Compare two character arrays while ignoring some characters.

Ignore some characters

Segment Element

Variable declaration

 992:   register int *ignore;

Segment Element

Code insertion

 998:       ignore = key->ignore;

Define CMP_WITH_IGNORE()

Macro definition

Notes

In an important interaction, CMP_WITH_IGNORE uses the data structures generated by LocaleOptz.

In a perverse implementation to support "readability" the CMP_WITH_IGNORE macro is embedded in the program text at the point of it's first usage. This divides the code that dispatches on the ignore flag.

Segment Source

1092: #define CMP_WITH_IGNORE(A, B)                                           \
1093:   do                                                                    \
1094:     {                                                                   \
1095:           while (texta < lima && textb < limb)                          \
1096:             {                                                           \
1097:               while (texta < lima && ignore[UCHAR (*texta)])            \
1098:                 ++texta;                                                \
1099:               while (textb < limb && ignore[UCHAR (*textb)])            \
1100:                 ++textb;                                                \
1101:               if (texta < lima && textb < limb)                         \
1102:                 {                                                       \
1103:                   if ((A) != (B))                                       \
1104:                     {                                                   \
1105:                       diff = (A) - (B);                                 \
1106:                       break;                                            \
1107:                     }                                                   \
1108:                   ++texta;                                              \
1109:                   ++textb;                                              \
1110:                 }                                                       \
1111:                                                                         \
1112:               if (texta == lima && textb < limb && !ignore[UCHAR (*textb)]) \
1113:                 diff = -1;                                              \
1114:               else if (texta < lima && textb == limb                    \
1115:                        && !ignore[UCHAR (*texta)])                      \
1116:                 diff = 1;                                               \
1117:             }                                                           \
1118:                                                                         \
1119:           if (diff == 0)                                                \
1120:             {                                                           \
1121:               while (texta < lima && ignore[UCHAR (*texta)])            \
1122:                 ++texta;                                                \
1123:               while (textb < limb && ignore[UCHAR (*textb)])            \
1124:                 ++textb;                                                \
1125:                                                                         \
1126:               if (texta == lima && textb < limb)                        \
1127:                 diff = -1;                                              \
1128:               else if (texta < lima && textb == limb)                   \
1129:                 diff = 1;                                               \
1130:             }                                                           \
1131:           /* Relative lengths are meaningless if characters were ignored.  \
1132:              Handling this case here avoids what might be an invalid length  \
1133:              comparison below.  */                                      \
1134:           if (diff == 0 && texta == lima && textb == limb)              \
1135:             return 0;                                                   \
1136:     }                                                                   \
1137:   while (0)
1138: