diff options
Diffstat (limited to 'script-beta/parser/relabel.lua')
| -rw-r--r-- | script-beta/parser/relabel.lua | 361 |
1 files changed, 361 insertions, 0 deletions
diff --git a/script-beta/parser/relabel.lua b/script-beta/parser/relabel.lua new file mode 100644 index 00000000..ac902403 --- /dev/null +++ b/script-beta/parser/relabel.lua @@ -0,0 +1,361 @@ +-- $Id: re.lua,v 1.44 2013/03/26 20:11:40 roberto Exp $ + +-- imported functions and modules +local tonumber, type, print, error = tonumber, type, print, error +local pcall = pcall +local setmetatable = setmetatable +local tinsert, concat = table.insert, table.concat +local rep = string.rep +local m = require"lpeglabel" + +-- '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 +_ENV = nil + + +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 '/'", + + 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 '{'", + + ExpNumName = "expected a number, '+', '-' or a name (no space) after '^'", + 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 a label after '{'", + + 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 function expect (pattern, label) + return pattern + m.T(label) +end + + +-- Pre-defined names +local Predef = { nl = m.P"\n" } + + +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 + -- TODO 改了一下这里的代码，重复定义不会抛错 + --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 exp = m.P{ "Exp", + Exp = S * ( m.V"Grammar" + + m.Cf(m.V"Seq" * (S * "/" * expect(S * m.V"Seq", "ExpPatt1"))^0, mt.__add) ); + 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) + + name * m.Cc"lab" + ), + "ExpNumName") + + "->" * 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) if f == "lab" then return a + mm.T(b) else return f(a,b) end 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; + 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 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 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, poserr = 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, poserr) + local err = {} + tinsert(err, "L" .. line .. ":C" .. col .. ": " .. errinfo[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 + + +-- exported names +local re = { + compile = compile, + match = match, + find = find, + gsub = gsub, + updatelocale = updatelocale, + calcline = calcline +} + +return re |