6 files changed, 157 insertions, 112 deletions

diff --git a/examples/listIdCatch.lua b/examples/listIdCatch.lua
deleted file mode 100644
index 5ad6f2d..0000000
--- a/examples/listIdCatch.lua
+++ /dev/null
@@ -1,28 +0,0 @@
-local m = require'lpeglabel'
-
-local terror = {}
-
-local function newError(s)
-  table.insert(terror, s)
-  return #terror
-end
-
-local errUndef = newError("undefined")
-local errId = newError("expecting an identifier")
-local errComma = newError("expecting ','")
-
-local g = m.P{
-  "S",
-  S = m.Lc(m.Lc(m.V"Id" * m.V"List", m.V"ErrId", errId),
-           m.V"ErrComma", errComma),
-  List = -m.P(1) + (m.V"Comma" + m.T(errComma)) * (m.V"Id" + m.T(errId)) * m.V"List",
-  Id = m.V"Sp" * m.R'az'^1,
-  Comma = m.V"Sp" * ",",
-  Sp = m.S" \n\t"^0,
-  ErrId = m.Cc(errId) / terror,
-  ErrComma = m.Cc(errComma) / terror
-}
-
-print(m.match(g, "one,two"))
-print(m.match(g, "one two"))
-print(m.match(g, "one,\n two,\nthree,"))
diff --git a/examples/listIdCatchRe.lua b/examples/listIdCatchRe.lua
deleted file mode 100644
index 8971191..0000000
--- a/examples/listIdCatchRe.lua
+++ /dev/null
@@ -1,34 +0,0 @@
-local re = require'relabel'
-
-local terror = {} 
-
-local function newError(l, msg) 
-  table.insert(terror, { l = l, msg = msg } )
-end
-
-newError("errId", "Error: expecting an identifier")
-newError("errComma", "Error: expecting ','")
-
-local labelCode = {}
-local labelMsg = {}
-for k, v in ipairs(terror) do 
-  labelCode[v.l] = k
-  labelMsg[v.l] = v.msg
-end
-
-re.setlabels(labelCode)
-
-local p = re.compile([[
-  S        <- Id List  /{errId}  ErrId  /{errComma}  ErrComma
-  List     <- !.  /  Comma Id List
-  Id       <- [a-z]+  /  %{errId}
-  Comma    <- ','  /  %{errComma}
-  ErrId    <- '' -> errId
-  ErrComma <- '' ->  errComma
-]], labelMsg)
-
-print(p:match("a,b"))
-print(p:match("a b"))
-print(p:match(",b"))
-
-
diff --git a/examples/recovery.lua b/examples/recovery.lua
index 3272ae7..bb17b54 100644
--- a/examples/recovery.lua
+++ b/examples/recovery.lua
@@ -1,4 +1,4 @@
-local lpeg = require"lpeglabel"
+local lpeg = require"lpeglabelrec"
 
