Add three new regexp functions: regexp_matches, regexp_split_to_array,

and regexp_split_to_table. These functions provide access to the
capture groups resulting from a POSIX regular expression match,
and provide the ability to split a string on a POSIX regular
expression, respectively. Patch from Jeremy Drake; code review by
Neil Conway, additional comments and suggestions from Tom and
Peter E.

This patch bumps the catversion, adds some regression tests,
and updates the docs.

7 files changed, 1001 insertions, 70 deletions

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index b8be507f2df..084db0d40e5 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.369 2007/02/20 19:59:04 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.370 2007/03/20 05:44:59 neilc Exp $ -->
 
  <chapter id="functions">
   <title>Functions and Operators</title>
@@ -1468,18 +1468,53 @@
       </row>
 
       <row>
-       <entry><literal><function>regexp_replace</function>(<parameter>string</parameter> <type>text</type>, <parameter>pattern</parameter> <type>text</type>, <parameter>replacement</parameter> <type>text</type> [,<parameter>flags</parameter> <type>text</type>])</literal></entry>
+       <entry><literal><function>regexp_matches</function>(<parameter>string</parameter> <type>text</type>, <parameter>pattern</parameter> <type>text</type> [, <parameter>flags</parameter> <type>text</type>])</literal></entry>
+       <entry><type>setof text[]</type></entry>
+       <entry>
+        Return all capture groups resulting from matching POSIX regular
+        expression against the <parameter>string</parameter>. See
+        <xref linkend="functions-posix-regexp"> for more information.
+       </entry>
+       <entry><literal>regexp_matches('foobarbequebaz', '(bar)(beque)')</literal></entry>
+       <entry><literal>{bar,beque}</literal></entry>
+      </row>
+
+      <row>
+       <entry><literal><function>regexp_replace</function>(<parameter>string</parameter> <type>text</type>, <parameter>pattern</parameter> <type>text</type>, <parameter>replacement</parameter> <type>text</type> [, <parameter>flags</parameter> <type>text</type>])</literal></entry>
        <entry><type>text</type></entry>
        <entry>
         Replace substring matching POSIX regular expression. See
-        <xref linkend="functions-matching"> for more information on pattern
-        matching.
+        <xref linkend="functions-posix-regexp"> for more information.
        </entry>
        <entry><literal>regexp_replace('Thomas', '.[mN]a.', 'M')</literal></entry>
        <entry><literal>ThM</literal></entry>
       </row>
 
       <row>
+       <entry><literal><function>regexp_split_to_array</function>(<parameter>string</parameter> <type>text</type>, <parameter>pattern</parameter> <type>text</type> [, <parameter>flags</parameter> <type>text</type> ])</literal></entry>
+       <entry><type>text[]</type></entry>
+       <entry>
+        Split <parameter>string</parameter> using POSIX regular expression as
+        the delimiter.  See <xref linkend="functions-posix-regexp"> for more
+        information.
+       </entry>
+       <entry><literal>regexp_split_to_array('hello world', E'\\s+')</literal></entry>
+       <entry><literal>{hello,world}</literal></entry>
+      </row>
+
+      <row>
+       <entry><literal><function>regexp_split_to_table</function>(<parameter>string</parameter> <type>text</type>, <parameter>pattern</parameter> <type>text</type> [, <parameter>flags</parameter> <type>text</type>])</literal></entry>
+       <entry><type>setof text</type></entry>
+       <entry>
+        Split <parameter>string</parameter> using POSIX regular expression as
+        the delimiter.  See <xref linkend="functions-posix-regexp"> for more
+        information.
+       </entry>
+       <entry><literal>regexp_split_to_table('hello world', E'\\s+')</literal></entry>
+       <entry><literal>hello</literal><para><literal>world</literal></para> (2 rows)</entry>
+      </row>
+
+      <row>
        <entry><literal><function>repeat</function>(<parameter>string</parameter> <type>text</type>, <parameter>number</parameter> <type>int</type>)</literal></entry>
        <entry><type>text</type></entry>
        <entry>Repeat <parameter>string</parameter> the specified
@@ -2883,9 +2918,6 @@ cast(-44 as bit(12))           <lineannotation>111111010100</lineannotation>
    <indexterm>
     <primary>substring</primary>
    </indexterm>
-   <indexterm>
-    <primary>regexp_replace</primary>
-   </indexterm>
 
