y.output から文法情報のみを抽出

yacc-grammar-extractor.cpp

#include <cctype>
#include <iostream>
#include <fstream>
#include <string>
#include <regex>
#include <unordered_map>

auto main() -> int
{
    while (true) {
        std::string buffer;
        std::getline(std::cin, buffer);
        if (buffer.find("Grammar") != std::string::npos) {
            break;
        }
    }
    std::string current;
    std::unordered_map<std::string, std::vector<std::string>> data;
    while (true) {
        std::string buffer;
        std::getline(std::cin, buffer);
        if (buffer == "") {
            continue;
        }
        if (!std::isspace(buffer[0])) {
            break;
        }
        std::smatch matches;
        if (std::regex_search(buffer, matches, std::regex("^\\s*\\d+\\s*([$@\\w]+):\\s*(.*)"))) {
            if (matches[1].str()[0] == '@') {
                continue;
            } else {
                current = matches[1].str();
                data[matches[1].str()].push_back(matches[2].str());
                continue;
            }
        }
        if (std::regex_search(buffer, matches, std::regex("^\\s*\\d+\\s*\\|\\s*(.*)"))) {
            data[current].push_back(matches[1].str());
            continue;
        }
    }
    for (decltype(auto) entry: data) {
        int indent = entry.first.size();
        std::cout << entry.first << ": ";
        for (int i = 0; i < entry.second.size(); ++i) {
            std::string second = std::regex_replace(entry.second[i], std::regex("@\\d+"), "");
            if (i == 0) {
                std::cout << second << std::endl;
            } else {
                std::cout << std::string(indent, ' ') << "| " << second << std::endl;
            }
        }
    }
    return 0;
}

yacc-grammar-extractor.lua

while true do
  local buf = io.read()
  if buf:find("Grammar") or buf:find("文法") then
    break
  end
end

local currentLabel
local data = {}
local order = {}
local maxindent = 0
while true do
  local buf = io.read()
  if buf == "" then
    goto CONTINUE
  elseif not buf:sub(1, 1):match("^%s") then
    break
  end

  local label, member = buf:match("^%s*%d+%s*([$%w]+):%s*(.*)")
  if label then
    if label:len() > maxindent then
      maxindent = label:len()
    end
    currentLabel = label
    if not data[label] then
      table.insert(order, label)
      data[label] = {}
    end
    table.insert(data[label], member)
    goto CONTINUE
  end
  member = buf:match("^%s*%d+%s*|%s*(.*)")
  if member then
    table.insert(data[currentLabel], member)
    goto CONTINUE
  end
  ::CONTINUE::
end

for _, label in ipairs(order) do
  local members = data[label]
  io.write(("%s"):format(label))
  for i, member in ipairs(members) do
    member = member:gsub("$@%d+ ", "")
    member = member:gsub("@%d+ ", "")
    if i == 1 then
      io.write((" "):rep(maxindent - ("%s: "):format(label):len() + 2))
      io.write((": %s\n"):format(member))
    else
      io.write((" "):rep(maxindent))
      io.write(("| %s\n"):format(member))
    end
  end
end

yacc-grammar-extractor.md

Lua

使い方

cat y.output | lua yacc-grammar-extractor.lua

C++

コンパイル

g++ -o yacc-grammar-extractor yacc-grammar-extractor.cpp -std=c++1y

使い方

---

cat y.output | ./yacc-grammar-extractor

利用例

Lua 1.1 の YACC ファイル lua.stx の y.output を以下コマンドで生成.

yacc -v lua.sty

生成された y.output から文法情報のみ抽出.

cat y.output | lua yacc-grammar-extractor.lua

以下のような出力が得られる.

exprlist: /* empty */
        | exprlist1
statlist: /* empty */
        | statlist stat sc
decinit: /* empty */
       | '=' exprlist1
ffieldlist1: ffield
           | ffieldlist1 ',' ffield
expr1: expr
var: NAME
   | var  '[' expr1 ']'
   | var  '.' NAME
function: FUNCTION NAME  '(' parlist ')'  block END
ffieldlist: /* empty */
          | ffieldlist1
lfieldlist1: expr1
           | lfieldlist1 ',' expr1
localdeclist: NAME
            | localdeclist ',' NAME
expr: '(' expr ')'
    | expr1 '=' expr1
    | expr1 '<' expr1
    | expr1 '>' expr1
    | expr1 NE expr1
    | expr1 LE expr1
    | expr1 GE expr1
    | expr1 '+' expr1
    | expr1 '-' expr1
    | expr1 '*' expr1
    | expr1 '/' expr1
    | expr1 CONC expr1
    | '+' expr1
    | '-' expr1
    | typeconstructor
    | '@' '(' dimension ')'
    | var
    | NUMBER
    | STRING
    | NIL
    | functioncall
    | NOT expr1
    | expr1 AND PrepJump  expr1
    | expr1 OR PrepJump  expr1
typeconstructor: '@'  objectname fieldlist
PrepJump: /* empty */
objectname: /* empty */
          | NAME
varlist1: var
        | varlist1 ',' var
$accept: functionlist $end
exprlist1: expr
         | exprlist1 ','  expr
block:  statlist  ret
parlist: /* empty */
       | parlist1
parlist1: NAME
        | parlist1 ',' NAME
stat1: IF expr1 THEN PrepJump block PrepJump elsepart END
     | WHILE  expr1 DO PrepJump block PrepJump END
     | REPEAT  block UNTIL expr1 PrepJump
     | varlist1 '=' exprlist1
     | functioncall
     | typeconstructor
     | LOCAL localdeclist decinit
dimension: /* empty */
         | expr1
ffield: NAME  '=' expr1
sc: /* empty */
  | ';'
stat:  stat1
functionvalue: var
ret: /* empty */
   |  RETURN exprlist sc
elsepart: /* empty */
        | ELSE block
        | ELSEIF expr1 THEN PrepJump block PrepJump elsepart
setdebug: DEBUG
functionlist: /* empty */
            | functionlist  stat sc
            | functionlist function
            | functionlist setdebug
functioncall: functionvalue  '(' exprlist ')'
lfieldlist: /* empty */
          | lfieldlist1
fieldlist: '{' ffieldlist '}'
         | '[' lfieldlist ']'