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1 /* |
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2 |
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3 Copyright (C) 1996, 1997 John W. Eaton |
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4 |
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5 This file is part of Octave. |
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6 |
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7 Octave is free software; you can redistribute it and/or modify it |
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8 under the terms of the GNU General Public License as published by the |
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9 Free Software Foundation; either version 2, or (at your option) any |
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10 later version. |
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11 |
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12 Octave is distributed in the hope that it will be useful, but WITHOUT |
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13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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15 for more details. |
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16 |
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17 You should have received a copy of the GNU General Public License |
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18 along with Octave; see the file COPYING. If not, write to the Free |
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19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
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20 |
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21 */ |
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22 |
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23 #if defined (__GNUG__) |
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24 #pragma implementation |
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25 #endif |
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26 |
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27 #ifdef HAVE_CONFIG_H |
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28 #include <config.h> |
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29 #endif |
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30 |
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31 #include "str-vec.h" |
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32 |
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33 #include <defaults.h> |
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34 #include "defun.h" |
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35 #include "error.h" |
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36 #include "input.h" |
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37 #include "oct-obj.h" |
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38 #include "ov-usr-fcn.h" |
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39 #include "ov.h" |
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40 #include "pager.h" |
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2985
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41 #include "pt-jump.h" |
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2974
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42 #include "pt-misc.h" |
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43 #include "pt-pr-code.h" |
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2982
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44 #include "pt-stmt.h" |
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45 #include "pt-walk.h" |
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46 #include "symtab.h" |
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47 #include "toplev.h" |
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48 #include "unwind-prot.h" |
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49 #include "utils.h" |
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50 #include "variables.h" |
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51 |
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52 // If TRUE, variables returned from functions have default values even |
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53 // if they are not explicitly initialized. |
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54 static bool Vdefine_all_return_values; |
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55 |
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3131
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56 // Maximum nesting level for functions called recursively. |
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57 static int Vmax_recursion_depth; |
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58 |
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2974
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59 // If TRUE, the last computed value is returned from functions that |
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60 // don't actually define any return variables. |
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61 static bool Vreturn_last_computed_value; |
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62 |
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63 // User defined functions. |
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64 |
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3219
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65 DEFINE_OCTAVE_ALLOCATOR (octave_user_function); |
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66 |
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3219
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67 DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA (octave_user_function, |
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68 "user-defined function"); |
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69 |
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70 // Ugh. This really needs to be simplified (code/data? |
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71 // extrinsic/intrinsic state?). |
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72 |
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73 octave_user_function::octave_user_function |
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74 (tree_parameter_list *pl, tree_parameter_list *rl, |
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75 tree_statement_list *cl, symbol_table *st) |
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76 : octave_function (string (), string ()), |
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77 param_list (pl), ret_list (rl), cmd_list (cl), |
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3255
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78 sym_tab (st), file_name (), fcn_name (), |
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79 t_parsed (static_cast<time_t> (0)), |
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80 t_checked (static_cast<time_t> (0)), |
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81 system_fcn_file (false), call_depth (0), |
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3165
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82 num_named_args (0), args_passed (), num_args_passed (0), |
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83 curr_va_arg_number (0), vr_list (0), symtab_entry (0), |
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84 argn_sr (0), nargin_sr (0), nargout_sr (0) |
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85 { |
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86 install_automatic_vars (); |
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87 |
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88 if (param_list) |
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89 { |
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90 num_named_args = param_list->length (); |
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91 curr_va_arg_number = num_named_args; |
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92 } |
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93 } |
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94 |
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95 octave_user_function::~octave_user_function (void) |
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96 { |
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97 delete param_list; |
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98 delete ret_list; |
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99 delete sym_tab; |
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100 delete cmd_list; |
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101 delete vr_list; |
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102 } |
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103 |
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104 octave_user_function * |
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105 octave_user_function::define_ret_list (tree_parameter_list *t) |
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106 { |
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107 ret_list = t; |
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108 |
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109 if (ret_list && ret_list->takes_varargs ()) |
