class Racc::Parser

常量

Racc_Runtime_Core_Id_C
Racc_Runtime_Core_Version_C
Racc_Runtime_Core_Version_R
Racc_Runtime_Version

公共实例方法

_racc_do_parse_rb(arg, in_debug) 点击切换源代码

# File racc-1.8.1/lib/racc/parser.rb, line 279
def _racc_do_parse_rb(arg, in_debug)
  action_table, action_check, action_default, action_pointer,
  _,            _,            _,              _,
  _,            _,            token_table,    * = arg

  _racc_init_sysvars
  tok = act = i = nil

  catch(:racc_end_parse) {
    while true
      if i = action_pointer[@racc_state[-1]]
        if @racc_read_next
          if @racc_t != 0   # not EOF
            tok, @racc_val = next_token()
            unless tok      # EOF
              @racc_t = 0
            else
              @racc_t = (token_table[tok] or 1)   # error token
            end
            racc_read_token(@racc_t, tok, @racc_val) if @yydebug
            @racc_read_next = false
          end
        end
        i += @racc_t
        unless i >= 0 and
               act = action_table[i] and
               action_check[i] == @racc_state[-1]
          act = action_default[@racc_state[-1]]
        end
      else
        act = action_default[@racc_state[-1]]
      end
      while act = _racc_evalact(act, arg)
        ;
      end
    end
  }
end

_racc_do_reduce(arg, act) 点击切换源代码

# File racc-1.8.1/lib/racc/parser.rb, line 479
def _racc_do_reduce(arg, act)
  _,          _,            _,            _,
  goto_table, goto_check,   goto_default, goto_pointer,
  nt_base,    reduce_table, _,            _,
  _,          use_result,   * = arg

  state = @racc_state
  vstack = @racc_vstack
  tstack = @racc_tstack

  i = act * -3
  len       = reduce_table[i]
  reduce_to = reduce_table[i+1]
  method_id = reduce_table[i+2]
  void_array = []

  tmp_t = tstack[-len, len] if @yydebug
  tmp_v = vstack[-len, len]
  tstack[-len, len] = void_array if @yydebug
  vstack[-len, len] = void_array
  state[-len, len]  = void_array

  # tstack must be updated AFTER method call
  if use_result
    vstack.push __send__(method_id, tmp_v, vstack, tmp_v[0])
  else
    vstack.push __send__(method_id, tmp_v, vstack)
  end
  tstack.push reduce_to

  racc_reduce(tmp_t, reduce_to, tstack, vstack) if @yydebug

  k1 = reduce_to - nt_base
  if i = goto_pointer[k1]
    i += state[-1]
    if i >= 0 and (curstate = goto_table[i]) and goto_check[i] == k1
      return curstate
    end
  end
  goto_default[k1]
end

_racc_evalact(act, arg) 点击切换源代码

通用

# File racc-1.8.1/lib/racc/parser.rb, line 382
def _racc_evalact(act, arg)
  action_table, action_check, _, action_pointer,
  _,            _,            _, _,
  _,            _,            _, shift_n,
  reduce_n,     * = arg
  nerr = 0   # tmp

  if act > 0 and act < shift_n
    #
    # shift
    #
    if @racc_error_status > 0
      @racc_error_status -= 1 unless @racc_t <= 1 # error token or EOF
    end
    @racc_vstack.push @racc_val
    @racc_state.push act
    @racc_read_next = true
    if @yydebug
      @racc_tstack.push @racc_t
      racc_shift @racc_t, @racc_tstack, @racc_vstack
    end

  elsif act < 0 and act > -reduce_n
    #
    # reduce
    #
    code = catch(:racc_jump) {
      @racc_state.push _racc_do_reduce(arg, act)
      false
    }
    if code
      case code
      when 1 # yyerror
        @racc_user_yyerror = true   # user_yyerror
        return -reduce_n
      when 2 # yyaccept
        return shift_n
      else
        raise '[Racc Bug] unknown jump code'
      end
    end

  elsif act == shift_n
    #
    # accept
    #
    racc_accept if @yydebug
    throw :racc_end_parse, @racc_vstack[0]

  elsif act == -reduce_n
    #
    # error
    #
    case @racc_error_status
    when 0
      unless arg[21]    # user_yyerror
        nerr += 1
        on_error @racc_t, @racc_val, @racc_vstack
      end
    when 3
      if @racc_t == 0   # is $
        # We're at EOF, and another error occurred immediately after
        # attempting auto-recovery
        throw :racc_end_parse, nil
      end
      @racc_read_next = true
    end
    @racc_user_yyerror = false
    @racc_error_status = 3
    while true
      if i = action_pointer[@racc_state[-1]]
        i += 1   # error token
        if  i >= 0 and
            (act = action_table[i]) and
            action_check[i] == @racc_state[-1]
          break
        end
      end
      throw :racc_end_parse, nil if @racc_state.size <= 1
      @racc_state.pop
      @racc_vstack.pop
      if @yydebug
        @racc_tstack.pop
        racc_e_pop @racc_state, @racc_tstack, @racc_vstack
      end
    end
    return act

