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/*
cpptempl ================= This is a template engine for C++.
Syntax ================= Variables: {$variable_name} Loops: {% for person in people %}Name: {$person.name}{% endfor %} If: {% for person.name == "Bob" %}Full name: Robert{% endif %}
Copyright ================== Author: Ryan Ginstrom MIT License
Usage ======================= std::string text = "{% if item %}{$item}{% endif %}\n" "{% if thing %}{$thing}{% endif %}" ; cpptempl::data_map data ; data["item"] = cpptempl::make_data("aaa") ; data["thing"] = cpptempl::make_data("bbb") ;
std::string result = cpptempl::parse(text, data) ;
Handy Functions ======================== make_data() : Feed it a string, data_map, or data_list to create a data entry. Example: data_map person ; person["name"] = make_data("Bob") ; person["occupation"] = make_data("Plumber") ; data_map data ; data["person"] = make_data(person) ; std::string result = parse(templ_text, data) ;
*/ #pragma once
#ifdef _WIN32
#pragma warning( disable : 4996 ) // 'std::copy': Function call with parameters that may be unsafe - this call relies on the caller to check that the passed values are correct. To disable this warning, use -D_SCL_SECURE_NO_WARNINGS. See documentation on how to use Visual C++ 'Checked Iterators'
#pragma warning( disable : 4512 ) // 'std::copy': Function call with parameters that may be unsafe - this call relies on the caller to check that the passed values are correct. To disable this warning, use -D_SCL_SECURE_NO_WARNINGS. See documentation on how to use Visual C++ 'Checked Iterators'
#endif
#include <string>
#include <vector>
#include <map>
#include <memory>
#include <unordered_map>
#include <boost/lexical_cast.hpp>
#include <iostream>
namespace cpptempl { // various typedefs
// data classes
class Data ; class DataValue ; class DataList ; class DataMap ;
class data_ptr { public: data_ptr() {} template<typename T> data_ptr(const T& data) { this->operator =(data); } data_ptr(DataValue* data); data_ptr(DataList* data); data_ptr(DataMap* data); data_ptr(const data_ptr& data) { ptr = data.ptr; } template<typename T> void operator = (const T& data); void push_back(const data_ptr& data); virtual ~data_ptr() {} Data* operator ->() { return ptr.get(); } private: std::shared_ptr<Data> ptr; }; typedef std::vector<data_ptr> data_list ;
class data_map { public: data_ptr& operator [](const std::string& key); bool empty(); bool has(const std::string& key); private: std::unordered_map<std::string, data_ptr> data; };
template<> inline void data_ptr::operator = (const data_ptr& data); template<> void data_ptr::operator = (const std::string& data); template<> void data_ptr::operator = (const std::string& data); template<> void data_ptr::operator = (const data_map& data); template<typename T> void data_ptr::operator = (const T& data) { std::string data_str = boost::lexical_cast<std::string>(data); this->operator =(data_str); }
// token classes
class Token ; typedef std::shared_ptr<Token> token_ptr ; typedef std::vector<token_ptr> token_vector ;
// Custom exception class for library errors
class TemplateException : public std::exception { public: TemplateException(std::string reason) : m_reason(reason){} ~TemplateException() {} const char* what() const noexcept { return m_reason.c_str(); } private: std::string m_reason; };
// Data types used in templates
class Data { public: virtual ~Data() {} virtual bool empty() = 0 ; virtual std::string getvalue(); virtual data_list& getlist(); virtual data_map& getmap() ; };
class DataValue : public Data { std::string m_value ; public: DataValue(std::string value) : m_value(value){} std::string getvalue(); bool empty(); };
class DataList : public Data { data_list m_items ; public: DataList(const data_list &items) : m_items(items){} data_list& getlist() ; bool empty(); };
class DataMap : public Data { data_map m_items ; public: DataMap(const data_map &items) : m_items(items){} data_map& getmap(); bool empty(); };
// convenience functions for making data objects
inline data_ptr make_data(std::string val) { return data_ptr(new DataValue(val)) ; } inline data_ptr make_data(data_list &val) { return data_ptr(new DataList(val)) ; } inline data_ptr make_data(data_map &val) { return data_ptr(new DataMap(val)) ; } // get a data value from a data map
// e.g. foo.bar => data["foo"]["bar"]
data_ptr parse_val(std::string key, data_map &data) ;
typedef enum { TOKEN_TYPE_NONE, TOKEN_TYPE_TEXT, TOKEN_TYPE_VAR, TOKEN_TYPE_IF, TOKEN_TYPE_FOR, TOKEN_TYPE_ENDIF, TOKEN_TYPE_ENDFOR, } TokenType;
// Template tokens
// base class for all token types
class Token { public: virtual ~Token() {}; virtual TokenType gettype() = 0 ; virtual void gettext(std::ostream &stream, data_map &data) = 0 ; virtual void set_children(token_vector &children); virtual token_vector & get_children(); };
// normal text
class TokenText : public Token { std::string m_text ; public: TokenText(std::string text) : m_text(text){} TokenType gettype(); void gettext(std::ostream &stream, data_map &data); };
// variable
class TokenVar : public Token { std::string m_key ; public: TokenVar(std::string key) : m_key(key){} TokenType gettype(); void gettext(std::ostream &stream, data_map &data); };
// for block
class TokenFor : public Token { public: std::string m_key ; std::string m_val ; token_vector m_children ; TokenFor(std::string expr); TokenType gettype(); void gettext(std::ostream &stream, data_map &data); void set_children(token_vector &children); token_vector &get_children(); };
// if block
class TokenIf : public Token { public: std::string m_expr ; token_vector m_children ; TokenIf(std::string expr) : m_expr(expr){} TokenType gettype(); void gettext(std::ostream &stream, data_map &data); bool is_true(std::string expr, data_map &data); void set_children(token_vector &children); token_vector &get_children(); };
// end of block
class TokenEnd : public Token // end of control block
{ std::string m_type ; public: TokenEnd(std::string text) : m_type(text){} TokenType gettype(); void gettext(std::ostream &stream, data_map &data); };
std::string gettext(token_ptr token, data_map &data) ;
void parse_tree(token_vector &tokens, token_vector &tree, TokenType until=TOKEN_TYPE_NONE) ; token_vector & tokenize(std::string text, token_vector &tokens) ;
// The big daddy. Pass in the template and data,
// and get out a completed doc.
void parse(std::ostream &stream, std::string templ_text, data_map &data) ; std::string parse(std::string templ_text, data_map &data); std::string parse(std::string templ_text, data_map &data); }
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