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110 vr_list = new tree_va_return_list; |
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111 |
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112 return this; |
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113 } |
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114 |
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115 void |
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116 octave_user_function::stash_fcn_file_name (void) |
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117 { |
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118 if (fcn_name.empty ()) |
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119 file_name = ""; |
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120 else |
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121 file_name = fcn_file_in_path (fcn_name); |
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122 } |
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123 |
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124 void |
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125 octave_user_function::mark_as_system_fcn_file (void) |
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126 { |
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127 if (! file_name.empty ()) |
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128 { |
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129 // We really should stash the whole path to the file we found, |
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130 // when we looked it up, to avoid possible race conditions... |
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131 // XXX FIXME XXX |
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132 // |
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133 // We probably also don't need to get the library directory |
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134 // every time, but since this function is only called when the |
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135 // function file is parsed, it probably doesn't matter that |
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136 // much. |
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137 |
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138 string ff_name = fcn_file_in_path (file_name); |
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139 |
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140 if (Vfcn_file_dir.compare (ff_name, 0, Vfcn_file_dir.length ()) == 0) |
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141 system_fcn_file = 1; |
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142 } |
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143 else |
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144 system_fcn_file = 0; |
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145 } |
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146 |
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147 bool |
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148 octave_user_function::takes_varargs (void) const |
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149 { |
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150 return (param_list && param_list->takes_varargs ()); |
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151 } |
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152 |
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153 octave_value |
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154 octave_user_function::octave_va_arg (void) |
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155 { |
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156 octave_value retval; |
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157 |
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158 if (curr_va_arg_number < num_args_passed) |
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159 retval = args_passed (curr_va_arg_number++); |
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160 else |
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161 ::error ("va_arg: error getting arg number %d -- only %d provided", |
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162 curr_va_arg_number + 1, num_args_passed); |
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163 |
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164 return retval; |
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165 } |
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166 |
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167 octave_value_list |
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168 octave_user_function::octave_all_va_args (void) |
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169 { |
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170 octave_value_list retval; |
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171 |
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172 int n = num_args_passed - num_named_args; |
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2974
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173 |
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3178
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174 if (n > 0) |
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175 { |
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176 retval.resize (n); |
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177 |
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178 int k = 0; |
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179 for (int i = num_named_args; i < num_args_passed; i++) |
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180 retval(k++) = args_passed(i); |
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181 } |
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182 |
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183 return retval; |
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184 } |
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185 |
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186 bool |
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187 octave_user_function::takes_var_return (void) const |
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188 { |
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189 return (ret_list && ret_list->takes_varargs ()); |
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190 } |
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191 |
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192 void |
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193 octave_user_function::octave_vr_val (const octave_value& val) |
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194 { |
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195 assert (vr_list); |
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196 |
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197 vr_list->append (val); |
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198 } |
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199 |
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200 void |
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201 octave_user_function::stash_function_name (const string& s) |
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202 { |
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203 fcn_name = s; |
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204 } |
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205 |
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206 // For unwind protect. |
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207 |
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208 static void |
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209 pop_symbol_table_context (void *table) |
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210 { |
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211 symbol_table *tmp = static_cast<symbol_table *> (table); |
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212 tmp->pop_context (); |
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213 } |
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214 |
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215 static void |
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216 delete_vr_list (void *list) |
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217 { |
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218 tree_va_return_list *tmp = static_cast<tree_va_return_list *> (list); |
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219 tmp->clear (); |
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220 delete tmp; |
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221 } |
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222 |
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223 static void |
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224 clear_symbol_table (void *table) |
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225 { |
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226 symbol_table *tmp = static_cast<symbol_table *> (table); |
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227 tmp->clear (); |
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228 } |
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229 |
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230 static void |
