fork download
copy 
  1. #include <iostream>
  2. #include <functional>
  3. #include <vector>
  4. #include <string>
  5. #include <sstream>
  6. #include <algorithm>
  7. #include <unordered_map>
  8. #include <iterator>
  9. #include <cassert>
  10. using namespace std;
  11.  
  12. //boring helper functions
  13. inline std::string trim(const std::string &s) {
  14.    auto  wsfront=std::find_if_not(s.begin(),s.end(),[](int c){return std::isspace(c);});
  15.    return std::string(wsfront,std::find_if_not(s.rbegin(),std::string::const_reverse_iterator(wsfront),[](int c){return std::isspace(c);}).base());
  16. }
  17.  
  18. vector<string> str_to_tokens(string const &src) {
  19. 	istringstream stream(src);
  20. 	return {
  21. 		istream_iterator<string>{stream},
  22. 		istream_iterator<string>{}
  23. 	};
  24. }
  25.  
  26. string join(vector<string> const &vec, string const &delim) {
  27.     stringstream res;
  28.     copy(vec.begin(), vec.end(), ostream_iterator<string>(res, delim.c_str()));
  29.     return res.str();
  30. }
  31.  
  32. //scaffolding
  33. using arguments = vector<string>;
  34. using command = function<void(arguments const &)>;
  35. using commands = unordered_map<string, command>;
  36. using middleware = function<void(arguments &)>;
  37. using middlewares = vector<middleware>;
  38.  
  39. //bullshit that matters
  40. void print(arguments const &args) {
  41. 	for(auto &&arg: args) {
  42. 		cout << arg << " ";
  43. 	}
  44. 	cout << endl;
  45. }
  46.  
  47. struct data_store {
  48. 	using vname = string;
  49. 	using vval = string;
  50. 	unordered_map<vname, vval> vars;
  51.  
  52. 	void store(vname const &name, vval const &val) {
  53. 		vars[name] = val;
  54. 	}
  55.  
  56. 	void store_cmd(arguments const &args) {
  57. 		enum { VNAME, VEQSIGN, VVAL_BEG };
  58. 		assert(args[VEQSIGN] == "=");
  59. 		auto val = join({begin(args)+VVAL_BEG, end(args)}, " ");
  60. 		store(args[VNAME], trim(val));
  61. 	}
  62.  
  63. 	vval get(vname const &name) const {
  64. 		return vars.at(name);
  65. 	}
  66. };
  67.  
  68. void replace_vars_with_values(data_store const &store, string const &var_prefix, arguments &args) {
  69. 	for(auto &arg: args) {
  70. 		if(arg.rfind(var_prefix, 0) == 0) {
  71. 			arg = store.get(string{begin(arg)+var_prefix.size(), end(arg)});
  72. 		}
  73. 	}
  74. }
  75.  
  76. void apply_middlewares(middlewares const &mdws, arguments &args) {
  77. 	for(auto &&mdw: mdws) {
  78. 		mdw(args);
  79. 	}
  80. }
  81.  
  82. int main() {
  83. 	string var_prefix = "$";
  84. 	data_store dstore;
  85.  
  86. 	middlewares mdws = {
  87. 		[&](arguments &args) { return replace_vars_with_values(dstore, var_prefix, args); }
  88. 	};
  89.  
  90. 	commands cmds = {
  91. 		{"print", print},
  92. 		{"var", [&dstore](arguments const &args) { dstore.store_cmd(args); }}
  93. 	};
  94.  
  95. 	string input;
  96. 	while(getline(cin, input)) {
  97. 		if(input.empty()) {
  98. 			continue;
  99. 		}
  100. 		auto tokens = str_to_tokens(input);
  101. 		apply_middlewares(mdws, tokens);
  102.  
  103. 		enum { FUNC_POS, ARGS_START };
  104.  
  105. 		cmds.at(tokens[FUNC_POS])(arguments{begin(tokens)+ARGS_START, end(tokens)});
  106. 	}
  107. 	return 0;
  108. }
Success #stdin #stdout 0s 16072KB
comments (?)
stdin
copy 
var person = Ala
var state = ma dziwnego kota.
var f = print

$f $person $state
stdout
copy 
Ala ma dziwnego kota.
https://ideone.com/kdaGqy
language:
C++14 (gcc 8.3)
created:
7 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!