  else
    raise "[Racc Bug] unknown action #{act.inspect}"
  end

  racc_next_state(@racc_state[-1], @racc_state) if @yydebug

  nil
end

_racc_init_sysvars() 点击切换源代码

# File racc-1.8.1/lib/racc/parser.rb, line 232
def _racc_init_sysvars
  @racc_state  = [0]
  @racc_tstack = []
  @racc_vstack = []

  @racc_t = nil
  @racc_val = nil

  @racc_read_next = true

  @racc_user_yyerror = false
  @racc_error_status = 0
end

_racc_setup() 点击切换源代码

# File racc-1.8.1/lib/racc/parser.rb, line 220
def _racc_setup
  @yydebug = false unless self.class::Racc_debug_parser
  @yydebug = false unless defined?(@yydebug)
  if @yydebug
    @racc_debug_out = $stderr unless defined?(@racc_debug_out)
    @racc_debug_out ||= $stderr
  end
  arg = self.class::Racc_arg
  arg[13] = true if arg.size < 14
  arg
end

_racc_yyparse_rb(recv, mid, arg, c_debug) 点击切换源代码

# File racc-1.8.1/lib/racc/parser.rb, line 329
def _racc_yyparse_rb(recv, mid, arg, c_debug)
  action_table, action_check, action_default, action_pointer,
  _,            _,            _,              _,
  _,            _,            token_table,    * = arg

  _racc_init_sysvars

  catch(:racc_end_parse) {
    until i = action_pointer[@racc_state[-1]]
      while act = _racc_evalact(action_default[@racc_state[-1]], arg)
        ;
      end
    end
    recv.__send__(mid) do |tok, val|
      unless tok
        @racc_t = 0
      else
        @racc_t = (token_table[tok] or 1)   # error token
      end
      @racc_val = val
      @racc_read_next = false

      i += @racc_t
      unless i >= 0 and
             act = action_table[i] and
             action_check[i] == @racc_state[-1]
        act = action_default[@racc_state[-1]]
      end
      while act = _racc_evalact(act, arg)
        ;
      end

      while !(i = action_pointer[@racc_state[-1]]) ||
            ! @racc_read_next ||
            @racc_t == 0  # $
        unless i and i += @racc_t and
               i >= 0 and
               act = action_table[i] and
               action_check[i] == @racc_state[-1]
          act = action_default[@racc_state[-1]]
        end
        while act = _racc_evalact(act, arg)
          ;
        end
      end
    end
  }
end

next_token() 点击切换源代码

获取下一个 token 的方法。如果你使用 do_parse 方法，你必须实现 next_token。

返回值的格式是 [TOKEN_SYMBOL, VALUE]。token-symbol 默认用 Ruby 的 symbol 表示，例如，:IDENT 表示 ‘IDENT’。“;” (String) 表示 ‘;’。

最终的符号（文件结束）必须为 false。

# File racc-1.8.1/lib/racc/parser.rb, line 275
def next_token
  raise NotImplementedError, "#{self.class}\#next_token is not defined"
end

on_error(t, val, vstack) 点击切换源代码

当发现解析错误时，会调用此方法。

ERROR_TOKEN_ID 是导致错误的 token 的内部 ID。你可以通过调用 token_to_str 获取此 ID 的字符串表示。

ERROR_VALUE 是错误 token 的值。

value_stack 是符号值的堆栈。请勿修改此对象。

此方法默认会引发 ParseError 异常。

如果此方法返回，解析器将进入“错误恢复模式”。

# File racc-1.8.1/lib/racc/parser.rb, line 535
def on_error(t, val, vstack)
  raise ParseError, sprintf("parse error on value %s (%s)",
                            val.inspect, token_to_str(t) || '?')
end

racc_accept() 点击切换源代码

# File racc-1.8.1/lib/racc/parser.rb, line 584
def racc_accept
  @racc_debug_out.puts 'accept'
  @racc_debug_out.puts
end

racc_e_pop(state, tstack, vstack) 点击切换源代码

# File racc-1.8.1/lib/racc/parser.rb, line 589
def racc_e_pop(state, tstack, vstack)
  @racc_debug_out.puts 'error recovering mode: pop token'
  racc_print_states state
  racc_print_stacks tstack, vstack
  @racc_debug_out.puts
end

racc_next_state(curstate, state) 点击切换源代码

# File racc-1.8.1/lib/racc/parser.rb, line 596
def racc_next_state(curstate, state)
  @racc_debug_out.puts  "goto    #{curstate}"
  racc_print_states state
  @racc_debug_out.puts
end

