1 files changed, 396 insertions, 0 deletions

diff --git a/relabelrec.lua b/relabelrec.lua
new file mode 100644
index 0000000..16ca7f0
--- /dev/null
+++ b/relabelrec.lua
@@ -0,0 +1,396 @@
+-- $Id: re.lua,v 1.44 2013/03/26 20:11:40 roberto Exp $
+
+-- imported functions and modules
+local tonumber, type, print, error, ipairs = tonumber, type, print, error, ipairs
+local pcall = pcall
+local setmetatable = setmetatable
+local unpack, tinsert, concat = table.unpack or unpack, table.insert, table.concat
+local rep = string.rep
+local m = require"lpeglabelrec"
+
+-- 'm' will be used to parse expressions, and 'mm' will be used to
+-- create expressions; that is, 're' runs on 'm', creating patterns
+-- on 'mm'
+local mm = m
+
+-- pattern's metatable
+local mt = getmetatable(mm.P(0))
+
+
+
+-- No more global accesses after this point
+local version = _VERSION
+if version == "Lua 5.2" then _ENV = nil end
+
+
+local any = m.P(1)
+local dummy = mm.P(false)
+
+
+local errinfo = {
+  {"NoPatt", "no pattern found"},
+  {"ExtraChars", "unexpected characters after the pattern"},
+
+  {"ExpPatt1", "expected a pattern after '/' or the label(s)"},
+
+  {"ExpPatt2", "expected a pattern after '&'"},
+  {"ExpPatt3", "expected a pattern after '!'"},
+
+  {"ExpPatt4", "expected a pattern after '('"},
+  {"ExpPatt5", "expected a pattern after ':'"},
+  {"ExpPatt6", "expected a pattern after '{~'"},
+  {"ExpPatt7", "expected a pattern after '{|'"},
+
+  {"ExpPatt8", "expected a pattern after '<-'"},
+
+  {"ExpPattOrClose", "expected a pattern or closing '}' after '{'"},
+
+  {"ExpNum", "expected a number after '^', '+' or '-' (no space)"},
+  {"ExpCap", "expected a string, number, '{}' or name after '->'"},
+
+  {"ExpName1", "expected the name of a rule after '=>'"},
+  {"ExpName2", "expected the name of a rule after '=' (no space)"},
+  {"ExpName3", "expected the name of a rule after '<' (no space)"},
+
+  {"ExpLab1", "expected at least one label after '{'"},
+  {"ExpLab2", "expected a label after the comma"},
+
+  {"ExpNameOrLab", "expected a name or label after '%' (no space)"},
+
+  {"ExpItem", "expected at least one item after '[' or '^'"},
+
+  {"MisClose1", "missing closing ')'"},
+  {"MisClose2", "missing closing ':}'"},
+  {"MisClose3", "missing closing '~}'"},
+  {"MisClose4", "missing closing '|}'"},
+  {"MisClose5", "missing closing '}'"},  -- for the captures
+
+  {"MisClose6", "missing closing '>'"},
+  {"MisClose7", "missing closing '}'"},  -- for the labels
+
+  {"MisClose8", "missing closing ']'"},
+
+  {"MisTerm1", "missing terminating single quote"},
+  {"MisTerm2", "missing terminating double quote"},
+}
+
+local errmsgs = {}
+local labels = {}
+
+for i, err in ipairs(errinfo) do
+  errmsgs[i] = err[2]
+  labels[err[1]] = i
+end
+
+local function expect (pattern, labelname)
+  local label = labels[labelname]
+  return pattern + m.T(label)
+end
+
+
+-- Pre-defined names
+local Predef = { nl = m.P"\n" }
+local tlabels = {}
+
+
+local mem
+local fmem
+local gmem
+
+
+local function updatelocale ()
+  mm.locale(Predef)
+  Predef.a = Predef.alpha
+  Predef.c = Predef.cntrl
+  Predef.d = Predef.digit
+  Predef.g = Predef.graph
+  Predef.l = Predef.lower
+  Predef.p = Predef.punct
+  Predef.s = Predef.space
+  Predef.u = Predef.upper
+  Predef.w = Predef.alnum
+  Predef.x = Predef.xdigit
+  Predef.A = any - Predef.a
+  Predef.C = any - Predef.c
+  Predef.D = any - Predef.d
+  Predef.G = any - Predef.g
+  Predef.L = any - Predef.l
+  Predef.P = any - Predef.p
+  Predef.S = any - Predef.s
+  Predef.U = any - Predef.u
+  Predef.W = any - Predef.w
+  Predef.X = any - Predef.x
+  mem = {}    -- restart memoization
+  fmem = {}
+  gmem = {}
+  local mt = {__mode = "v"}
+  setmetatable(mem, mt)
+  setmetatable(fmem, mt)
