ast.hpp

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#ifndef __STAN__GM__AST_HPP__
#define __STAN__GM__AST_HPP__

#include <map>
#include <vector>

#include <boost/variant/recursive_variant.hpp>

namespace stan {

  namespace gm {

    struct nil { };

    // components of abstract syntax tree 
    struct array_literal;
    struct assignment;
    struct binary_op;
    struct conditional_statement;
    struct distribution;
    struct double_var_decl;
    struct double_literal;
    struct expression;
    struct for_statement;
    struct fun;
    struct identifier;
    struct index_op;
    struct int_literal;
    struct inv_var_decl;
    struct matrix_var_decl;
    struct no_op_statement;
    struct ordered_var_decl;
    struct positive_ordered_var_decl;
    struct print_statement;
    struct program;
    struct range;
    struct row_vector_var_decl;
    struct sample;
    struct simplex_var_decl;
    struct unit_vector_var_decl;
    struct statement;
    struct statements;
    struct unary_op;
    struct variable;
    struct variable_dims;
    struct var_decl;
    struct var_type;
    struct vector_var_decl;
    struct while_statement;

    // forward declarable enum hack (can't fwd-decl enum)
    typedef int base_expr_type;
    const int INT_T = 1;
    const int DOUBLE_T = 2;
    const int VECTOR_T = 3;
    const int ROW_VECTOR_T = 4;
    const int MATRIX_T = 5;
    const int ILL_FORMED_T = 6;

    std::ostream& write_base_expr_type(std::ostream& o, base_expr_type type);

    struct expr_type {
      base_expr_type base_type_;
      size_t num_dims_;
      expr_type();
      expr_type(const base_expr_type base_type); 
      expr_type(const base_expr_type base_type,
                size_t num_dims); 
      bool operator==(const expr_type& et) const;
      bool operator!=(const expr_type& et) const;
      bool is_primitive() const;
      bool is_primitive_int() const;
      bool is_primitive_double() const;
      bool is_ill_formed() const;
      base_expr_type type() const;
      size_t num_dims() const;
    };

    std::ostream& operator<<(std::ostream& o, const expr_type& et);

    expr_type promote_primitive(const expr_type& et);

    expr_type promote_primitive(const expr_type& et1,
                                const expr_type& et2);

    typedef std::pair<expr_type, std::vector<expr_type> > function_signature_t;

    class function_signatures {
    public:
      static function_signatures& instance();
      void add(const std::string& name,
               const expr_type& result_type,
               const std::vector<expr_type>& arg_types);
      void add(const std::string& name,
               const expr_type& result_type);
      void add(const std::string& name,
               const expr_type& result_type,
               const expr_type& arg_type);
      void add(const std::string& name,
               const expr_type& result_type,
               const expr_type& arg_type1,
               const expr_type& arg_type2);
      void add(const std::string& name,
               const expr_type& result_type,
               const expr_type& arg_type1,
               const expr_type& arg_type2,
               const expr_type& arg_type3);
      void add(const std::string& name,
               const expr_type& result_type,
               const expr_type& arg_type1,
               const expr_type& arg_type2,
               const expr_type& arg_type3,
               const expr_type& arg_type4);
      void add(const std::string& name,
               const expr_type& result_type,
               const expr_type& arg_type1,
               const expr_type& arg_type2,
               const expr_type& arg_type3,
               const expr_type& arg_type4,
               const expr_type& arg_type5);
      void add_nullary(const::std::string& name);
      void add_unary(const::std::string& name);
      void add_binary(const::std::string& name);
      void add_ternary(const::std::string& name);
      void add_quaternary(const::std::string& name);
      int num_promotions(const std::vector<expr_type>& call_args,
                         const std::vector<expr_type>& sig_args);
      expr_type get_result_type(const std::string& name,
                                const std::vector<expr_type>& args,
                                std::ostream& error_msgs);
    private:
      function_signatures(); 
      function_signatures(const function_signatures& fs);
      std::map<std::string, std::vector<function_signature_t> > sigs_map_;
      static function_signatures* sigs_;  // init below outside of class
    };
    
    struct statements {
      std::vector<var_decl> local_decl_;
      std::vector<statement> statements_;
      statements();
      statements(const std::vector<var_decl>& local_decl,
                 const std::vector<statement>& stmts);
    };


    struct distribution {
      std::string family_;
      std::vector<expression> args_;
    };

    struct expression_type_vis : public boost::static_visitor<expr_type> {
      expr_type operator()(const nil& e) const;
      expr_type operator()(const int_literal& e) const;
      expr_type operator()(const double_literal& e) const;
      expr_type operator()(const array_literal& e) const;
      expr_type operator()(const variable& e) const;
      expr_type operator()(const fun& e) const;
      expr_type operator()(const index_op& e) const;
      expr_type operator()(const binary_op& e) const;
      expr_type operator()(const unary_op& e) const;
      // template <typename T> expr_type operator()(const T& e) const;
    };

