Updating the documentation and the examples

6 files changed, 139 insertions, 82 deletions

diff --git a/examples/expect.md b/examples/expect.lua
index d7d2d3e..2b7e904 100644
--- a/examples/expect.md
+++ b/examples/expect.lua
@@ -1,9 +1,3 @@
-Here's an example of an LPegLabel grammar that make its own function called
-'expect', which takes a pattern and a label as parameters and throws the label
-if the pattern fails to be matched. This function can be extended later on to
-record all errors encountered once error recovery is implemented.
-
-```lua
 local lpeg = require"lpeglabel"
 
 local R, S, P, V, C, Ct, T = lpeg.R, lpeg.S, lpeg.P, lpeg.V, lpeg.C, lpeg.Ct, lpeg.T
@@ -84,4 +78,3 @@ print(eval "1+(1-(1*2))/2x")
 
 print(eval "-1+(1-(1*2))/2")
 --> syntax error: no expression found (at index 1)
-```
diff --git a/examples/listId1.lua b/examples/listId1.lua
index 0bf26a1..12c0678 100644
--- a/examples/listId1.lua
+++ b/examples/listId1.lua
@@ -1,27 +1,38 @@
 local m = require'lpeglabel'
 
+local function calcline (s, i)
+  if i == 1 then return 1, 1 end
+  local rest, line = s:sub(1,i):gsub("[^\n]*\n", "")
+  local col = #rest
+  return 1 + line, col ~= 0 and col or 1
+end
+
 local g = m.P{
   "S",
   S = m.V"Id" * m.V"List",
-  List = -m.P(1) + ("," + m.T(2)) * m.V"Id" * m.V"List",
-  Id = m.R'az'^1 + m.T(1),
+  List = -m.P(1) + (m.V"Comma" + m.T(2)) * (m.V"Id" + m.T(1)) * m.V"List",
+  Id = m.V"Sp" * m.R'az'^1,
+  Comma = m.V"Sp" * ",",
+  Sp = m.S" \n\t"^0,
 }
 
 function mymatch (g, s)
-        local r, e, sfail = g:match(s)
-        if not r then
-                if e == 1 then
-        return r, "Error: expecting an identifier before '" .. sfail .. "'"
-        elseif e == 2 then
-        return r, "Error: expecting ',' before '" .. sfail .. "'"
-        else
-        return r, "Error"
-        end
-        end
-        return r
+  local r, e, sfail = g:match(s)
+  if not r then
+    local line, col = calcline(s, #s - #sfail)
+    local msg = "Error at line " .. line .. " (col " .. col .. ")"
+    if e == 1 then
+      return r, msg .. ": expecting an identifier before '" .. sfail .. "'"
+    elseif e == 2 then
+      return r, msg .. ": expecting ',' before '" .. sfail .. "'"
+    else
+      return r, msg
+    end
+  end
+  return r
 end
-        
-print(mymatch(g, "a,b"))
-print(mymatch(g, "a b"))
-print(mymatch(g, ", b"))
+  
+print(mymatch(g, "one,two"))
+print(mymatch(g, "one two"))
+print(mymatch(g, "one,\n two,\nthree,"))
 
diff --git a/examples/listId2.lua b/examples/listId2.lua
index 75060f9..48157f1 100644
--- a/examples/listId2.lua
+++ b/examples/listId2.lua
@@ -1,32 +1,42 @@
 local m = require'lpeglabel'
 
-local errUndef = 0
-local errId = 1
-local errComma = 2
+local terror = {}
 
-local terror = {
-        [errUndef] = "Error",
-        [errId] = "Error: expecting an identifier",
-        [errComma] = "Error: expecting ','",
-}
+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 function calcline (s, i)
+  if i == 1 then return 1, 1 end
+  local rest, line = s:sub(1,i):gsub("[^\n]*\n", "")
+  local col = #rest
+  return 1 + line, col ~= 0 and col or 1
+end
 
 local g = m.P{
   "S",
   S = m.V"Id" * m.V"List",
-  List = -m.P(1) + ("," + m.T(errComma)) * m.V"Id" * m.V"List",
-  Id = m.R'az'^1 + m.T(errId),
+  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,
 }
 
 function mymatch (g, s)
         local r, e, sfail = g:match(s)
         if not r then
-                return r, terror[e] .. " before '" .. sfail .. "'"
+                local line, col = calcline(s, #s - #sfail)
+                local msg = "Error at line " .. line .. " (col " .. col .. "): "
+                return r, msg .. terror[e] .. " before '" .. sfail .. "'"
         end
         return r
 end
         
-print(mymatch(g, "a,b"))
-print(mymatch(g, "a b"))
-print(mymatch(g, ", b"))
-
-
+print(mymatch(g, "one,two"))
+print(mymatch(g, "one two"))
+print(mymatch(g, "one,\n two,\nthree,"))
diff --git a/examples/listIdCatch.lua b/examples/listIdCatch.lua
index 38ad2e5..3cbc834 100644
--- a/examples/listIdCatch.lua
+++ b/examples/listIdCatch.lua
@@ -1,25 +1,45 @@
 local m = require'lpeglabel'
 
-local errUndef, errId, errComma = 0, 1, 2
+local terror = {}
 
-local terror = {
-  [errUndef] = "Error",
-  [errId] = "Error: expecting an identifier",
-  [errComma] = "Error: expecting ','",
-}
+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 function calcline (s, i)
+  if i == 1 then return 1, 1 end
+  local rest, line = s:sub(1,i):gsub("[^\n]*\n", "")
+  local col = #rest
+  return 1 + line, col ~= 0 and col or 1
+end
 