+  setmetatable(gmem, mt)
+end
+
+
+updatelocale()
+
+
+
+local I = m.P(function (s,i) print(i, s:sub(1, i-1)); return i end)
+
+
+local function getdef (id, defs)
+  local c = defs and defs[id]
+  if not c then
+    error("undefined name: " .. id)
+  end
+  return c
+end
+
+
+local function mult (p, n)
+  local np = mm.P(true)
+  while n >= 1 do
+    if n%2 >= 1 then np = np * p end
+    p = p * p
+    n = n/2
+  end
+  return np
+end
+
+local function equalcap (s, i, c)
+  if type(c) ~= "string" then return nil end
+  local e = #c + i
+  if s:sub(i, e - 1) == c then return e else return nil end
+end
+
+
+local S = (Predef.space + "--" * (any - Predef.nl)^0)^0
+
+local name = m.C(m.R("AZ", "az", "__") * m.R("AZ", "az", "__", "09")^0)
+
+local arrow = S * "<-"
+
+-- a defined name only have meaning in a given environment
+local Def = name * m.Carg(1)
+
+local num = m.C(m.R"09"^1) * S / tonumber
+
+local String = "'" * m.C((any - "'" - m.P"\n")^0) * expect("'", "MisTerm1")
+             + '"' * m.C((any - '"' - m.P"\n")^0) * expect('"', "MisTerm2")
+
+
+local defined = "%" * Def / function (c,Defs)
+  local cat =  Defs and Defs[c] or Predef[c]
+  if not cat then
+    error("name '" .. c .. "' undefined")
+  end
+  return cat
+end
+
+local Range = m.Cs(any * (m.P"-"/"") * (any - "]")) / mm.R
+
+local item = defined + Range + m.C(any - m.P"\n")
+
+local Class =
+    "["
+  * (m.C(m.P"^"^-1))    -- optional complement symbol
+  * m.Cf(expect(item, "ExpItem") * (item - "]")^0, mt.__add)
+    / function (c, p) return c == "^" and any - p or p end
+  * expect("]", "MisClose8")
+
+local function adddef (t, k, exp)
+  if t[k] then
+    error("'"..k.."' already defined as a rule")
+  else
+    t[k] = exp
+  end
+  return t
+end
+
+local function firstdef (n, r) return adddef({n}, n, r) end
+
+
+local function NT (n, b)
+  if not b then
+    error("rule '"..n.."' used outside a grammar")
+  else return mm.V(n)
+  end
+end
+
+local function choicerec (...)
+  local t = { ... }
+  local n = #t
+  local p = t[1]
+  local i = 2
+  while i + 1 <= n do
+    -- t[i] == nil when there are no labels
+    p = t[i] and mm.Rec(p, t[i+1], unpack(t[i])) or mt.__add(p, t[i+1])
+    i = i + 2
+  end
+
+  return p
+end
+
+local exp = m.P{ "Exp",
+  Exp = S * ( m.V"Grammar"
+            + (m.V"Seq" * (S * (("//" * m.Ct(m.V"Labels")) + ("/" * m.Cc(nil)))
+                                   * expect(S * m.V"Seq", "ExpPatt1")
+                            )^0
+              ) / choicerec);
+  Labels = m.P"{" * expect(S * m.V"Label", "ExpLab1")
+           * (S * "," * expect(S * m.V"Label", "ExpLab2"))^0
+           * expect(S * "}", "MisClose7");
+  Seq = m.Cf(m.Cc(m.P"") * m.V"Prefix" * (S * m.V"Prefix")^0, mt.__mul);
+  Prefix = "&" * expect(S * m.V"Prefix", "ExpPatt2") / mt.__len
+         + "!" * expect(S * m.V"Prefix", "ExpPatt3") / mt.__unm
+         + m.V"Suffix";
+  Suffix = m.Cf(m.V"Primary" *
+          ( S * ( m.P"+" * m.Cc(1, mt.__pow)
+                + m.P"*" * m.Cc(0, mt.__pow)
+                + m.P"?" * m.Cc(-1, mt.__pow)
+                + "^" * expect( m.Cg(num * m.Cc(mult))
+                              + m.Cg(m.C(m.S"+-" * m.R"09"^1) * m.Cc(mt.__pow)
+                              ),
+                          "ExpNum")
+                + "->" * expect(S * ( m.Cg((String + num) * m.Cc(mt.__div))
+                                    + m.P"{}" * m.Cc(nil, m.Ct)
+                                    + m.Cg(Def / getdef * m.Cc(mt.__div))
+                                    ),
+                           "ExpCap")
+                + "=>" * expect(S * m.Cg(Def / getdef * m.Cc(m.Cmt)),
+                           "ExpName1")
+                )
+          )^0, function (a,b,f) return f(a,b) end );
+  Primary = "(" * expect(m.V"Exp", "ExpPatt4") * expect(S * ")", "MisClose1")