    


    struct expression;

    struct expression {
      typedef boost::variant<boost::recursive_wrapper<nil>, 
                             boost::recursive_wrapper<int_literal>,
                             boost::recursive_wrapper<double_literal>,
                             boost::recursive_wrapper<array_literal>,
                             boost::recursive_wrapper<variable>,
                             boost::recursive_wrapper<fun>,
                             boost::recursive_wrapper<index_op>,
                             boost::recursive_wrapper<binary_op>,
                             boost::recursive_wrapper<unary_op> > 
      expression_t;

      expression();
      expression(const expression& e);

      // template <typename Expr> expression(const Expr& expr);
      expression(const nil& expr);
      expression(const int_literal& expr);
      expression(const double_literal& expr);
      expression(const array_literal& expr);
      expression(const variable& expr);
      expression(const fun& expr);
      expression(const index_op& expr);
      expression(const binary_op& expr);
      expression(const unary_op& expr);
      expression(const expression_t& expr_);

      expr_type expression_type() const; 

      expression& operator+=(const expression& rhs);
      expression& operator-=(const expression& rhs);
      expression& operator*=(const expression& rhs);
      expression& operator/=(const expression& rhs);

      expression_t expr_;
    };

    // struct contains_var : public boost::static_visitor<bool> {
    //   const variable_map& var_map_;
    //   contains_var(const variable_map& var_map);
    //   bool operator()(const nil& e) const;
    //   bool operator()(const int_literal& e) const;
    //   bool operator()(const double_literal& e) const;
    //   bool operator()(const array_literal& e) const;
    //   bool operator()(const variable& e) const;
    //   bool operator()(const fun& e) const;
    //   bool operator()(const index_op& e) const;
    //   bool operator()(const binary_op& e) const;
    //   bool operator()(const unary_op& e) const;
    // };

    struct printable {
      typedef boost::variant<boost::recursive_wrapper<std::string>,
                             boost::recursive_wrapper<expression> >
      printable_t;

    printable();
    printable(const expression& expression);
    printable(const std::string& msg);
    printable(const printable_t& printable);
    printable(const printable& printable);

    printable_t printable_;
  };

  struct is_nil_op : public boost::static_visitor<bool> {
    bool operator()(const nil& x) const;
    bool operator()(const int_literal& x) const;
    bool operator()(const double_literal& x) const;
    bool operator()(const array_literal& x) const;
    bool operator()(const variable& x) const;
    bool operator()(const fun& x) const;
    bool operator()(const index_op& x) const;
    bool operator()(const binary_op& x) const;
    bool operator()(const unary_op& x) const;

    // template <typename T>
    // bool operator()(const T& x) const;
  };

  bool is_nil(const expression& e);

  struct variable_dims {
    std::string name_;
    std::vector<expression> dims_;
    variable_dims();
    variable_dims(std::string const& name,
                  std::vector<expression> const& dims); 
  };


  struct int_literal {
    int val_;
    expr_type type_;
    int_literal();
    int_literal(int val);
    int_literal(const int_literal& il);
    int_literal& operator=(const int_literal& il);
  };


  struct double_literal {
    double val_;
    expr_type type_;
    double_literal();
    double_literal(double val);
    double_literal& operator=(const double_literal& dl);
  };

  struct array_literal {
    std::vector<expression> args_;
    expr_type type_;
    array_literal();
    array_literal(const std::vector<expression>& args);
    array_literal& operator=(const array_literal& al);
  };

  struct variable {
    std::string name_;
    expr_type type_;
    variable();
    variable(std::string name);
    void set_type(const base_expr_type& base_type, 
                  size_t num_dims);
  };

  struct fun {
    std::string name_;
    std::vector<expression> args_;
    expr_type type_;
    fun();
    fun(std::string const& name,
        std::vector<expression> const& args); 
    void infer_type();  // FIXME: is this used anywhere?
  };

  size_t total_dims(const std::vector<std::vector<expression> >& dimss);

  expr_type infer_type_indexing(const base_expr_type& expr_base_type,
                                size_t num_expr_dims,
                                size_t num_index_dims);

  expr_type infer_type_indexing(const expression& expr,
                                size_t num_index_dims);


  struct index_op {
    expression expr_;
    std::vector<std::vector<expression> > dimss_;
    expr_type type_;
    index_op();
    // vec of vec for e.g., e[1,2][3][4,5,6]
    index_op(const expression& expr,
             const std::vector<std::vector<expression> >& dimss);
    void infer_type();
  };


  struct binary_op {
    std::string op;
    expression left;
    expression right;
    expr_type type_;
    binary_op();
    binary_op(const expression& left,
              const std::string& op,
              const expression& right);
  };

