Merge pull request #14 from undecidabot/master

Adding documentation for the recovery operator

1 files changed, 8 insertions, 11 deletions

diff --git a/examples/recoveryOpFail.lua b/examples/recoveryOpFail.lua
index d65b9e0..6ddc6a2 100644
--- a/examples/recoveryOpFail.lua
+++ b/examples/recoveryOpFail.lua
@@ -1,7 +1,7 @@
 local lpeg = require"lpeglabel"
 
 local R, S, P, V = lpeg.R, lpeg.S, lpeg.P, lpeg.V
-local C, Cc, Ct, Cmt = lpeg.C, lpeg.Cc, lpeg.Ct, lpeg.Cmt
+local C, Cc, Ct, Cmt, Carg = lpeg.C, lpeg.Cc, lpeg.Ct, lpeg.Cmt, lpeg.Carg
 local T, Lc, Rec = lpeg.T, lpeg.Lc, lpeg.Rec
 
 local labels = {
@@ -21,16 +21,14 @@ local function labelindex(labname)
   error("could not find label: " .. labname)
 end
 
-local errors = {}
-
 local function expect(patt, labname, recpatt)
   local i = labelindex(labname)
-  function recorderror(input, pos)
+  local function recorderror(input, pos, errors)
     table.insert(errors, {i, pos})
     return true
   end
-        if not recpatt then recpatt = P"" end
-  return Rec(patt, Cmt("", recorderror) * recpatt)
+  if not recpatt then recpatt = P"" end
+  return Rec(patt, Cmt(Carg(1), recorderror) * recpatt)
 end
 
 local num = R("09")^1 / tonumber
@@ -57,18 +55,18 @@ end
 
 local g = P {
   "Exp",
-  Exp = Ct(V"Term" * (C(op) * V"OpRecov")^0) / compute;
-  OpRecov = V"Operand";
+  Exp = Ct(V"Term" * (C(op) * V"Operand")^0) / compute;
   Operand = expect(V"Term", "ExpTerm", Cc(0));
   Term = num + V"Group";
-  Group = "(" *  V"InnerExp" * expect(")", "MisClose", "");
+  Group = "(" *  V"InnerExp" * expect(")", "MisClose");
   InnerExp = expect(V"Exp", "ExpExp", (P(1) - ")")^0 * Cc(0));
 }
 
 g = expect(g, "NoExp", P(1)^0) * expect(-P(1), "Extra")
 
 local function eval(input)
-  local result, label, suffix = g:match(input)
+  local errors = {}
+  local result, label, suffix = g:match(input, 1, errors)
   if #errors == 0 then
     return result
   else
@@ -78,7 +76,6 @@ local function eval(input)
       local msg = labels[err[1]][2]
       table.insert(out, "syntax error: " .. msg .. " (at index " .. pos .. ")")
     end
-    errors = {}
     return nil, table.concat(out, "\n")
   end
 end