From 74ddd0381aa1b1a90eb0d5300fa576cb2348eeac Mon Sep 17 00:00:00 2001
From: John Denker <jsd@av8n.com>
Date: Sun, 17 Oct 2021 10:10:18 -0700
Subject: basically functional, but still a work in progress

---
 arg_parser.h | 95 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)
 create mode 100644 arg_parser.h

(limited to 'arg_parser.h')

diff --git a/arg_parser.h b/arg_parser.h
new file mode 100644
index 0000000..2ee69c6
--- /dev/null
+++ b/arg_parser.h
@@ -0,0 +1,95 @@
+#ifndef ARG_PARSER_H
+#define ARG_PARSER_H
+
+#include <iostream>
+#include <memory>
+#include <string>
+#include <list>
+#include <vector>
+#include <fstream>
+#include <sstream>      // for basic parsing
+                        // and for formatting error msgs
+#include <limits>       // for ::infinity()
+
+// TODO:  use "some_sstream >> some_int" instead of Atoi
+// since that allows more error checking
+
+#ifndef HAVE_INF
+double const Inf = std::numeric_limits<double>::infinity();
+#define HAVE_INF
+#endif
+
+std::string tolower(const std::string& arg);
+
+// This is the interfact that ordinary users use;
+// implementation in arg_parser.c is slightly tricky,
+// but users never see that.
+template<typename T> T Atox(std::string const &foo);
+
+// The base class:
+class baseGetter{
+public:
+  virtual std::string get()=0;
+  virtual int fail()=0;
+  virtual ~baseGetter(){
+//----    cerr << "dtor: baseGetter" << std::endl;
+  };
+  baseGetter(){
+//----    cerr << "basic ctor: baseGetter" << std::endl;
+  }
+};
+
+// A Getter that reads words from the command line:
+class cmdGetter : public baseGetter{
+public:
+  int argc;
+  char const * const * argv;
+  int wasgood;
+
+//ordinary constructor:
+  cmdGetter(int const _argc, char const * const * _argv);
+  virtual std::string get();
+  virtual int fail();
+};
+
+// A Getter that reads words from a file:
+class fileGetter : public baseGetter{
+public:
+  std::fstream file;
+
+//ordinary constructor:
+  fileGetter(const std::string fname);
+  virtual std::string get();
+  virtual int fail();
+  void dummy() {
+    if (Inf);
+  }
+};
+
+class arg_parser{
+public:
+  std::list <std::shared_ptr<baseGetter> > getsome;
+  std::string cur;
+  int fold_case;
+  std::string keyword;
+  int narg;             // number of args picked up using >> after this keyword
+
+// Constructor, for reading words from command line:
+  arg_parser(int const _argc, char const * const * _argv);
+// Constructor, for reading words from file:
+  arg_parser(const std::string fname);
+  void push(const std::string fname);
+  int fail();
+  template<class T=std::string> T nextArg();
+  template<class T=std::string> T nextRaw();
+
+// see if cur arg is a prefix of patt */
+  int prefix(const std::string& patt);
+  template <typename T> arg_parser& operator>>(T& val);
+  std::string xcase(const std::string& arg);
+};
+
+template<typename T> struct myTraits {static const char* name;};
+
+#define arg_parser_h
+#endif
-- 
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