1 | /* Plural expression evaluation. |
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2 | Copyright (C) 2000-2002 Free Software Foundation, Inc. |
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3 | |
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4 | This program is free software; you can redistribute it and/or modify it |
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5 | under the terms of the GNU Library General Public License as published |
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6 | by the Free Software Foundation; either version 2, or (at your option) |
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7 | any later version. |
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8 | |
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9 | This program is distributed in the hope that it will be useful, |
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10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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12 | Library General Public License for more details. |
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13 | |
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14 | You should have received a copy of the GNU Library General Public |
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15 | License along with this program; if not, write to the Free Software |
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16 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, |
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17 | USA. */ |
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18 | |
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19 | #ifndef STATIC |
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20 | #define STATIC static |
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21 | #endif |
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22 | |
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23 | /* Evaluate the plural expression and return an index value. */ |
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24 | STATIC unsigned long int plural_eval PARAMS ((struct expression *pexp, |
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25 | unsigned long int n)) |
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26 | internal_function; |
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27 | |
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28 | STATIC |
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29 | unsigned long int |
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30 | internal_function |
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31 | plural_eval (pexp, n) |
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32 | struct expression *pexp; |
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33 | unsigned long int n; |
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34 | { |
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35 | switch (pexp->nargs) |
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36 | { |
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37 | case 0: |
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38 | switch (pexp->operation) |
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39 | { |
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40 | case var: |
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41 | return n; |
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42 | case num: |
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43 | return pexp->val.num; |
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44 | default: |
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45 | break; |
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46 | } |
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47 | /* NOTREACHED */ |
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48 | break; |
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49 | case 1: |
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50 | { |
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51 | /* pexp->operation must be lnot. */ |
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52 | unsigned long int arg = plural_eval (pexp->val.args[0], n); |
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53 | return ! arg; |
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54 | } |
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55 | case 2: |
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56 | { |
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57 | unsigned long int leftarg = plural_eval (pexp->val.args[0], n); |
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58 | if (pexp->operation == lor) |
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59 | return leftarg || plural_eval (pexp->val.args[1], n); |
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60 | else if (pexp->operation == land) |
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61 | return leftarg && plural_eval (pexp->val.args[1], n); |
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62 | else |
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63 | { |
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64 | unsigned long int rightarg = plural_eval (pexp->val.args[1], n); |
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65 | |
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66 | switch (pexp->operation) |
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67 | { |
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68 | case mult: |
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69 | return leftarg * rightarg; |
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70 | case divide: |
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71 | #if !INTDIV0_RAISES_SIGFPE |
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72 | if (rightarg == 0) |
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73 | raise (SIGFPE); |
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74 | #endif |
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75 | return leftarg / rightarg; |
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76 | case module: |
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77 | #if !INTDIV0_RAISES_SIGFPE |
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78 | if (rightarg == 0) |
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79 | raise (SIGFPE); |
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80 | #endif |
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81 | return leftarg % rightarg; |
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82 | case plus: |
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83 | return leftarg + rightarg; |
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84 | case minus: |
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85 | return leftarg - rightarg; |
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86 | case less_than: |
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87 | return leftarg < rightarg; |
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88 | case greater_than: |
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89 | return leftarg > rightarg; |
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90 | case less_or_equal: |
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91 | return leftarg <= rightarg; |
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92 | case greater_or_equal: |
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93 | return leftarg >= rightarg; |
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94 | case equal: |
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95 | return leftarg == rightarg; |
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96 | case not_equal: |
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97 | return leftarg != rightarg; |
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98 | default: |
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99 | break; |
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100 | } |
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101 | } |
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102 | /* NOTREACHED */ |
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103 | break; |
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104 | } |
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105 | case 3: |
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106 | { |
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107 | /* pexp->operation must be qmop. */ |
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108 | unsigned long int boolarg = plural_eval (pexp->val.args[0], n); |
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109 | return plural_eval (pexp->val.args[boolarg ? 1 : 2], n); |
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110 | } |
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111 | } |
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112 | /* NOTREACHED */ |
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113 | return 0; |
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114 | } |
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