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3239
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231 clear_param_list (void *lst) |
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232 { |
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233 tree_parameter_list *tmp = static_cast<tree_parameter_list *> (lst); |
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234 |
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235 if (tmp) |
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236 tmp->clear (); |
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237 } |
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238 |
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239 static void |
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240 clear_args_passed (void *fcn) |
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241 { |
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242 octave_user_function *tmp = static_cast<octave_user_function *> (fcn); |
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243 |
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244 if (tmp) |
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245 tmp->clear_args_passed (); |
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246 } |
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247 |
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248 static void |
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249 unprotect_function (void *sr_arg) |
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250 { |
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251 symbol_record *sr = static_cast<symbol_record *> (sr_arg); |
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252 sr->unprotect (); |
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253 } |
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254 |
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255 octave_value_list |
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256 octave_user_function::do_index_op (int nargout, const octave_value_list& args) |
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257 { |
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258 octave_value_list retval; |
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259 |
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260 if (error_state) |
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261 return retval; |
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262 |
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263 if (! cmd_list) |
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264 return retval; |
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265 |
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266 int nargin = args.length (); |
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267 |
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2985
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268 unwind_protect::begin_frame ("func_eval"); |
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2974
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269 |
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270 unwind_protect_int (call_depth); |
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271 call_depth++; |
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272 |
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3131
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273 if (call_depth > Vmax_recursion_depth) |
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274 { |
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275 ::error ("max_recursion_limit exceeded"); |
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3321
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276 unwind_protect::run_frame ("func_eval"); |
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3131
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277 return retval; |
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278 } |
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279 |
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2974
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280 if (symtab_entry && ! symtab_entry->is_read_only ()) |
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281 { |
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282 symtab_entry->protect (); |
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2985
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283 unwind_protect::add (unprotect_function, symtab_entry); |
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2974
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284 } |
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285 |
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286 if (call_depth > 1) |
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287 { |
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288 sym_tab->push_context (); |
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2985
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289 unwind_protect::add (pop_symbol_table_context, sym_tab); |
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290 |
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291 if (vr_list) |
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292 { |
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293 // Push new vr_list. |
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294 |
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295 unwind_protect_ptr (vr_list); |
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296 vr_list = new tree_va_return_list; |
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297 |
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298 // Clear and delete the new one before restoring the old |
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299 // one. |
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300 |
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2985
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301 unwind_protect::add (delete_vr_list, vr_list); |
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2974
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302 } |
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303 } |
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304 |
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305 if (vr_list) |
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306 vr_list->clear (); |
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307 |
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308 // Force symbols to be undefined again when this function exits. |
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309 |
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2985
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310 unwind_protect::add (clear_symbol_table, sym_tab); |
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2974
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311 |
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312 // Save old and set current symbol table context, for |
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313 // eval_undefined_error(). |
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314 |
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315 unwind_protect_ptr (curr_sym_tab); |
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316 curr_sym_tab = sym_tab; |
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317 |
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318 unwind_protect_ptr (curr_function); |
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319 curr_function = this; |
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320 |
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321 // XXX FIXME XXX -- ??? |
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322 // unwind_protect_ptr (args_passed); |
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323 |
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324 args_passed = args; |
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325 |
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3239
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326 // Force cache of arguments to be undefined when this function exits. |
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327 // Doing so decrements the reference counts on the values of local |
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328 // variables that are also named function parameters. |
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329 |
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330 unwind_protect::add (::clear_args_passed, this); |
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331 |
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2974
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332 string_vector arg_names = args.name_tags (); |
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333 |
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334 unwind_protect_int (num_args_passed); |
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335 num_args_passed = nargin; |
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336 |
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337 unwind_protect_int (num_named_args); |
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338 unwind_protect_int (curr_va_arg_number); |
