, result)
+    end)
+    
+    it("calculates default 100 decimals", function()
+        local result = run_script()
+        local expected = "3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679"
+        assert.are.equal(expected, result)
+    end)
+    
+    it("calculates 10000 decimals", function()
+        local result = run_script(10000)
+        -- Check length: "3." + 10000 digits = 10002 characters
+        assert.are.equal(10002, #result)
+        assert.is_true(string.sub(result, 1, 7) == "3.14159")
+    end)
+end)