initial commit, 4.5 stable

thirdparty/embree/common/lexers/stream.h

@@ -0,0 +1,215 @@
+// Copyright 2009-2021 Intel Corporation
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+
+#include "../sys/platform.h"
+#include "../sys/ref.h"
+#include "../sys/filename.h"
+#include "../sys/estring.h"
+
+#include <vector>
+#include <iostream>
+#include <cstdio>
+#include <string.h>
+
+namespace embree
+{
+  /*! stores the location of a stream element in the source */
+  class ParseLocation
+  {
+  public:
+    ParseLocation () : lineNumber(-1), colNumber(-1) {}
+    ParseLocation (std::shared_ptr<std::string> fileName, ssize_t lineNumber, ssize_t colNumber, ssize_t /*charNumber*/)
+      : fileName(fileName), lineNumber(lineNumber), colNumber(colNumber) {}
+
+    std::string str() const
+    {
+      std::string str = "unknown";
+      if (fileName) str = *fileName;
+      if (lineNumber >= 0) str += " line " + toString(lineNumber);
+      if (lineNumber >= 0 && colNumber >= 0) str += " character " + toString(colNumber);
+      return str;
+    }
+
+  private:
+    std::shared_ptr<std::string> fileName;         /// name of the file (or stream) the token is from
+    ssize_t lineNumber;           /// the line number the token is from
+    ssize_t colNumber;            /// the character number in the current line
+  };
+
+  /*! a stream class templated over the stream elements */
+  template<typename T> class Stream : public RefCount
+  {
+    enum { BUF_SIZE = 1024 };
+    
+  private:
+    virtual T next() = 0;
+    virtual ParseLocation location() = 0;
+    __forceinline std::pair<T,ParseLocation> nextHelper() {
+      ParseLocation l = location();
+      T v = next();
+      return std::pair<T,ParseLocation>(v,l);
+    }
+    __forceinline void push_back(const std::pair<T,ParseLocation>& v) {
+      if (past+future == BUF_SIZE) pop_front();
+      size_t end = (start+past+future++)%BUF_SIZE;
+      buffer[end] = v;
+    }
+    __forceinline void pop_front() {
+      if (past == 0) THROW_RUNTIME_ERROR("stream buffer empty");
+      start = (start+1)%BUF_SIZE; past--;
+    }
+  public:
+    Stream () : start(0), past(0), future(0), buffer(BUF_SIZE) {}
+    virtual ~Stream() {}
+    
+  public:
+    
+    const ParseLocation& loc() {
+      if (future == 0) push_back(nextHelper());
+      return buffer[(start+past)%BUF_SIZE].second;
+    }
+    T get() {
+      if (future == 0) push_back(nextHelper());
+      T t = buffer[(start+past)%BUF_SIZE].first;
+      past++; future--;
+      return t;
+    }
+    const T& peek() {
+      if (future == 0) push_back(nextHelper());
+      return buffer[(start+past)%BUF_SIZE].first;
+    }
+    const T& unget(size_t n = 1) {
+      if (past < n) THROW_RUNTIME_ERROR ("cannot unget that many items");
+      past -= n; future += n;
+      return peek();
+    }
+    void drop() {
+      if (future == 0) push_back(nextHelper());
+      past++; future--;
+    }
+  private:
+    size_t start,past,future;
+    std::vector<std::pair<T,ParseLocation> > buffer;
+  };
+  
+  /*! warps an iostream stream */
+  class StdStream : public Stream<int>
+  {
+  public:
+    StdStream (std::istream& cin, const std::string& name = "std::stream")
+      : cin(cin), lineNumber(1), colNumber(0), charNumber(0), name(std::shared_ptr<std::string>(new std::string(name))) {}
+    ~StdStream() {}
+    ParseLocation location() {
+      return ParseLocation(name,lineNumber,colNumber,charNumber);
+    }
+    int next() {
+      int c = cin.get();
+      if (c == '\n') { lineNumber++; colNumber = 0; } else if (c != '\r') colNumber++;
+      charNumber++;
+      return c;
+    }
+  private:
+    std::istream& cin;
+    ssize_t lineNumber;           /// the line number the token is from
+    ssize_t colNumber;            /// the character number in the current line
+    ssize_t charNumber;           /// the character in the file
+    std::shared_ptr<std::string> name;             /// name of buffer
+  };
+
+  /*! creates a stream from a file */
+  class FileStream : public Stream<int>
+  {
+  public:
+    FileStream (const FileName& fileName)
+      : lineNumber(1), colNumber(0), charNumber(0), name(std::shared_ptr<std::string>(new std::string(fileName.str())))
+    {
+      if (ifs) ifs.close();
+      ifs.open(fileName.str());
+      if (!ifs.is_open()) THROW_RUNTIME_ERROR("cannot open file " + fileName.str());
+    }
+    ~FileStream() { 
+      if (ifs) ifs.close();
+    }
+
+  public:
+    ParseLocation location() {
+      return ParseLocation(name,lineNumber,colNumber,charNumber);
+    }
+
+    int next() {
+      int c = ifs.get();
+      if (c == '\n') { lineNumber++; colNumber = 0; } else if (c != '\r') colNumber++;
+      charNumber++;
+      return c;
+    }
+
+
+  private:
+    std::ifstream ifs;
+    ssize_t lineNumber;           /// the line number the token is from
+    ssize_t colNumber;            /// the character number in the current line
+    ssize_t charNumber;           /// the character in the file
+    std::shared_ptr<std::string> name;             /// name of buffer
+  };
+
+  /*! creates a stream from a string */
+  class StrStream : public Stream<int>
+  {
+  public:
+
+    StrStream (const char* str)
+      : str(str), lineNumber(1), colNumber(0), charNumber(0) {}
+
+  public:
+    ParseLocation location() {
+      return ParseLocation(std::shared_ptr<std::string>(),lineNumber,colNumber,charNumber);
+    }
+
+    int next() {
+      int c = str[charNumber];
+      if (c == 0) return EOF;
+      if (c == '\n') { lineNumber++; colNumber = 0; } else if (c != '\r') colNumber++;
+      charNumber++;
+      return c;
+    }
+
+  private:
+    const char* str;
+    ssize_t lineNumber;           /// the line number the token is from
+    ssize_t colNumber;            /// the character number in the current line
+    ssize_t charNumber;           /// the character in the file
+  };
+
+  /*! creates a character stream from a command line */
+  class CommandLineStream : public Stream<int>
+  {
+  public:
+    CommandLineStream (int argc, char** argv, const std::string& name = "command line")
+      : i(0), j(0), charNumber(0), name(std::shared_ptr<std::string>(new std::string(name)))
+    {
+      if (argc > 0) {
+	for (size_t i=0; argv[0][i] && i<1024; i++) charNumber++;
+	charNumber++;
+      }
+      for (ssize_t k=1; k<argc; k++) args.push_back(argv[k]);
+    }
+    ~CommandLineStream() {}
+  public:
+    ParseLocation location() {
+      return ParseLocation(name,0,charNumber,charNumber);
+    }
+    int next() {
+      if (i == args.size()) return EOF;
+      if (j == args[i].size()) { i++; j=0; charNumber++; return ' '; }
+      charNumber++;
+      return args[i][j++];
+    }
+  private:
+    size_t i,j;
+    std::vector<std::string> args;
+    ssize_t charNumber;           /// the character in the file
+    std::shared_ptr<std::string> name;             /// name of buffer
+  };
+}