 <synopsis>
 <replaceable>string</replaceable> SIMILAR TO <replaceable>pattern</replaceable> <optional>ESCAPE <replaceable>escape-character</replaceable></optional>
@@ -3004,6 +3036,21 @@ substring('foobar' from '#"o_b#"%' for '#')    <lineannotation>NULL</lineannotat
     <primary>regular expression</primary>
     <seealso>pattern matching</seealso>
    </indexterm>
+   <indexterm>
+    <primary>substring</primary>
+   </indexterm>
+   <indexterm>
+    <primary>regexp_replace</primary>
+   </indexterm>
+   <indexterm>
+    <primary>regexp_matches</primary>
+   </indexterm>
+   <indexterm>
+    <primary>regexp_split_to_table</primary>
+   </indexterm>
+   <indexterm>
+    <primary>regexp_split_to_array</primary>
+   </indexterm>
 
    <para>
     <xref linkend="functions-posix-table"> lists the available
@@ -3134,7 +3181,10 @@ substring('foobar' from 'o(.)b')   <lineannotation>o</lineannotation>
      string containing zero or more single-letter flags that change the
      function's behavior.  Flag <literal>i</> specifies case-insensitive
      matching, while flag <literal>g</> specifies replacement of each matching
-     substring rather than only the first one.
+     substring rather than only the first one.  Other supported flags are
+     <literal>m</>, <literal>n</>, <literal>p</>, <literal>w</> and
+     <literal>x</>, whose meanings correspond to those shown in
+     <xref linkend="posix-embedded-options-table">.
     </para>
 
    <para>
@@ -3149,6 +3199,124 @@ regexp_replace('foobarbaz', 'b(..)', E'X\\1Y', 'g')
 </programlisting>
    </para>
 