 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
diff --git a/examples/recoveryFabio.lua b/examples/recoveryFabio.lua
new file mode 100644
index 0000000..f16c9e7
--- /dev/null
+++ b/examples/recoveryFabio.lua
@@ -0,0 +1,119 @@
+local lpeg = require"lpeglabelrec"
+
+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 T, Rec = lpeg.T, lpeg.Rec
+
+local labels = {
+  {"NoExp",     "no expression found"},
+  {"Extra",     "extra characters found after the expression"},
+  {"ExpTerm",   "expected a term after the operator"},
+  {"ExpExp",    "expected an expression after the parenthesis"},
+  {"MisClose",  "missing a closing ')' after the expression"},
+}
+
+local function labelindex(labname)
+  for i, elem in ipairs(labels) do
+    if elem[1] == labname then
+      return i
+    end
+  end
+  error("could not find label: " .. labname)
+end
+
+local errors = {}
+
+local function expect(patt, labname, recpatt)
+  local i = labelindex(labname)
+  function recorderror(input, pos)
+    table.insert(errors, {i, pos})
+    return true
+  end
+  return patt + T(i)
+end
+
+local num = R("09")^1 / tonumber
+local op = S("+-")
+
+local function compute(tokens)
+  local result = tokens[1]
+  for i = 2, #tokens, 2 do
+    if tokens[i] == '+' then
+      result = result + tokens[i+1]
+    elseif tokens[i] == '-' then
+      result = result - tokens[i+1]
+    else
+      error('unknown operation: ' .. tokens[i])
+    end
+  end
+  return result
+end
+
+local g = P {
+        "Exp",
+        Exp = Ct(V"Operand" * (C(op) * V"Operand")^0) / compute,
+        Operand = expect(V"Term", "ExpTerm"),
+        Term = num + V"Group",
+        Group = "(" *  V"InnerExp" * expect(")", "MisClose", "");
+  InnerExp = expect(V"Exp", "ExpExp", (P(1) - ")")^0 * Cc(0));
+
+}
+
+local subject, errors
+
+function recorderror(pos, lab)
+        local line, col = re.calcline(subject, pos)
+        table.insert(errors, { line = line, col = col, msg = terror[lab] })
+end
+
+function record (labname)
+        return (m.Cp() * m.Cc(labelindex(labname))) / recorderror
+end
+
+function sync (p)
+        return (-p * m.P(1))^0
+end
+
+function defaultValue ()
+        return m.Cc"NONE" 
+end
+
+local recg = P {
+        "S",
+        S = Rec(m.V"A", Cc(0), labelindex("ExpTerm")), -- default value is 0
+        A = Rec(m.V"B", Cc(0), labelindex("ExpExp")),
+        B = Rec(m.V"Sg", Cc(0), labelindex("InnerExp")),
+        Sg = Rec(g, Cc(0), labelindex("MisClose")),
+        ErrExpTerm = record(labelindex("ExpTerm")) * sync() * defaultValue()
+}
+ 
+                
+local function eval(input)
+  local result, label, suffix = recg:match(input)
+  if #errors == 0 then
+    return result
+  else
+    local out = {}
+    for i, err in ipairs(errors) do
+      local pos = err[2]
+      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
+
+print(eval "90-70*5")
+--> 20
+
+print(eval "2+")
+--> 2 + 0
+
+print(eval "-2")
+--> 0 - 2 
+
+
+print(eval "1+3+-9")
+--> 1 + 3 + 0 - 9
+
diff --git a/examples/recoveryOpFail.lua b/examples/recoveryOpFail.lua
index d65b9e0..bd1beb7 100644
--- a/examples/recoveryOpFail.lua
+++ b/examples/recoveryOpFail.lua
@@ -1,4 +1,4 @@
-local lpeg = require"lpeglabel"
+local lpeg = require"lpeglabelrec"
 
 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
diff --git a/examples/tiny.lua b/examples/tiny.lua
index 99c3144..784e031 100644
--- a/examples/tiny.lua
+++ b/examples/tiny.lua
@@ -1,4 +1,4 @@
-local re = require 'relabel'
+local re = require 'relabelrec'
 
 local terror = {}
 
@@ -25,21 +25,6 @@ newError("errFactor", "Error: expected '(', ID, or number after '*' or '/'")
 newError("errExpFac", "Error: expected expression after '('")
 newError("errClosePar", "Error: expected ')' after expression")
 
-local line
-
-local function incLine()
-        line = line + 1
-        return true
-end
-
-local function countLine(s, i)
-        line = 1
-        local p = re.compile([[
-                S <- (%nl -> incLine  / .)*
-        ]], { incLine = incLine}) 
-        p:match(s:sub(1, i))
-        return true
-end
 
 local labelCode = {}
 for k, v in ipairs(terror) do 
@@ -48,7 +33,7 @@ end
 
 re.setlabels(labelCode)
 
