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2 | Program options post-review development plan. |
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3 | |
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4 | 0. Convert all documentation to BoostBook format |
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5 | |
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6 | 1. (done) |
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7 | Simplify and clarify interface. |
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8 | |
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9 | It turns out that most users are interested in 'variables_map' class, so |
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10 | it must be possible to use it directly, without even knowing about |
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11 | 'options_and_arguments'. The proposed interface is: |
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12 | |
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13 | options_description desc; |
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14 | .... |
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15 | variables_map vm; |
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16 | load_from_command_line(vm, desc, argc, argv); |
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17 | |
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18 | 2. (done) |
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19 | Better separation of syntaxic and semantic processing, as suggested by |
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20 | Pavol Droba. |
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21 | |
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22 | The problem with current 'option_description' interface is that the |
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23 | 'validator' and 'notifier' callbacks are not really usable by ordinary |
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24 | users --- it's extender's interface. The current 'parameter' function uses |
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25 | those callback to provide user-friendly semantic interface, but it's not |
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26 | documented nor completely worked out. |
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27 | |
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28 | In the new interface, the second parameter of 'option_description' ctor |
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29 | will have two possibilities: just a string and a pointer to a new class |
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30 | 'value_descriptor'. When passed the latter, it will invoke the instance on |
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31 | itself, and then delete the object. A function 'value' will be provided, |
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32 | that will create value specific for a type. |
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33 | |
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34 | Example |
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35 | ("magic", value<int>("n", &n)->default_value(10), "magic value"). |
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36 | |
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37 | The 'value' function will create instances of 'typed_value_descriptor' |
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38 | type, with the following methods: |
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39 | - default_value |
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40 | - interpreter |
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41 | - validator |
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42 | - notifier |
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43 | |
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44 | The 'option_description' class we'll have two attributes to support |
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45 | semantic operation: 'generator', which will handle conversion from string |
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46 | into value (including application of default value), and 'notifier'. Similiar |
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47 | to the the current design, those attributes will be set by |
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48 | 'value_descriptor' instances. |
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49 | |
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50 | Another function, "bool_switch" will create value descriptor for type bool, |
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51 | with default value of false. The function is needed to avoid special-casing |
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52 | 'value' function on bool type, which was considered confusing (Neal D. Becker). |
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53 | |
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54 | 3. (done) Support for positional options. |
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55 | |
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56 | Positional options will be treated uniformly with ordinary ones. User will |
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57 | be able to specify that, for example, third positional option is to be |
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58 | interpreted as option "output-file" with the same value. |
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59 | |
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60 | The user interface will be simple: user will provide two instanes of |
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61 | 'options_description' to functions which parse command line. For example. |
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62 | |
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63 | options_description desc; |
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64 | desc.add_options() |
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65 | ("magic", "n", "magic value") |
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66 | ; |
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67 | |
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68 | options_description pdesc; |
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69 | pdesc.add_options() |
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70 | ("output-file", "n", "output file") |
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71 | ("input-files*", value< vector<string> >("n"), "files") |
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72 | ; |
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73 | |
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74 | variables_map vm; |
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75 | load_from_command_line(vm, desc, pdesc, argc, argv); |
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76 | |
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77 | 4. (done, except for registry) |
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78 | Multiple sources improvement. |
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79 | |
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80 | Need to implement support for registry/environment. |
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81 | Also, must devise a way to handle different naming of option in |
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82 | sources. Lastly, the storing of values into program variables should |
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83 | become part of 'variables_map' interface. |
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84 | |
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85 | 5. Improve documentation. |
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86 | |
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87 | Chuck Messenger: |
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88 | "When code is given for an example program, after the code, give examples of |
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89 | using the program, along with the expected output." |
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90 | |
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91 | Pavol Droba: |
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92 | "I would prefer a few chapters explaining various components of the |
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93 | library, each followed by a reference." |
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94 | |
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95 | Pavel Vozenilek: |
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96 | > Documentation should contain list of compilers the library works on and |
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97 | > also info whether MSVC 6 port is feasible or not. |
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98 | > |
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99 | > The non-Doxygen part of documentation can be also a bit expanded: e.g. I |
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100 | > would welcome some high level overview of the algorithms and structures and |
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101 | > info about expected CPU/memory consumption. |
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102 | > |
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103 | > Also info whether there are any internal limits (like option length) . |
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104 | > |
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105 | > Some examples may be bit more annotated, also contain what is expected |
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106 | > output. |
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107 | |
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108 | Syntax highligting. |
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109 | |
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110 | Document "*" in option names |
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111 | Automated tests for examples? |
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112 | (new) Comments inside code snippets? |
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113 | (new) Table of all symbols |
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114 | |
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115 | |
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116 | 6. (deferred) |
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117 | Unicode support |
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118 | |
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119 | - unicode in argv/argc |
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120 | - Unicode in config files not supported |
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121 | ( |
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122 | The difference between ASCII and unicode files is: |
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123 | - big endian UTF16 starts with 2 bytes FE FF 9mandatory by Unicode |
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124 | standard) - little endian UTF16 starts with FF FE |
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125 | - UTF8 text starts with EF BB BF |
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126 | |
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127 | Pavel Vozenilek |
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128 | ) |
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129 | |
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130 | 7. Config file improvements |
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131 | |
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132 | - should have "allow_unregistered" for config_file. |
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133 | - (done) bool options in config file do not work. |
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134 | - "#" inside strings, in config files (Pavel Vozenilek) |
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135 | |
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136 | 8. |
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137 | Cmdline improvements |
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138 | |
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139 | - must be able to parse WinMain string |
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140 | - support for response files |
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141 | |
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142 | 9. Other changes. |
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143 | |
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144 | - (outdated) get_value -> value (Beman) |
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145 | - (done) is "argv" const in std, or not? Adjust docs if not. |
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146 | - variables_map::count_if, find_if (Tanton Gibbs) |
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147 | - Works with exceptions disabled. |
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148 | - (outdated) disallow empty name for the 'parameter' function |
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149 | - check for prefixes if 'allow_guessing' is on |
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150 | - check for duplicate declaration of options. |
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151 | - test additional parser |
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152 | - Show default values in help output |
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153 | - Adaptive field width |
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154 | - Mandatory options (2 votes (second Jonathan Graehl)) |
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155 | - (new) return vector from parsers by auto_ptr, not by value? |
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156 | - (new) rename value_semantic into value_description |
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157 | - (new) output for positional_options_description |
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158 | - (new) variables_map should throw when value not found |
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159 | - (important) decide where we check that the number of passed option |
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160 | tokens is less than the allowed number. In parser or later? |
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161 | - (important) what if the same option has different definitions? |
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162 | - (new) We lost the ability to specify options_description instance |
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163 | in call to 'store'. So now we can't store just subset of options. |
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164 | Is it a problem? |
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165 | - (new) Improve formatting of 'arg'. |
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166 | - (new) revive real and regexp examples. |
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167 | - (new) even more simpler syntax for assignent to var? |
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168 | |
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169 | |
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170 | 10. Uncertain |
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171 | - Function to get program name |
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172 | - Order of 'description' and 'value'. |
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173 | |
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174 | |
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175 | 11. (new) Look at all "TODO" comments. |
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176 | (new) Check that all methods are documented. |
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177 | |
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178 | |
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179 | 12. Deferred |
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180 | |
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181 | - storing value to boost::optional |
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182 | - setting a flag when option is found |
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