-g = m.P{
+local g = m.P{
   "S",
-        S = m.Lc(m.Lc(m.V"Id" * m.V"List", m.V"ErrId", errId),
+  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.V"Id" * m.V"List",
-        Id = m.R'az'^1  +  m.T(errId),
-        Comma = ","  +  m.T(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(g:match("a,b"))
-print(g:match("a b"))
-print(g:match(",b"))
+function mymatch (g, s)
+        local r, e, sfail = g:match(s)
+        if not r then
+                local line, col = calcline(s, #s - #sfail)
+                local msg = "Error at line " .. line .. " (col " .. col .. "): "
+                return r, msg .. terror[e] .. " before '" .. sfail .. "'"
+        end
+        return r
+end
 
+print(mymatch(g, "one,two"))
+print(mymatch(g, "one two"))
+print(mymatch(g, "one,\n two,\nthree,"))
diff --git a/examples/listIdRe1.lua b/examples/listIdRe1.lua
index fc213bc..361e53f 100644
--- a/examples/listIdRe1.lua
+++ b/examples/listIdRe1.lua
@@ -1,27 +1,37 @@
 local re = require 'relabel' 
 
+local function calcline (s, i)
+  if i == 1 then return 1, 1 end
+  local rest, line = s:sub(1,i):gsub("[^\n]*\n", "")
+  local col = #rest
+  return 1 + line, col ~= 0 and col or 1
+end
+
 local g = re.compile[[
-  S    <- Id List
-  List <- !.  /  (',' /         %{2}) Id List
-  Id   <- [a-z]  /  %{1}        
+  S      <- Id List
+  List   <- !.  /  (',' /       %{2}) (Id / %{1}) List
+  Id     <- Sp [a-z]+
+  Comma  <- Sp ','
+  Sp     <- %s*
 ]]
 
 function mymatch (g, s)
         local r, e, sfail = g:match(s)
         if not r then
+                local line, col = calcline(s, #s - #sfail)
+                local msg = "Error at line " .. line .. " (col " .. col .. ")"
                 if e == 1 then
-        return r, "Error: expecting an identifier before '" .. sfail .. "'" 
+        return r, msg .. ": expecting an identifier before '" .. sfail .. "'"
         elseif e == 2 then
-        return r, "Error: expecting ',' before '" .. sfail .. "'" 
+        return r, msg .. ": expecting ',' before '" .. sfail .. "'"
         else
-        return r, "Error"
+        return r, msg
         end
         end
         return r
 end
-        
-print(mymatch(g, "a,b"))
-print(mymatch(g, "a b"))
-print(mymatch(g, ", b"))
 
+print(mymatch(g, "one,two"))
+print(mymatch(g, "one two"))
+print(mymatch(g, "one,\n two,\nthree,"))
 
diff --git a/examples/listIdRe2.lua b/examples/listIdRe2.lua
index 4cd140b..ccb7ce5 100644
--- a/examples/listIdRe2.lua
+++ b/examples/listIdRe2.lua
@@ -1,35 +1,48 @@
 local re = require 'relabel' 
 
-local errUndef, errId, errComma = 0, 1, 2
-
-local terror = {
-        [errUndef] = "Error",
-        [errId] = "Error: expecting an identifier",
-        [errComma] = "Error: expecting ','",
+local errinfo = {
+        {"errUndef",  "undefined"},
+        {"errId",     "expecting an identifier"},
+        {"errComma",  "expecting ','"},
 }
 
-local tlabels = { ["errUndef"] = errUndef,
-                  ["errId"]    = errId, 
-                  ["errComma"] = errComma }
+local errmsgs = {}
+local labels = {}
+
+for i, err in ipairs(errinfo) do
+  errmsgs[i] = err[2]
+  labels[err[1]] = i
+end
+
+re.setlabels(labels)
+
+local function calcline (s, i)
+  if i == 1 then return 1, 1 end
+  local rest, line = s:sub(1,i):gsub("[^\n]*\n", "")
+  local col = #rest
+  return 1 + line, col ~= 0 and col or 1
+end
 
-re.setlabels(tlabels)
 
 local g = re.compile[[
-  S    <- Id List
-  List <- !.  /  (',' /         %{errComma}) Id List
-  Id   <- [a-z]  /  %{errId}    
+  S      <- Id List
+  List   <- !.  /  (',' /       %{errComma}) (Id / %{errId}) List
+  Id     <- Sp [a-z]+
+  Comma  <- Sp ','
+  Sp     <- %s*
 ]]
 
 function mymatch (g, s)
         local r, e, sfail = g:match(s)
         if not r then
-                return r, terror[e] .. " before '" .. sfail .. "'"
+                local line, col = calcline(s, #s - #sfail)
+                local msg = "Error at line " .. line .. " (col " .. col .. "): "
+                return r, msg .. errmsgs[e] .. " before '" .. sfail .. "'"
         end
         return r
 end
-        
-print(mymatch(g, "a,b"))
-print(mymatch(g, "a b"))
-print(mymatch(g, ", b"))
 
+print(mymatch(g, "one,two"))
+print(mymatch(g, "one two"))
+print(mymatch(g, "one,\n two,\nthree,"))