racc_print_stacks(t, v) 点击切换源代码

# File racc-1.8.1/lib/racc/parser.rb, line 602
def racc_print_stacks(t, v)
  out = @racc_debug_out
  out.print '        ['
  t.each_index do |i|
    out.print ' (', racc_token2str(t[i]), ' ', v[i].inspect, ')'
  end
  out.puts ' ]'
end

racc_print_states(s) 点击切换源代码

# File racc-1.8.1/lib/racc/parser.rb, line 611
def racc_print_states(s)
  out = @racc_debug_out
  out.print '        ['
  s.each {|st| out.print ' ', st }
  out.puts ' ]'
end

racc_read_token(t, tok, val) 点击切换源代码

用于调试输出

# File racc-1.8.1/lib/racc/parser.rb, line 558
def racc_read_token(t, tok, val)
  @racc_debug_out.print 'read    '
  @racc_debug_out.print tok.inspect, '(', racc_token2str(t), ') '
  @racc_debug_out.puts val.inspect
  @racc_debug_out.puts
end

racc_reduce(toks, sim, tstack, vstack) 点击切换源代码

# File racc-1.8.1/lib/racc/parser.rb, line 571
def racc_reduce(toks, sim, tstack, vstack)
  out = @racc_debug_out
  out.print 'reduce '
  if toks.empty?
    out.print ' <none>'
  else
    toks.each {|t| out.print ' ', racc_token2str(t) }
  end
  out.puts " --> #{racc_token2str(sim)}"
  racc_print_stacks tstack, vstack
  @racc_debug_out.puts
end

racc_shift(tok, tstack, vstack) 点击切换源代码

# File racc-1.8.1/lib/racc/parser.rb, line 565
def racc_shift(tok, tstack, vstack)
  @racc_debug_out.puts "shift   #{racc_token2str tok}"
  racc_print_stacks tstack, vstack
  @racc_debug_out.puts
end

racc_token2str(tok) 点击切换源代码

# File racc-1.8.1/lib/racc/parser.rb, line 618
def racc_token2str(tok)
  self.class::Racc_token_to_s_table[tok] or
      raise "[Racc Bug] can't convert token #{tok} to string"
end

token_to_str(t) 点击切换源代码

将 token 符号的内部 ID 转换为字符串。

# File racc-1.8.1/lib/racc/parser.rb, line 624
def token_to_str(t)
  self.class::Racc_token_to_s_table[t]
end

yyaccept() 点击切换源代码

退出解析器。返回值是 Symbol_Value_Stack[0]。

# File racc-1.8.1/lib/racc/parser.rb, line 548
def yyaccept
  throw :racc_jump, 2
end

yyerrok() 点击切换源代码

离开错误恢复模式。

# File racc-1.8.1/lib/racc/parser.rb, line 553
def yyerrok
  @racc_error_status = 0
end

yyerror() 点击切换源代码

进入错误恢复模式。此方法不会调用 on_error。

# File racc-1.8.1/lib/racc/parser.rb, line 542
def yyerror
  throw :racc_jump, 1
end

私有实例方法

_racc_do_parse_c(p1, p2) 点击切换源代码

static VALUE
racc_cparse(VALUE parser, VALUE arg, VALUE sysdebug)
{
    VALUE vparams;
    struct cparse_params *v;

    vparams = TypedData_Make_Struct(CparseParams, struct cparse_params,
                                    &cparse_params_type, v);
    D_puts("starting cparse");
    v->sys_debug = RTEST(sysdebug);
    vparams = initialize_params(vparams, parser, arg, Qnil, Qnil);
    v->lex_is_iterator = FALSE;
    parse_main(v, Qnil, Qnil, 0);

    RB_GC_GUARD(vparams);
    return v->retval;
}

_racc_yyparse_c(p1, p2, p3, p4) 点击切换源代码

static VALUE
racc_yyparse(VALUE parser, VALUE lexer, VALUE lexmid, VALUE arg, VALUE sysdebug)
{
    VALUE vparams;
    struct cparse_params *v;

    vparams = TypedData_Make_Struct(CparseParams, struct cparse_params,
                                    &cparse_params_type, v);
    v->sys_debug = RTEST(sysdebug);
    D_puts("start C yyparse");
    vparams = initialize_params(vparams, parser, arg, lexer, lexmid);
    v->lex_is_iterator = TRUE;
    D_puts("params initialized");
    parse_main(v, Qnil, Qnil, 0);
    call_lexer(v);
    if (!v->fin) {
        rb_raise(rb_eArgError, "%s() is finished before EndOfToken",
                 rb_id2name(v->lexmid));
    }

    RB_GC_GUARD(vparams);
    return v->retval;
}