-local g = re.compile([[
+local g = re.compile[[
   Tiny         <- CmdSeq  
   CmdSeq       <- (Cmd (SEMICOLON / ErrSemi)) (Cmd (SEMICOLON / ErrSemi))*
   Cmd          <- IfCmd / RepeatCmd / ReadCmd / WriteCmd  / AssignCmd 
@@ -61,25 +46,24 @@ local g = re.compile([[
   SimpleExp    <- Term  ((ADD / SUB)  (Term / ErrTerm))*
   Term         <- Factor  ((MUL / DIV)  (Factor / ErrFactor))*
   Factor       <- OPENPAR  (Exp / ErrExpFac)  (CLOSEPAR / ErrClosePar)  / NUMBER  / NAME
-  ErrSemi      <- ErrCount %{errSemi}
-        ErrExpIf     <- ErrCount %{errExpIf}
-        ErrThen      <- ErrCount %{errThen}
-        ErrCmdSeq1   <- ErrCount %{errCmdSeq1}
-        ErrCmdSeq2   <- ErrCount %{errCmdSeq2}
-        ErrEnd       <- ErrCount %{errEnd}
-        ErrCmdSeqRep <- ErrCount %{errCmdSeqRep}
-        ErrUntil     <- ErrCount %{errUntil}
-        ErrExpRep    <- ErrCount %{errExpRep}
-        ErrAssignOp  <- ErrCount %{errAssignOp}
-        ErrExpAssign <- ErrCount %{errExpAssign}
-        ErrReadName  <- ErrCount %{errReadName}
-        ErrWriteExp  <- ErrCount %{errWriteExp}
-        ErrSimpExp   <- ErrCount %{errSimpExp}
-        ErrTerm      <- ErrCount %{errTerm}
-        ErrFactor    <- ErrCount %{errFactor}
-        ErrExpFac    <- ErrCount %{errExpFac}
-        ErrClosePar  <- ErrCount %{errClosePar}
-        ErrCount     <- '' => countLine 
+  ErrSemi      <- %{errSemi}
+        ErrExpIf     <- %{errExpIf}
+        ErrThen      <- %{errThen}
+        ErrCmdSeq1   <- %{errCmdSeq1}
+        ErrCmdSeq2   <- %{errCmdSeq2}
+        ErrEnd       <- %{errEnd}
+        ErrCmdSeqRep <- %{errCmdSeqRep}
+        ErrUntil     <- %{errUntil}
+        ErrExpRep    <- %{errExpRep}
+        ErrAssignOp  <- %{errAssignOp}
+        ErrExpAssign <- %{errExpAssign}
+        ErrReadName  <- %{errReadName}
+        ErrWriteExp  <- %{errWriteExp}
+        ErrSimpExp   <- %{errSimpExp}
+        ErrTerm      <- %{errTerm}
+        ErrFactor    <- %{errFactor}
+        ErrExpFac    <- %{errExpFac}
+        ErrClosePar  <- %{errClosePar}
   ADD          <- Sp '+'
   ASSIGNMENT   <- Sp ':='
   CLOSEPAR     <- Sp ')'
@@ -102,12 +86,17 @@ local g = re.compile([[
   WRITE        <- Sp 'write'
         RESERVED     <- (IF / ELSE / END / READ / REPEAT / THEN / UNTIL / WRITE) ![a-z]+
   Sp           <- %s*   
-]], { countLine = countLine })
+]]
 
 
-local function printError(n, e)
-        assert(n == nil)
-        print("Line " .. line .. ": " .. terror[e].msg)
+local function mymatch(g, s)
+        local r, e, sfail = g:match(s)
+  if not r then
+    local line, col = re.calcline(s, #s - #sfail)
+    local msg = "Error at line " .. line .. " (col " .. col .. "): "
+                return r, msg .. terror[e].msg
+        end 
+        return r
 end
 
 local s = [[
@@ -118,7 +107,7 @@ repeat
   n := n - 1
 until (n < 1);
 write f;]]
-printError(g:match(s))
+print(mymatch(g, s))
 
 s = [[
 n := 5;
@@ -128,14 +117,14 @@ repeat
   n := n - 1;
 until (n < 1);
 read ;]]
-printError(g:match(s))
+print(mymatch(g, s))
 
 s = [[
 if a < 1 then
   b := 2;
 else
   b := 3;]]
-printError(g:match(s))
+print(mymatch(g, s))
 
 s = [[
 n := 5;
@@ -145,7 +134,7 @@ repeat
   n := n - 1;
 untill (n < 1);
 ]]
-printError(g:match(s))
+print(mymatch(g, s))
 
 s = [[
 n := 5;
@@ -155,9 +144,8 @@ repeat
   n := n - 1;
 3 (n < 1);
 ]]
-printError(g:match(s))
-
-printError(g:match("a : 2"))
-printError(g:match("a := (2"))
+print(mymatch(g, s))
 
+print(mymatch(g, "a : 2"))
+print(mymatch(g, "a := (2"))