+ Penlight

1 files changed, 264 insertions, 0 deletions

diff --git a/Data/Libraries/Penlight/lua/pl/luabalanced.lua b/Data/Libraries/Penlight/lua/pl/luabalanced.lua
new file mode 100644
index 0000000..a1f7dc6
--- /dev/null
+++ b/Data/Libraries/Penlight/lua/pl/luabalanced.lua
@@ -0,0 +1,264 @@
+--- Extract delimited Lua sequences from strings.
+-- Inspired by Damian Conway's Text::Balanced in Perl. <br/>
+-- <ul>
+--   <li>[1] <a href="http://lua-users.org/wiki/LuaBalanced">Lua Wiki Page</a></li>
+--   <li>[2] http://search.cpan.org/dist/Text-Balanced/lib/Text/Balanced.pm</li>
+-- </ul> <br/>
+-- <pre class=example>
+-- local lb = require "pl.luabalanced"
+-- --Extract Lua expression starting at position 4.
+--  print(lb.match_expression("if x^2 + x > 5 then print(x) end", 4))
+--  --> x^2 + x > 5     16
+-- --Extract Lua string starting at (default) position 1.
+-- print(lb.match_string([["test\"123" .. "more"]]))
+-- --> "test\"123"     12
+-- </pre>
+-- (c) 2008, David Manura, Licensed under the same terms as Lua (MIT license).
+-- @class module
+-- @name pl.luabalanced
+
+local M = {}
+
+local assert = assert
+
+-- map opening brace <-> closing brace.
+local ends = { ['('] = ')', ['{'] = '}', ['['] = ']' }
+local begins = {}; for k,v in pairs(ends) do begins[v] = k end
+
+
+-- Match Lua string in string <s> starting at position <pos>.
+-- Returns <string>, <posnew>, where <string> is the matched
+-- string (or nil on no match) and <posnew> is the character
+-- following the match (or <pos> on no match).
+-- Supports all Lua string syntax: "...", '...', [[...]], [=[...]=], etc.
+local function match_string(s, pos)
+  pos = pos or 1
+  local posa = pos
+  local c = s:sub(pos,pos)
+  if c == '"' or c == "'" then
+    pos = pos + 1
+    while 1 do
+      pos = assert(s:find("[" .. c .. "\\]", pos), 'syntax error')
+      if s:sub(pos,pos) == c then
+        local part = s:sub(posa, pos)
+        return part, pos + 1
+      else
+        pos = pos + 2
+      end
+    end
+  else
+    local sc = s:match("^%[(=*)%[", pos)
+    if sc then
+      local _; _, pos = s:find("%]" .. sc .. "%]", pos)
+      assert(pos)
+      local part = s:sub(posa, pos)
+      return part, pos + 1
+    else
+      return nil, pos
+    end
+  end
+end
+M.match_string = match_string
+
+
+-- Match bracketed Lua expression, e.g. "(...)", "{...}", "[...]", "[[...]]",
+-- [=[...]=], etc.
+-- Function interface is similar to match_string.
+local function match_bracketed(s, pos)
+  pos = pos or 1
+  local posa = pos
+  local ca = s:sub(pos,pos)
+  if not ends[ca] then
+    return nil, pos
+  end
+  local stack = {}
+  while 1 do
+    pos = s:find('[%(%{%[%)%}%]\"\']', pos)
+    assert(pos, 'syntax error: unbalanced')
+    local c = s:sub(pos,pos)
+    if c == '"' or c == "'" then
+      local part; part, pos = match_string(s, pos)
+      assert(part)
+    elseif ends[c] then -- open
+      local mid, posb
+      if c == '[' then mid, posb = s:match('^%[(=*)%[()', pos) end
+      if mid then
+        pos = s:match('%]' .. mid .. '%]()', posb)
+        assert(pos, 'syntax error: long string not terminated')
+        if #stack == 0 then
+          local part = s:sub(posa, pos-1)
+          return part, pos
+        end
+      else
+        stack[#stack+1] = c
+        pos = pos + 1
+      end
+    else -- close
+      assert(stack[#stack] == assert(begins[c]), 'syntax error: unbalanced')
+      stack[#stack] = nil
+      if #stack == 0 then
+        local part = s:sub(posa, pos)
+        return part, pos+1
+      end
+      pos = pos + 1
+    end
+  end
+end
+M.match_bracketed = match_bracketed
+
+
+-- Match Lua comment, e.g. "--...\n", "--[[...]]", "--[=[...]=]", etc.
+-- Function interface is similar to match_string.
+local function match_comment(s, pos)
+  pos = pos or 1
+  if s:sub(pos, pos+1) ~= '--' then
+    return nil, pos
+  end
+  pos = pos + 2
+  local partt, post = match_string(s, pos)
+  if partt then
+    return '--' .. partt, post
+  end
+  local part; part, pos = s:match('^([^\n]*\n?)()', pos)
+  return '--' .. part, pos
+end
+
+
+-- Match Lua expression, e.g. "a + b * c[e]".
