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1 " |
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2 COPYRIGHT (c) 1988-93 by Claus Gittinger |
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3 All Rights Reserved |
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4 |
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5 This software is furnished under a license and may be used |
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6 only in accordance with the terms of that license and with the |
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7 inclusion of the above copyright notice. This software may not |
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8 be provided or otherwise made available to, or used by, any |
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9 other person. No title to or ownership of the software is |
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10 hereby transferred. |
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11 " |
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12 |
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13 String subclass:#Symbol |
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14 instanceVariableNames:'' |
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15 classVariableNames:'' |
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16 poolDictionaries:'' |
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17 category:'Collections-Text' |
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18 ! |
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19 |
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20 Symbol comment:' |
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21 |
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22 COPYRIGHT (c) 1988-93 by Claus Gittinger |
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23 All Rights Reserved |
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24 |
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25 Symbols represent unique strings - every symbol with same printString |
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26 exists exactly once in the system; Symbols are used for selectors, global |
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27 variable-keys etc. |
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28 |
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29 %W% %E% |
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30 '! |
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31 |
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32 !Symbol class methodsFor:'instance creation'! |
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33 |
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34 basicNew:size |
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35 "catch instance creation - symbols are not created with new" |
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36 |
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37 self error:'symbols may not be created with new:' |
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38 ! |
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39 |
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40 intern:aString |
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41 "return a unique symbol with printname taken from the String-argument" |
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42 |
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43 %{ |
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44 if (_isString(aString)) { |
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45 RETURN ( _MKSYMBOL(_stringVal(aString), (OBJ *)0, __context) ); |
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46 } |
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47 %} |
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48 . |
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49 ^ self mustBeString |
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50 ! |
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51 |
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52 internCharacter:aCharacter |
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53 "return a unique symbol with printname taken from the Character-argument" |
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54 |
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55 ^ self intern:(aCharacter asString) |
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56 ! ! |
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57 |
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58 !Symbol class methodsFor:'queries'! |
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59 |
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60 hasInterned:aString ifTrue:trueBlock |
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61 "for ST-80 compatibility - if the argument, aString is known |
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62 as Symbol, evaluate the block with the corresponding symbol |
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63 as argument and return true; otherwise return false" |
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64 |
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65 aString knownAsSymbol ifTrue:[ |
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66 trueBlock value:(aString asSymbol). |
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67 ^ true |
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68 ]. |
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69 ^ false |
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70 ! ! |
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71 |
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72 !Symbol methodsFor:'accessing'! |
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73 |
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74 basicAt:index put:something |
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75 "report an error - symbols may not be changed" |
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76 |
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77 self error:'symbols may not be changed' |
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78 ! |
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79 |
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80 at:index put:something |
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81 "report an error - symbols may not be changed" |
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82 |
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83 self error:'symbols may not be changed' |
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84 ! ! |
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85 |
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86 !Symbol methodsFor:'copying'! |
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87 |
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88 deepCopy |
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89 "return a copy of myself |
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90 - reimplemented here since symbols are unique" |
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91 |
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92 ^ self |
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93 ! ! |
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94 |
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95 !Symbol methodsFor:'converting'! |
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96 |
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97 asString |
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98 "return a string with printname taken from mine" |
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99 |
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100 ^ self printString |
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101 ! |
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102 |
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103 asSymbol |
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104 "I am a symbol - just return myself" |
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105 |
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106 ^ self |
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107 ! ! |
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108 |
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109 !Symbol methodsFor:'misc'! |
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110 |
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111 species |
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112 ^ String |
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113 ! |
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114 |
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115 nArgsIfSelector |
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116 "if symbol is used as a selector, how many arguments would it take" |
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117 |
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118 |binopChars| |
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119 |
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120 (self size > 2) ifFalse:[ |
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121 binopChars := '|&-+=*/\<>~@,'. |
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122 (self size == 1) ifTrue:[ |
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123 ((binopChars occurrencesOf:(self at:1)) == 0) ifTrue:[^ 0]. |
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124 ^ 1 |
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125 ]. |
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126 ((binopChars occurrencesOf:(self at:1)) == 0) ifFalse:[ |
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127 ((binopChars occurrencesOf:(self at:2)) == 0) ifFalse:[^ 1] |
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128 ] |
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129 ]. |
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130 ^ self occurrencesOf:$: |
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131 ! ! |
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132 |
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133 !Symbol methodsFor:'printing & storing'! |
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134 |
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135 printString |
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136 %{ |
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137 RETURN ( _MKSTRING(_stringVal(self) COMMA_CON) ); |
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138 %} |
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139 ! |
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140 |
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141 printOn:aStream |
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142 "aStream nextPut:$#." |
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143 aStream nextPutAll:(self printString) |
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144 ! |
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145 |
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146 displayString |
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147 ^ self storeString |
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148 ! |
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149 |
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150 storeString |
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151 "return a String for storing myself" |
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152 |
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153 ^ $# asString , self |
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154 ! |
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155 |
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156 storeOn:aStream |
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157 aStream nextPut:$#. |
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158 aStream nextPutAll:(self printString) |
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159 ! ! |