  struct unary_op {
    char op;
    expression subject;
    expr_type type_;
    unary_op(char op,
             expression const& subject);
  };

  struct range {
    expression low_;
    expression high_;
    range();
    range(expression const& low,
          expression const& high);
    bool has_low() const;
    bool has_high() const;
  };

  typedef int var_origin;
  const int data_origin = 1;
  const int transformed_data_origin = 2;
  const int parameter_origin = 3;
  const int transformed_parameter_origin = 4;
  const int derived_origin = 5;
  const int local_origin = 6;



  void print_var_origin(std::ostream& o, const var_origin& vo);

  struct base_var_decl {
    std::string name_;
    std::vector<expression> dims_;
    base_expr_type base_type_;
    base_var_decl();
    base_var_decl(const base_expr_type& base_type); 
    base_var_decl(const std::string& name,
                  const std::vector<expression>& dims,
                  const base_expr_type& base_type);
  };

  struct variable_map {
    typedef std::pair<base_var_decl,var_origin> range_t;
    std::map<std::string, range_t> map_;
    bool exists(const std::string& name) const;
    base_var_decl get(const std::string& name) const;
    base_expr_type get_base_type(const std::string& name) const;
    size_t get_num_dims(const std::string& name) const;
    var_origin get_origin(const std::string& name) const;
    void add(const std::string& name,
             const base_var_decl& base_decl,
             const var_origin& vo);
    void remove(const std::string& name);
  };

  struct int_var_decl : public base_var_decl {
    range range_;
    int_var_decl(); 
    int_var_decl(range const& range,
                 std::string const& name,
                 std::vector<expression> const& dims); 
  };


  struct double_var_decl : public base_var_decl {
    range range_;
    double_var_decl();
    double_var_decl(range const& range,
                    std::string const& name,
                    std::vector<expression> const& dims);
  };

  struct unit_vector_var_decl : public base_var_decl {
    expression K_;
    unit_vector_var_decl();
    unit_vector_var_decl(expression const& K,
                         std::string const& name,
                         std::vector<expression> const& dims);
  };

  struct simplex_var_decl : public base_var_decl {
    expression K_;
    simplex_var_decl();
    simplex_var_decl(expression const& K,
                     std::string const& name,
                     std::vector<expression> const& dims);
  };

  struct ordered_var_decl : public base_var_decl {
    expression K_;
    ordered_var_decl();
    ordered_var_decl(expression const& K,
                     std::string const& name,
                     std::vector<expression> const& dims);
  };

  struct positive_ordered_var_decl : public base_var_decl {
    expression K_;
    positive_ordered_var_decl();
    positive_ordered_var_decl(expression const& K,
                              std::string const& name,
                              std::vector<expression> const& dims);
  };

  struct vector_var_decl : public base_var_decl {
    range range_;
    expression M_;
    vector_var_decl();
    vector_var_decl(range const& range, 
                    expression const& M,
                    std::string const& name,
                    std::vector<expression> const& dims);
  };

  struct row_vector_var_decl : public base_var_decl {
    range range_;
    expression N_;
    row_vector_var_decl();
    row_vector_var_decl(range const& range, 
                        expression const& N,
                        std::string const& name,
                        std::vector<expression> const& dims);
  };

  struct matrix_var_decl : public base_var_decl {
    range range_;
    expression M_;
    expression N_;
    matrix_var_decl();
    matrix_var_decl(range const& range, 
                    expression const& M,
                    expression const& N,
                    std::string const& name,
                    std::vector<expression> const& dims);
  };

   

   

  struct cov_matrix_var_decl : public base_var_decl {
    expression K_;
    cov_matrix_var_decl();
    cov_matrix_var_decl(expression const& K,
                        std::string const& name,
                        std::vector<expression> const& dims);
  };



  struct corr_matrix_var_decl : public base_var_decl {
    expression K_;
    corr_matrix_var_decl();
    corr_matrix_var_decl(expression const& K,
                         std::string const& name,
                         std::vector<expression> const& dims);
  };



  struct name_vis : public boost::static_visitor<std::string> {
    name_vis();
    std::string operator()(const nil& x) const;
    std::string operator()(const int_var_decl& x) const;
    std::string operator()(const double_var_decl& x) const;
    std::string operator()(const vector_var_decl& x) const;
    std::string operator()(const row_vector_var_decl& x) const;
    std::string operator()(const matrix_var_decl& x) const;
    std::string operator()(const simplex_var_decl& x) const;
    std::string operator()(const unit_vector_var_decl& x) const;
    std::string operator()(const ordered_var_decl& x) const;
    std::string operator()(const positive_ordered_var_decl& x) const;
    std::string operator()(const cov_matrix_var_decl& x) const;
    std::string operator()(const corr_matrix_var_decl& x) const;
  };




