[Chapter 5] 5.21 PLVprs: String Parsing Chapter 5PL/Vision Package Specifications 5.21 PLVprs: String ParsingThe PLVprs (PL/Vision PaRSe) package offers a set of programs which provide generic and flexible string parsing capabilities. See Chapter 10, PLVprs, PLVtkn, and PLVprsps: Parsing Strings for details.5.21.1 Package constants c_ignore_case CONSTANT VARCHAR2(1) := 'I';c_respect_case CONSTANT VARCHAR2(1) := 'R';Use these constants to indicate whether you want case to be ignored or respected in the current operation. c_all CONSTANT VARCHAR(3) := 'ALL';c_word CONSTANT VARCHAR(4) := 'WORD';c_delim CONSTANT VARCHAR(5) := 'DELIM';The different types of atomics; c_all indicates "all atomics"; c_word indicates "words only"; c_delim indicates "delimiters only". std_delimiters CONSTANT VARCHAR2 (50) := '!@#$%^&*()-_=+\|`~{{]};:''",<.>/?' || PLVchr.newline_char || PLVchr.tab_char || PLVchr.space_char;The standard set of delimiter characters. plsql_delimiters CONSTANT VARCHAR2 (50) := '!@%^&*()-=+\|`~{{]};:''",<.>/?' || PLVchr.newline_char || PLVchr.tab_char || PLVchr.space_char;The set of delimiters for the PL/SQL language; this list is a bit different from the std_delimiters. The underscore and pound sign characters, for example, are not delimiters in PL/SQL.5.21.2 Wrapping long strings into paragraphs PROCEDURE wrap (text_in IN VARCHAR2, line_length IN INTEGER, paragraph_out IN OUT PLVtab.vc2000_table, num_lines_out IN OUT INTEGER);Wraps the string provided by text_in into separate lines with a maximum specified length, each line of which is stored in consecutive rows in a PL/SQL table. FUNCTION wrapped_string (text_in IN VARCHAR2, line_length IN INTEGER := 80, prefix_in IN VARCHAR2 := NULL)RETURN VARCHAR2;Returns a long string wrapped into a series of lines separated by newline characters. This version of wrap avoids the need to define and manipulate a PL/SQL table. PROCEDURE display_wrap (text_in IN VARCHAR2, line_length IN INTEGER := 80, prefix_in IN VARCHAR2 := NULL);Displays the wrapped version of text_in using the p.l procedure (and DBMS_OUTPUT.PUT_LINE).5.21.3 Analyzing string contents FUNCTION next_atom_loc (string_in IN VARCHAR2, start_loc_in IN NUMBER, direction_in IN NUMBER := +1, delimiters_in IN VARCHAR2 := std_delimiters)RETURN INTEGER; Returns the location in the string of the next atomic. You provide the starting location of the scan, the direction of the scan (usually +1 or -1, but you can provide other values as well), and the delimiters to be used in the scan. FUNCTION numatomics (string_in IN VARCHAR2, count_type_in IN VARCHAR2 := c_all, delimiters_in IN VARCHAR2 := std_delimiters)RETURN INTEGER;Returns the number of atomics in a string, where the definition of an atomic is provided by the count type (all or word or delimiter) and the set of delimiters. FUNCTION nth_atomic (string_in IN VARCHAR2, nth_in IN NUMBER, count_type_in IN VARCHAR2 := c_all, delimiters_in IN VARCHAR2 := std_delimiters)RETURN VARCHAR2;Returns the nth atomic in a string, where the definition of an atomic is provided by the count type (all or word or delimiter) and the set of delimiters.FUNCTION numinstr (string_in IN VARCHAR2, substring_in IN VARCHAR2, ignore_case_in IN VARCHAR2 := c_ignore_case)RETURN INTEGER;Returns the number of times a substring occurs in a string. You can choose to perform a search that is case-sensitive or that ignores case.5.21.4 Parsing strings PROCEDURE string (string_in IN VARCHAR2, atomics_list_out OUT PLVtab.vc2000_table, num_atomics_out IN OUT NUMBER, delimiters_in IN VARCHAR2 := std_delimiters);Parses a string into atomics that are loaded into a PL/SQL table. You decide which characters will serve as the delimiters. PROCEDURE string (string_in IN VARCHAR2, atomics_list_out IN OUT VARCHAR2, num_atomics_out IN OUT NUMBER, delimiters_in IN VARCHAR2 := std_delimiters);Parses a string into atomics stored in a string with each atomic separated by a vertical bar. Once again, you decide which characters will serve as the delimiters. PROCEDURE display_atomics (string_in IN VARCHAR2, delimiters_in IN VARCHAR2 := std_delimiters);Displays the individual atomics in a string, as defined by the provided list of delimiters.5.20 PLVobj: Object Interface5.22 PLVprsps: PL/SQL Source Code Parsing Copyright (c) 2000 O'Reilly & Associates. All rights reserved.