3.1.5.5.1 CompareStringOrdinal Algorithm

This algorithm compares two UTF-16 strings by doing an ordinal (binary) comparison. Optionally, the caller can request that the comparison be done on the uppercase form of the string.

    COMMENT CompareStringOrdinal
    COMMENT  On Entry: StringA        – A UTF-16 string to be compared
    COMMENT  On Entry: StringB        – Second UTF-16 string to compare
    COMMENT  On Entry: IgnoreCaseFlag – TRUE to ignore case when comparing
    COMMENT
    COMMENT  On Exit:  Result – A value indicating if StringA is less than,
    COMMENT                     equal to, or greater than StringB
    
    PROCEDURE CompareStringOrdinal
    
    IF IgnoreCaseFlag is TRUE THEN
        SET StringA TO ToUpperCase(StringA)
        SET StringB TO ToUpperCase(StringB)
    ENDIF
    
    SET index TO 0
    
    WHILE index is less than Length(StringA) and
          index is also less than Length(StringB)
    
        IF StringA[index] is less than StringB[index] THEN
                  SET Result TO "StringA is less than StringB"
                  RETURN
        ENDIF
        IF StringA[index] is greater than StringB[index] THEN
                  SET Result TO "StringA is greater than StringB"
                  RETURN
        ENDIF
    INCREMENT index
    ENDWHILE
    
    IF Length(StringA) is equal to Length(StringB) THEN
        SET Result TO "StringA is equal to StringB" 
 ELSE IF Length(StringA) is less than Length(StringB) THEN
           SET Result TO "StringA is less than StringB"
    ELSE
        Assert Length(StringA) has to be greater than Length(StringB)
        SET Result TO "StringA is greater than StringB"
    ENDIF
    RETURN