fix(*) openresty coroutines

wherever coroutines are used, we now check on openresty, and if
using openresty, we fallback on the original Lua/LuaJIT coroutine
functions.

Fixes #265

.luacheckrc

@@ -2,6 +2,13 @@ unused_args     = false
 redefined       = false
 max_line_length = false
 
+globals = {
+    "ngx",
+    "coroutine._wrap",
+    "coroutine._yield",
+    "coroutine._create",
+    "coroutine._resume",
+}
 
 not_globals = {
     "string.len",

CHANGELOG.md

@@ -22,6 +22,8 @@
     [#314](https://github.com/Tieske/Penlight/pull/314)
   - Fix: `package.searchpath` (in module `pl.compat`)
     [#328](https://github.com/Tieske/Penlight/pull/328)
+  - Fix: OpenResty coroutines, used by `dir.dirtree`, `pl.lexer`, `pl.permute`. If
+    available the original coroutine functions are now used [#329](https://github.com/Tieske/Penlight/pull/329)
 
 ## 1.7.0 (2019-10-14)
 

lua/pl/dir.lua

@@ -15,10 +15,13 @@ local sub = string.sub
 local os,pcall,ipairs,pairs,require,setmetatable = os,pcall,ipairs,pairs,require,setmetatable
 local remove = os.remove
 local append = table.insert
-local wrap = coroutine.wrap
-local yield = coroutine.yield
 local assert_arg,assert_string,raise = utils.assert_arg,utils.assert_string,utils.raise
 
+-- check on OpenResty coroutine versions, and use originals if possible
+local wrap = coroutine._wrap or coroutine.wrap
+local yield = coroutine._yield or coroutine.yield
+
+
 local dir = {}
 
 local function makelist(l)

lua/pl/lexer.lua

@@ -20,11 +20,15 @@
 -- See the Guide for further @{06-data.md.Lexical_Scanning|discussion}
 -- @module pl.lexer
 
-local yield,wrap = coroutine.yield,coroutine.wrap
 local strfind = string.find
 local strsub = string.sub
 local append = table.insert
 
+-- check on OpenResty coroutine versions, and use originals if possible
+local wrap = coroutine._wrap or coroutine.wrap
+local yield = coroutine._yield or coroutine.yield
+
+
 local function assert_arg(idx,val,tp)
     if type(val) ~= tp then
         error("argument "..idx.." must be "..tp, 2)

lua/pl/permute.lua

@@ -6,10 +6,13 @@ local tablex = require 'pl.tablex'
 local utils = require 'pl.utils'
 local copy = tablex.deepcopy
 local append = table.insert
-local coroutine = coroutine
-local resume = coroutine.resume
 local assert_arg = utils.assert_arg
 
+-- check on OpenResty coroutine versions, and use originals if possible
+local co_create = coroutine._create or coroutine.create
+local co_yield = coroutine._yield or coroutine.yield
+local co_resume = coroutine._resume or coroutine.resume
+
 
 local permute = {}
 
@@ -41,9 +44,9 @@ end
 function permute.iter (a)
     assert_arg(1,a,'table')
     local n = #a
-    local co = coroutine.create(function () permgen(a, n, coroutine.yield) end)
+    local co = co_create(function () permgen(a, n, co_yield) end)
     return function ()   -- iterator
-        local _, res = resume(co)
+        local _, res = co_resume(co)
         return res
     end
 end