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339 |
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340 if (param_list && ! param_list->varargs_only ()) |
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341 { |
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342 param_list->define_from_arg_vector (args); |
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343 if (error_state) |
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344 goto abort; |
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345 } |
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346 |
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3239
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347 // Force parameter list to be undefined when this function exits. |
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348 // Doing so decrements the reference counts on the values of local |
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349 // variables that are also named function parameters. |
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350 |
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351 unwind_protect::add (clear_param_list, param_list); |
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352 |
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2974
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353 if (ret_list && Vdefine_all_return_values) |
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354 { |
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355 octave_value tmp = builtin_any_variable ("default_return_value"); |
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356 |
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357 if (tmp.is_defined ()) |
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358 ret_list->initialize_undefined_elements (tmp); |
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359 } |
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360 |
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3239
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361 // Force return list to be undefined when this function exits. |
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362 // Doing so decrements the reference counts on the values of local |
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363 // variables that are also named values returned by this function. |
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364 |
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365 unwind_protect::add (clear_param_list, ret_list); |
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366 |
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2974
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367 // The following code is in a separate scope to avoid warnings from |
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368 // G++ about `goto abort' crossing the initialization of some |
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369 // variables. |
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370 |
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371 { |
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372 bind_automatic_vars (arg_names, nargin, nargout); |
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373 |
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374 bool echo_commands = (Vecho_executing_commands & ECHO_FUNCTIONS); |
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375 |
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376 if (echo_commands) |
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377 print_code_function_header (); |
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378 |
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379 // Evaluate the commands that make up the function. |
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380 |
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381 octave_value_list tmp = cmd_list->eval (); |
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382 |
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383 octave_value last_computed_value; |
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384 |
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385 if (! tmp.empty ()) |
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386 last_computed_value = tmp(0); |
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387 |
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388 if (echo_commands) |
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389 print_code_function_trailer (); |
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390 |
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2985
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391 if (tree_return_command::returning) |
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392 tree_return_command::returning = 0; |
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2974
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393 |
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2985
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394 if (tree_break_command::breaking) |
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395 tree_break_command::breaking--; |
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2974
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396 |
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397 if (error_state) |
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398 { |
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399 traceback_error (); |
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400 goto abort; |
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401 } |
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402 |
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403 // Copy return values out. |
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404 |
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405 if (ret_list) |
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406 retval = ret_list->convert_to_const_vector (vr_list); |
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407 else if (Vreturn_last_computed_value) |
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408 retval(0) = last_computed_value; |
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409 } |
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410 |
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411 abort: |
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2985
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412 unwind_protect::run_frame ("func_eval"); |
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2974
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413 |
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414 return retval; |
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415 } |
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416 |
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417 void |
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418 octave_user_function::traceback_error (void) |
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419 { |
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420 if (error_state >= 0) |
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421 error_state = -1; |
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422 |
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423 if (fcn_name.empty ()) |
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424 { |
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425 if (file_name.empty ()) |
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426 ::error ("called from `?unknown?'"); |
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427 else |
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428 ::error ("called from file `%s'", file_name.c_str ()); |
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429 } |
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430 else |
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431 { |
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432 if (file_name.empty ()) |
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433 ::error ("called from `%s'", fcn_name.c_str ()); |
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434 else |
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435 ::error ("called from `%s' in file `%s'", |
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436 fcn_name.c_str (), file_name.c_str ()); |
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437 } |
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438 } |
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439 |
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440 void |
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441 octave_user_function::accept (tree_walker& tw) |
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442 { |
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443 tw.visit_octave_user_function (*this); |
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444 } |
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445 |
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446 void |
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447 octave_user_function::print_code_function_header (void) |
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448 { |
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449 tree_print_code tpc (octave_stdout, Vps4); |
