From c5c880e5627d88ab2f7dd7596d59cf34ebba1ebb Mon Sep 17 00:00:00 2001 From: Boris Kolpackov Date: Thu, 10 Sep 2015 11:10:15 +0200 Subject: Add support for token pre-processing in lexer --- build/lexer | 14 ++++++++++++-- build/lexer.cxx | 9 +++++++++ 2 files changed, 21 insertions(+), 2 deletions(-) diff --git a/build/lexer b/build/lexer index 13f28cb..6880d39 100644 --- a/build/lexer +++ b/build/lexer @@ -40,8 +40,13 @@ namespace build class lexer: protected butl::char_scanner { public: - lexer (std::istream& is, const std::string& name) - : char_scanner (is), fail (name) {mode_.push (lexer_mode::normal);} + lexer (std::istream& is, + const std::string& name, + void (*processor) (token&, const lexer&) = nullptr) + : char_scanner (is), fail (name), processor_ (processor) + { + mode_.push (lexer_mode::normal); + } const std::string& name () const {return fail.name_;} @@ -74,6 +79,9 @@ namespace build private: token + next_impl (); + + token next_eval (); token @@ -109,6 +117,8 @@ namespace build private: fail_mark fail; + void (*processor_) (token&, const lexer&); + std::stack mode_; char pair_separator_; }; diff --git a/build/lexer.cxx b/build/lexer.cxx index b680234..79611c6 100644 --- a/build/lexer.cxx +++ b/build/lexer.cxx @@ -11,6 +11,15 @@ namespace build token lexer:: next () { + token t (next_impl ()); + if (processor_ != nullptr) + processor_ (t, *this); + return t; + } + + token lexer:: + next_impl () + { lexer_mode m (mode_.top ()); // For some modes we have dedicated imlementations of next(). -- cgit v1.1