diff options
| -rw-r--r-- | libbutl/char-scanner.cxx | 6 | ||||
| -rw-r--r-- | libbutl/char-scanner.ixx | 23 | ||||
| -rw-r--r-- | libbutl/char-scanner.mxx | 40 |
3 files changed, 61 insertions, 8 deletions
diff --git a/libbutl/char-scanner.cxx b/libbutl/char-scanner.cxx index 2e680b6..607d887 100644 --- a/libbutl/char-scanner.cxx +++ b/libbutl/char-scanner.cxx @@ -35,8 +35,10 @@ using namespace std; namespace butl { char_scanner:: - char_scanner (istream& is, bool crlf) - : is_ (is), + char_scanner (istream& is, bool crlf, uint64_t l) + : line (l), + column (1), + is_ (is), buf_ (dynamic_cast<fdbuf*> (is.rdbuf ())), gptr_ (nullptr), egptr_ (nullptr), diff --git a/libbutl/char-scanner.ixx b/libbutl/char-scanner.ixx index 0e00dfd..c32b034 100644 --- a/libbutl/char-scanner.ixx +++ b/libbutl/char-scanner.ixx @@ -52,12 +52,31 @@ namespace butl inline void char_scanner:: get_ () { + int_type c; + if (gptr_ != egptr_) { buf_->gbump (1); - ++gptr_; + c = *gptr_++; } else - is_.get (); // About as fast as ignore() and way faster than tellg(). + c = is_.get (); // About as fast as ignore() and way faster than tellg(). + + if (save_ != nullptr && c != xchar::traits_type::eof ()) + save_->push_back (static_cast<char_type> (c)); + } + + inline void char_scanner:: + save_start (std::string& b) + { + assert (save_ == nullptr); + save_ = &b; + } + + inline void char_scanner:: + save_stop () + { + assert (save_ != nullptr); + save_ = nullptr; } } diff --git a/libbutl/char-scanner.mxx b/libbutl/char-scanner.mxx index af4dad9..9bfdeec 100644 --- a/libbutl/char-scanner.mxx +++ b/libbutl/char-scanner.mxx @@ -6,7 +6,7 @@ #pragma once #endif -// C includes. +#include <cassert> #ifndef __cpp_lib_modules #include <string> // char_traits @@ -45,7 +45,10 @@ LIBBUTL_MODEXPORT namespace butl // a number of optimizations that assume nobody else is messing with the // stream. // - char_scanner (std::istream& is, bool crlf = true); + // The line argument can be used to override the start line in the stream + // (useful when re-scanning data saved with the save_* facility). + // + char_scanner (std::istream& is, bool crlf = true, std::uint64_t line = 1); char_scanner (const char_scanner&) = delete; char_scanner& operator= (const char_scanner&) = delete; @@ -107,8 +110,32 @@ LIBBUTL_MODEXPORT namespace butl // Line and column of the next character to be extracted from the stream // by peek() or get(). // - std::uint64_t line = 1; - std::uint64_t column = 1; + std::uint64_t line; + std::uint64_t column; + + // Ability to save raw data as it is being scanned. Note that the + // character is only saved when it is got, not peeked. + // + public: + void + save_start (std::string&); + + void + save_stop (); + + struct save_guard + { + explicit + save_guard (char_scanner& s, std::string& b): s_ (&s) {s.save_start (b);} + + void + stop () {if (s_ != nullptr) {s_->save_stop (); s_ = nullptr;}} + + ~save_guard () {stop ();} + + private: + char_scanner* s_; + }; protected: using int_type = xchar::int_type; @@ -123,10 +150,15 @@ LIBBUTL_MODEXPORT namespace butl protected: std::istream& is_; + // Note that if you are reading from the buffer directly, then it is + // also your responsibility to save the data. + // fdbuf* buf_; // NULL if not ifdstream. const char_type* gptr_; const char_type* egptr_; + std::string* save_ = nullptr; + bool crlf_; bool eos_ = false; |