  struct var_decl {
    typedef boost::variant<boost::recursive_wrapper<nil>,
                           boost::recursive_wrapper<int_var_decl>,
                           boost::recursive_wrapper<double_var_decl>,
                           boost::recursive_wrapper<vector_var_decl>,
                           boost::recursive_wrapper<row_vector_var_decl>,
                           boost::recursive_wrapper<matrix_var_decl>,
                           boost::recursive_wrapper<simplex_var_decl>,
                           boost::recursive_wrapper<unit_vector_var_decl>,
                           boost::recursive_wrapper<ordered_var_decl>,
                           boost::recursive_wrapper<positive_ordered_var_decl>,
                           boost::recursive_wrapper<cov_matrix_var_decl>,
                           boost::recursive_wrapper<corr_matrix_var_decl> >
    var_decl_t;

    var_decl_t decl_;

    var_decl();

    // template <typename Decl>
    // var_decl(Decl const& decl);
    var_decl(const var_decl_t& decl);
    var_decl(const nil& decl);
    var_decl(const int_var_decl& decl);
    var_decl(const double_var_decl& decl);
    var_decl(const vector_var_decl& decl);
    var_decl(const row_vector_var_decl& decl);
    var_decl(const matrix_var_decl& decl);
    var_decl(const simplex_var_decl& decl);
    var_decl(const unit_vector_var_decl& decl);
    var_decl(const ordered_var_decl& decl);
    var_decl(const positive_ordered_var_decl& decl);
    var_decl(const cov_matrix_var_decl& decl);
    var_decl(const corr_matrix_var_decl& decl);

    std::string name() const;
  };

  struct statement {
    typedef boost::variant<boost::recursive_wrapper<nil>,
                           boost::recursive_wrapper<assignment>,
                           boost::recursive_wrapper<sample>,
                           boost::recursive_wrapper<statements>,
                           boost::recursive_wrapper<for_statement>,
                           boost::recursive_wrapper<conditional_statement>,
                           boost::recursive_wrapper<while_statement>,
                           boost::recursive_wrapper<print_statement>,
                           boost::recursive_wrapper<no_op_statement> >
    statement_t;
    
    statement_t statement_;

    statement();
    statement(const statement_t& st);

    statement(const nil& st);
    statement(const assignment& st);
    statement(const sample& st);
    statement(const statements& st);
    statement(const for_statement& st);
    statement(const conditional_statement& st);
    statement(const while_statement& st);
    statement(const print_statement& st);
    statement(const no_op_statement& st);

    // template <typename Statement>
    // statement(const Statement& statement);
  };

  struct for_statement {
    std::string variable_;
    range range_;
    statement statement_;
    for_statement();
    for_statement(std::string& variable,
                  range& range,
                  statement& stmt);
  };
    
    // bodies may be 1 longer than conditions due to else
    struct conditional_statement {
      std::vector<expression> conditions_;
      std::vector<statement> bodies_; 
      conditional_statement();
      conditional_statement(const std::vector<expression>& conditions,
                            const std::vector<statement>& statements);
    };

    struct while_statement {
      expression condition_;
      statement body_;
      while_statement();
      while_statement(const expression& condition,
                      const statement& body);
    };

  struct print_statement {
    std::vector<printable> printables_;
    print_statement();
    print_statement(const std::vector<printable>& printables);
  };


  struct no_op_statement {
    // no op, no data
  };


   
  struct program {
    std::vector<var_decl> data_decl_;
    std::pair<std::vector<var_decl>,std::vector<statement> > 
    derived_data_decl_;
    std::vector<var_decl> parameter_decl_;
    std::pair<std::vector<var_decl>,std::vector<statement> > 
    derived_decl_;
    statement statement_;
    std::pair<std::vector<var_decl>,std::vector<statement> > generated_decl_;
    program();
    program(const std::vector<var_decl>& data_decl,
            const std::pair<std::vector<var_decl>,
            std::vector<statement> >& derived_data_decl,
            const std::vector<var_decl>& parameter_decl,
            const std::pair<std::vector<var_decl>,
            std::vector<statement> >& derived_decl,
            const statement& st,
            const std::pair<std::vector<var_decl>,
            std::vector<statement> >& generated_decl);


  };

  struct sample {
    expression expr_;
    distribution dist_;
    range truncation_;
    sample();
    sample(expression& e,
           distribution& dist);
    bool is_ill_formed() const;
  };

  struct assignment {
    variable_dims var_dims_; // lhs_var[dim0,...,dimN-1] 
    expression expr_;        // = rhs
    base_var_decl var_type_; // type of lhs_var
    assignment();
    assignment(variable_dims& var_dims,
               expression& expr);
  };
  
  // FIXME:  is this next necessary dependency?
  // from generator.hpp
  void generate_expression(const expression& e, std::ostream& o);

    bool has_rng_suffix(const std::string& s);


  }
}
 
#endif