string escape sequence capture

1 files changed, 93 insertions, 0 deletions

diff --git a/include/dwu/capture b/include/dwu/capture
new file mode 100644
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--- /dev/null
+++ b/include/dwu/capture
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+// <dwu/capture> -*- C++ -*-
+// 
+// Copyright (c) 2019 Wolfgang 'datenwolf' Draxinger
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+#pragma once
+#ifndef DWU__CAPTURE__
+#define DWU__CAPTURE__ 1
+
+#include <iterator>
+
+namespace dwu {
+	template<class S>
+	S capture(S s)
+	{
+		auto it_w = s.begin();
+		for( auto it_r = s.begin()
+		   ; s.end() != it_r
+		   ; it_w = std::next(it_w)
+		){
+			if( '\\' != *it_r ){
+				*it_w = *it_r;
+				it_r = std::next(it_r);
+				continue;
+			}
+
+			it_r = std::next(it_r);
+			if( s.end() == it_r ){ break; }
+
+			int c = 0;
+			if( '0' <= *it_r && '7' >= *it_r ){
+				c = 0;
+				while( s.end() != it_r
+				    && '0' <= *it_r && '7' >= *it_r
+				){
+					c = (c<<3) | ((*it_r) - '0');
+					it_r = std::next(it_r);
+				}
+			} else
+			if( 'x' == *it_r ){
+				c = 0;
+				it_r = std::next(it_r);
+				while( s.end() != it_r ){
+					int nyb = 0;
+					if( '0' <= *it_r && '9' >= *it_r ){
+						nyb = (*it_r) - '0' + 0x0;
+					} else
+					if( 'a' <= *it_r && 'f' >= *it_r ){
+						nyb = (*it_r) - 'a' + 0xA;
+					} else
+					if( 'A' <= *it_r && 'F' >= *it_r ){
+						nyb = (*it_r) - 'A' + 0xA;
+					} else break;
+					c = (c<<4) | nyb;
+					it_r = std::next(it_r);
+				}
+			} else {
+				switch( *it_r ){
+					case 'a': c = '\a'; break;
+					case 'b': c = '\b'; break;
+					case 'f': c = '\f'; break;
+					case 'n': c = '\n'; break;
+					case 'r': c = '\r'; break;
+					case 't': c = '\t'; break;
+					case 'v': c = '\v'; break;
+					default: c = 0xFF;
+				}
+				it_r = std::next(it_r);
+			}
+			*it_w = c;
+		}
+		s.resize(it_w - s.begin());
+		return s;
+	}
+}
+
+#endif/*DWU__CAPTURE__*/