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450 |
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451 tpc.visit_octave_user_function_header (*this); |
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452 } |
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453 |
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454 void |
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455 octave_user_function::print_code_function_trailer (void) |
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456 { |
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457 tree_print_code tpc (octave_stdout, Vps4); |
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458 |
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459 tpc.visit_octave_user_function_trailer (*this); |
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460 } |
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461 |
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462 void |
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463 octave_user_function::install_automatic_vars (void) |
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464 { |
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465 argn_sr = sym_tab->lookup ("argn", true); |
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466 nargin_sr = sym_tab->lookup ("nargin", true); |
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467 nargout_sr = sym_tab->lookup ("nargout", true); |
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468 } |
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469 |
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470 void |
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471 octave_user_function::bind_automatic_vars |
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472 (const string_vector& arg_names, int nargin, int nargout) |
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473 { |
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474 if (! arg_names.empty ()) |
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475 argn_sr->define (arg_names); |
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476 |
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477 nargin_sr->define (static_cast<double> (nargin)); |
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478 nargout_sr->define (static_cast<double> (nargout)); |
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479 } |
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480 |
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481 DEFUN (va_arg, args, , |
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3445
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482 "-*- texinfo -*-\n\ |
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483 @deftypefn {Built-in Function} {} va_arg ()\n\ |
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484 Return the value of hte next available argument and move the internal\n\ |
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485 pointer to the next argument. It is an error to call @code{va_arg}\n\ |
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486 when ther eare no more arguments available, or in a function that\n\ |
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487 has not been declared to take a variable number of parameters.\n\ |
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488 @end deftypefn") |
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489 { |
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490 octave_value_list retval; |
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491 |
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492 int nargin = args.length (); |
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493 |
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494 if (nargin == 0) |
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495 { |
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496 if (curr_function) |
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497 { |
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498 if (curr_function->takes_varargs ()) |
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499 retval = curr_function->octave_va_arg (); |
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500 else |
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501 { |
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502 ::error ("va_arg only valid within function taking variable"); |
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503 ::error ("number of arguments"); |
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504 } |
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505 } |
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506 else |
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507 ::error ("va_arg only valid within function body"); |
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508 } |
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509 else |
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510 print_usage ("va_arg"); |
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511 |
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512 return retval; |
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513 } |
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514 |
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515 DEFUN (va_start, args, , |
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516 "-*- texinfo -*-\n\ |
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517 @deftypefn {Built-in Function} {} va_start ()\n\ |
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518 Position an internal pointer to the first unnamed argument in\n\ |
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519 functions that have been declared to accept a variable number of\n\ |
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520 arguments. It is an error to call @code{va_start} in a function\n\ |
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521 that has not been declared to take a variable number of parameters.\n\ |
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522 @end deftypefn") |
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523 { |
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524 octave_value_list retval; |
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525 |
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526 int nargin = args.length (); |
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527 |
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528 if (nargin == 0) |
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529 { |
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530 if (curr_function) |
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531 { |
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532 if (curr_function->takes_varargs ()) |
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533 curr_function->octave_va_start (); |
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534 else |
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535 { |
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536 ::error ("va_start only valid within function taking variable"); |
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537 ::error ("number of arguments"); |
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538 } |
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539 } |
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540 else |
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541 ::error ("va_start only valid within function body"); |
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542 } |
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543 else |
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544 print_usage ("va_start"); |
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545 |
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546 return retval; |
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547 } |
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548 |
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549 DEFUN (vr_val, args, , |
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550 "-*- texinfo -*-\n\ |
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551 @deftypefn {Built-in Function} {} vr_val (@var{x})\n\ |
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552 Each time this function is called, it places the value of its argument\n\ |
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553 at the end of the list of values to return from the current\n\ |
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554 function. Once @code{vr_val} has been called, there is no way to go\n\ |
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555 back to the beginning of the list and rewrite any of the return\n\ |
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556 values. This function may only be called within functions that have\n\ |
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557 been declared to return an unspecified number of output arguments.\n\ |
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558 @end deftypefn") |
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559 { |
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560 octave_value_list retval; |
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561 |
