From abfa75eae1e8ac1686ddf855f08595818a25b7bc Mon Sep 17 00:00:00 2001
From: Philipp Gesang <phg@phi-gamma.net>
Date: Thu, 5 Jul 2018 21:55:54 +0200
Subject: cal: common: factor out logging

---
 common.lua | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 common.lua

(limited to 'common.lua')

diff --git a/common.lua b/common.lua
new file mode 100644
index 0000000..fe29d8c
--- /dev/null
+++ b/common.lua
@@ -0,0 +1,28 @@
+
+local verboselvl    = 0
+
+local mk_out = function (stream, threshold, newlinep)
+  local out = io.stdout
+  if stream == "err" or stream == "stderr" then out = io.stderr end
+  return function (...)
+    if verboselvl >= threshold then
+      local ok, msg = pcall (stringformat, ...)
+      if ok then
+        out:write (msg)
+        if newlinep == true then out:write "\n" end
+      ---else silently ignore
+      end
+    end
+  end
+end
+
+local set_verbosity = function (n) verboselvl = n end
+
+return
+  { println       = mk_out ("stdout", 0, true)
+  , errorln       = mk_out ("stderr", 0, true)
+  , noiseln       = mk_out ("stderr", 1, true)
+  , debugln       = mk_out ("stderr", 2, true)
+  , set_verbosity = set_verbosity
+  }
+
-- 
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