362 lines
9.7 KiB
Lua
362 lines
9.7 KiB
Lua
-- $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
|