+-- Function interface is similar to match_string.
+local wordop = {['and']=true, ['or']=true, ['not']=true}
+local is_compare = {['>']=true, ['<']=true, ['~']=true}
+local function match_expression(s, pos)
+  pos = pos or 1
+  local _
+  local posa = pos
+  local lastident
+  local poscs, posce
+  while pos do
+    local c = s:sub(pos,pos)
+    if c == '"' or c == "'" or c == '[' and s:find('^[=%[]', pos+1) then
+      local part; part, pos = match_string(s, pos)
+      assert(part, 'syntax error')
+    elseif c == '-' and s:sub(pos+1,pos+1) == '-' then
+      -- note: handle adjacent comments in loop to properly support
+      -- backtracing (poscs/posce).
+      poscs = pos
+      while s:sub(pos,pos+1) == '--' do
+        local part; part, pos = match_comment(s, pos)
+        assert(part)
+        pos = s:match('^%s*()', pos)
+        posce = pos
+      end
+    elseif c == '(' or c == '{' or c == '[' then
+      _, pos = match_bracketed(s, pos)
+    elseif c == '=' and s:sub(pos+1,pos+1) == '=' then
+      pos = pos + 2  -- skip over two-char op containing '='
+    elseif c == '=' and is_compare[s:sub(pos-1,pos-1)] then
+      pos = pos + 1  -- skip over two-char op containing '='
+    elseif c:match'^[%)%}%];,=]' then
+      local part = s:sub(posa, pos-1)
+      return part, pos
+    elseif c:match'^[%w_]' then
+      local newident,newpos = s:match('^([%w_]+)()', pos)
+      if pos ~= posa and not wordop[newident] then -- non-first ident
+        local pose = ((posce == pos) and poscs or pos) - 1
+        while s:match('^%s', pose) do pose = pose - 1 end
+        local ce = s:sub(pose,pose)
+        if ce:match'[%)%}\'\"%]]' or
+           ce:match'[%w_]' and not wordop[lastident]
+        then
+          local part = s:sub(posa, pos-1)
+          return part, pos
+        end
+      end
+      lastident, pos = newident, newpos
+    else
+      pos = pos + 1
+    end
+    pos = s:find('[%(%{%[%)%}%]\"\';,=%w_%-]', pos)
+  end
+  local part = s:sub(posa, #s)
+  return part, #s+1
+end
+M.match_expression = match_expression
+
+
+-- Match name list (zero or more names).  E.g. "a,b,c"
+-- Function interface is similar to match_string,
+-- but returns array as match.
+local function match_namelist(s, pos)
+  pos = pos or 1
+  local list = {}
+  while 1 do
+    local c = #list == 0 and '^' or '^%s*,%s*'
+    local item, post = s:match(c .. '([%a_][%w_]*)%s*()', pos)
+    if item then pos = post else break end
+    list[#list+1] = item
+  end
+  return list, pos
+end
+M.match_namelist = match_namelist
+
+
+-- Match expression list (zero or more expressions).  E.g. "a+b,b*c".
+-- Function interface is similar to match_string,
+-- but returns array as match.
+local function match_explist(s, pos)
+  pos = pos or 1
+  local list = {}
+  while 1 do
+    if #list ~= 0 then
+      local post = s:match('^%s*,%s*()', pos)
+      if post then pos = post else break end
+    end
+    local item; item, pos = match_expression(s, pos)
+    assert(item, 'syntax error')
+    list[#list+1] = item
+  end
+  return list, pos
+end
+M.match_explist = match_explist
+
+
+-- Replace snippets of code in Lua code string <s>
+-- using replacement function f(u,sin) --> sout.
+-- <u> is the type of snippet ('c' = comment, 's' = string,
+-- 'e' = any other code).
+-- Snippet is replaced with <sout> (unless <sout> is nil or false, in
+-- which case the original snippet is kept)
+-- This is somewhat analogous to string.gsub .
+local function gsub(s, f)
+  local pos = 1
+  local posa = 1
+  local sret = ''
+  while 1 do
+    pos = s:find('[%-\'\"%[]', pos)
+    if not pos then break end
+    if s:match('^%-%-', pos) then
+      local exp = s:sub(posa, pos-1)
+      if #exp > 0 then sret = sret .. (f('e', exp) or exp) end
+      local comment; comment, pos = match_comment(s, pos)
+      sret = sret .. (f('c', assert(comment)) or comment)
+      posa = pos
+    else
+      local posb = s:find('^[\'\"%[]', pos)
+      local str
+      if posb then str, pos = match_string(s, posb) end
+      if str then
+        local exp = s:sub(posa, posb-1)
+        if #exp > 0 then sret = sret .. (f('e', exp) or exp) end
+        sret = sret .. (f('s', str) or str)
+        posa = pos
+      else
+        pos = pos + 1
+      end
+    end
+  end
+  local exp = s:sub(posa)
+  if #exp > 0 then sret = sret .. (f('e', exp) or exp) end
+  return sret
+end
+M.gsub = gsub
+
+
+return M