+          + String / mm.P
+          + Class
+          + defined
+          + "%" * expect(m.P"{", "ExpNameOrLab")
+            * expect(S * m.V"Label", "ExpLab1")
+            * expect(S * "}", "MisClose7") / mm.T
+          + "{:" * (name * ":" + m.Cc(nil)) * expect(m.V"Exp", "ExpPatt5")
+            * expect(S * ":}", "MisClose2")
+            / function (n, p) return mm.Cg(p, n) end
+          + "=" * expect(name, "ExpName2")
+            / function (n) return mm.Cmt(mm.Cb(n), equalcap) end
+          + m.P"{}" / mm.Cp
+          + "{~" * expect(m.V"Exp", "ExpPatt6")
+            * expect(S * "~}", "MisClose3") / mm.Cs
+          + "{|" * expect(m.V"Exp", "ExpPatt7")
+            * expect(S * "|}", "MisClose4") / mm.Ct
+          + "{" * expect(m.V"Exp", "ExpPattOrClose")
+            * expect(S * "}", "MisClose5") / mm.C
+          + m.P"." * m.Cc(any)
+          + (name * -arrow + "<" * expect(name, "ExpName3")
+             * expect(">", "MisClose6")) * m.Cb("G") / NT;
+  Label = num + name / function (f) return tlabels[f] end;
+  Definition = name * arrow * expect(m.V"Exp", "ExpPatt8");
+  Grammar = m.Cg(m.Cc(true), "G")
+            * m.Cf(m.V"Definition" / firstdef * (S * m.Cg(m.V"Definition"))^0,
+                adddef) / mm.P;
+}
+
+local pattern = S * m.Cg(m.Cc(false), "G") * expect(exp, "NoPatt") / mm.P
+                * S * expect(-any, "ExtraChars")
+
+local function lineno (s, i)
+  if i == 1 then return 1, 1 end
+  local adjustment = 0
+  -- report the current line if at end of line, not the next
+  if s:sub(i,i) == '\n' then
+    i = i-1
+    adjustment = 1
+  end
+  local rest, num = s:sub(1,i):gsub("[^\n]*\n", "")
+  local r = #rest
+  return 1 + num, (r ~= 0 and r or 1) + adjustment
+end
+
+local function splitlines(str)
+  local t = {}
+  local function helper(line) tinsert(t, line) return "" end
+  helper((str:gsub("(.-)\r?\n", helper)))
+  return t
+end
+
+local function compile (p, defs)
+  if mm.type(p) == "pattern" then return p end   -- already compiled
+  p = p .. " " -- for better reporting of column numbers in errors when at EOF
+  local ok, cp, label, suffix = pcall(function() return pattern:match(p, 1, defs) end)
+  if not ok and cp then
+    if type(cp) == "string" then
+      cp = cp:gsub("^[^:]+:[^:]+: ", "")
+    end
+    error(cp, 3)
+  end
+  if not cp then
+    local lines = splitlines(p)
+    local line, col = lineno(p, #p - #suffix + 1)
+    local err = {}
+    tinsert(err, "L" .. line .. ":C" .. col .. ": " .. errmsgs[label])
+    tinsert(err, lines[line])
+    tinsert(err, rep(" ", col-1) .. "^")
+    error("syntax error(s) in pattern\n" .. concat(err, "\n"), 3)
+  end
+  return cp
+end
+
+local function match (s, p, i)
+  local cp = mem[p]
+  if not cp then
+    cp = compile(p)
+    mem[p] = cp
+  end
+  return cp:match(s, i or 1)
+end
+
+local function find (s, p, i)
+  local cp = fmem[p]
+  if not cp then
+    cp = compile(p) / 0
+    cp = mm.P{ mm.Cp() * cp * mm.Cp() + 1 * mm.V(1) }
+    fmem[p] = cp
+  end
+  local i, e = cp:match(s, i or 1)
+  if i then return i, e - 1
+  else return i
+  end
+end
+
+local function gsub (s, p, rep)
+  local g = gmem[p] or {}   -- ensure gmem[p] is not collected while here
+  gmem[p] = g
+  local cp = g[rep]
+  if not cp then
+    cp = compile(p)
+    cp = mm.Cs((cp / rep + 1)^0)
+    g[rep] = cp
+  end
+  return cp:match(s)
+end
+
+local function setlabels (t)
+  tlabels = t
+end
+
+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
+
+
+-- exported names
+local re = {
+  compile = compile,
+  match = match,
+  find = find,
+  gsub = gsub,
+  updatelocale = updatelocale,
+  setlabels = setlabels,
+        calcline = calcline
+}
+
+if version == "Lua 5.1" then _G.re = re end
+
+return re