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562 int nargin = args.length (); |
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563 |
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564 if (nargin == 1) |
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565 { |
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566 if (curr_function) |
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567 { |
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568 if (curr_function->takes_var_return ()) |
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569 curr_function->octave_vr_val (args(0)); |
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570 else |
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571 { |
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572 ::error ("vr_val only valid within function declared to"); |
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573 ::error ("produce a variable number of values"); |
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574 } |
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575 } |
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576 else |
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577 ::error ("vr_val only valid within function body"); |
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578 } |
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579 else |
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580 print_usage ("vr_val"); |
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581 |
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582 return retval; |
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583 } |
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584 |
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585 static int |
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586 define_all_return_values (void) |
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587 { |
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588 Vdefine_all_return_values = check_preference ("define_all_return_values"); |
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589 |
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590 return 0; |
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591 } |
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592 |
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593 static int |
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3131
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594 max_recursion_depth (void) |
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595 { |
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596 Vmax_recursion_depth = check_preference ("max_recursion_depth"); |
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597 |
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598 return 0; |
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599 } |
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600 |
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601 static int |
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602 return_last_computed_value (void) |
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603 { |
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604 Vreturn_last_computed_value |
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605 = check_preference ("return_last_computed_value"); |
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606 |
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607 return 0; |
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608 } |
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609 |
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610 void |
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611 symbols_of_ov_usr_fcn (void) |
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612 { |
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3258
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613 DEFVAR (default_return_value, Matrix (), 0, |
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3371
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614 "-*- texinfo -*-\n\ |
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615 @defvr {Built-in Variable} default_return_value\n\ |
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616 The value given to otherwise uninitialized return values if\n\ |
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617 @code{define_all_return_values} is nonzero. The default value is\n\ |
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618 @code{[]}.\n\ |
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619 @end defvr"); |
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620 |
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3258
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621 DEFVAR (define_all_return_values, 0.0, define_all_return_values, |
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3371
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622 "-*- texinfo -*-\n\ |
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623 @defvr {Built-in Variable} define_all_return_values\n\ |
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624 If the value of @code{define_all_return_values} is nonzero, Octave\n\ |
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625 will substitute the value specified by @code{default_return_value} for\n\ |
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626 any return values that remain undefined when a function returns. The\n\ |
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627 default value is 0.\n\ |
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628 @end defvr"); |
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629 |
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3258
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630 DEFVAR (max_recursion_depth, 256.0, max_recursion_depth, |
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3371
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631 "-*- texinfo -*-\n\ |
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632 @defvr {Built-in Variable} max_recursion_depth\n\ |
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633 Limit the number of times a function may be called recursively.\n\ |
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634 If the limit is exceeded, an error message is printed and control\n\ |
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635 returns to the top level.\n\ |
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636 \n\ |
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637 The default value is 256.\n\ |
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638 @end defvr"); |
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3131
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639 |
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3258
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640 DEFVAR (return_last_computed_value, 0.0, return_last_computed_value, |
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3371
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641 "-*- texinfo -*-\n\ |
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642 @defvr {Built-in Variable} return_last_computed_value\n\ |
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643 If the value of @code{return_last_computed_value} is true, and a\n\ |
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644 function is defined without explicitly specifying a return value, the\n\ |
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645 function will return the value of the last expression. Otherwise, no\n\ |
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646 value will be returned. The default value is 0.\n\ |
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647 \n\ |
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648 For example, the function\n\ |
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649 \n\ |
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650 @example\n\ |
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651 function f ()\n\ |
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652 2 + 2;\n\ |
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653 endfunction\n\ |
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654 @end example\n\ |
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655 \n\ |
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656 @noindent\n\ |
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657 will either return nothing, if the value of\n\ |
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658 @code{return_last_computed_value} is 0, or 4, if the value of\n\ |
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659 @code{return_last_computed_value} is nonzero.\n\ |
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660 @end defvr"); |
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2974
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661 } |
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662 |
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663 /* |
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664 ;;; Local Variables: *** |
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665 ;;; mode: C++ *** |
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666 ;;; End: *** |
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667 */ |