+    <para>
+     The <function>regexp_matches</> function returns all of the capture
+     groups resulting from matching a POSIX regular expression pattern.
+     It has the syntax
+     <function>regexp_matches</function>(<replaceable>string</>, <replaceable>pattern</>
+     <optional>, <replaceable>flags</> </optional>).
+     If there is no match to the <replaceable>pattern</>, the function returns no rows.
+     If there is a match, the function returns the contents of all of the capture groups
+     in a text array, or if there were no capture groups in the pattern, it returns the
+     contents of the entire match as a single-element text array.
+     The <replaceable>flags</> parameter is an optional text
+     string containing zero or more single-letter flags that change the
+     function's behavior.  Flag <literal>i</> specifies case-insensitive
+     matching, while flag <literal>g</> causes the return of each matching
+     substring rather than only the first one.  Other supported
+     flags are <literal>m</>, <literal>n</>, <literal>p</>, <literal>w</> and
+     <literal>x</>, whose meanings are described in
+     <xref linkend="posix-embedded-options-table">.
+    </para>
+
+   <para>
+    Some examples:
+<programlisting>
+SELECT regexp_matches('foobarbequebaz', '(bar)(beque)');
+ regexp_matches 
+----------------
+ {bar,beque}
+(1 row)
+
+SELECT regexp_matches('foobarbequebazilbarfbonk', '(b[^b]+)(b[^b]+)', 'g');
+ regexp_matches 
+----------------
+ {bar,beque}
+ {bazil,barf}
+(2 rows)
+
+SELECT regexp_matches('foobarbequebaz', 'barbeque');
+ regexp_matches 
+----------------
+ {barbeque}
+(1 row)
+</programlisting>
+   </para>
+
+    <para>
+     The <function>regexp_split_to_table</> function splits a string using a POSIX
+     regular expression pattern as a delimiter.  It has the syntax
+     <function>regexp_split_to_table</function>(<replaceable>string</>, <replaceable>pattern</>
+     <optional>, <replaceable>flags</> </optional>).
+     If there is no match to the <replaceable>pattern</>, the function returns the
+     <replaceable>string</>.  If there is at least one match, for each match it returns
+     the text from the end of the last match (or the beginning of the string)
+     to the beginning of the match.  When there are no more matches, it
+     returns the text from the end of the last match to the end of the string.
+     The <replaceable>flags</> parameter is an optional text string containing
+     zero or more single-letter flags that change the function's behavior.
+     <function>regexp_split_to_table</function> supports the flags <literal>i</>,
+     <literal>m</>, <literal>n</>, <literal>p</>, <literal>w</> and
+     <literal>x</>, whose meanings are described in
+     <xref linkend="posix-embedded-options-table">.
+    </para>
+
+    <para>
+     The <function>regexp_split_to_array</> function behaves the same as
+     <function>regexp_split_to_table</>, except that <function>regexp_split_to_array</>
+     returns its results as a <type>text[]</>.  It has the syntax
+     <function>regexp_split_to_array</function>(<replaceable>string</>, <replaceable>pattern</>
+     <optional>, <replaceable>flags</> </optional>).
+     The parameters are the same as for <function>regexp_split_to_table</>.
+    </para>
+
+   <para>
+    Some examples:
+<programlisting>
+
+SELECT foo FROM regexp_split_to_table('the quick brown fox jumped over the lazy dog', E'\\\s+') AS foo;
+  foo   
+--------
+ the    
+ quick  
+ brown  
+ fox    
+ jumped 
+ over   
+ the    
+ lazy   
+ dog    
+(9 rows)
+
+SELECT regexp_split_to_array('the quick brown fox jumped over the lazy dog', E'\\s+');
+              regexp_split_to_array             
+------------------------------------------------
+ {the,quick,brown,fox,jumped,over,the,lazy,dog}
+(1 row)
+
+SELECT foo FROM regexp_split_to_table('the quick brown fox', E'\\s*') AS foo;
+ foo 
+-----
+ t         
+ h         
+ e         
+ q         
+ u         
+ i         
+ c         
+ k         
+ b         
+ r         
+ o         
+ w         
+ n         
+ f         
+ o         
+ x         
+(16 rows)
+</programlisting>
+   </para>
+
    <para>
     <productname>PostgreSQL</productname>'s regular expressions are implemented
     using a package written by Henry Spencer.  Much of
diff --git a/src/backend/utils/adt/regexp.c b/src/backend/utils/adt/regexp.c
index 6a7a5fcc13b..9f8dd0323a9 100644
--- a/src/backend/utils/adt/regexp.c
+++ b/src/backend/utils/adt/regexp.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/regexp.c,v 1.69 2007/02/27 23:48:08 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/regexp.c,v 1.70 2007/03/20 05:44:59 neilc Exp $
  *
  *		Alistair Crooks added the code for the regex caching
  *		agc - cached the regular expressions used - there's a good chance
@@ -29,9 +29,12 @@
  */
 #include "postgres.h"
 
+#include "access/heapam.h"
+#include "funcapi.h"
 #include "regex/regex.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
+#include "utils/lsyscache.h"
 
 
 /* GUC-settable flavor parameter */
@@ -75,9 +78,56 @@ typedef struct cached_re_str
 	regex_t		cre_re;			/* the compiled regular expression */
 } cached_re_str;
 
+typedef struct re_comp_flags
+{
+	int			  cflags;
+	bool		  glob;
+} re_comp_flags;
+
+typedef struct regexp_matches_ctx
+{
+	text		 *orig_str;
+	size_t		  orig_len;
+	pg_wchar	 *wide_str;
+	size_t		  wide_len;
+	regex_t		 *cpattern;
+	regmatch_t	 *pmatch;
+	size_t		  offset;
+
+	re_comp_flags flags;
+
+	/* text type info */
+	Oid			  param_type;
+	int16		  typlen;
+	bool		  typbyval;
+	char		  typalign;
+} regexp_matches_ctx;
+
+typedef struct regexp_split_ctx
+{
+	text		 *orig_str;
+	size_t		  orig_len;
+	pg_wchar	 *wide_str;
+	size_t		  wide_len;
+	regex_t		 *cpattern;
+	regmatch_t	  match;
+	size_t		  offset;
+	re_comp_flags flags;
+} regexp_split_ctx;
+
+
 static int	num_res = 0;		/* # of cached re's */
 static cached_re_str re_array[MAX_CACHED_RES];	/* cached re's */
 
+static regexp_matches_ctx *setup_regexp_matches(FunctionCallInfo fcinfo,
+												text *orig_str, text *pattern,
+												text *flags);
+static ArrayType *perform_regexp_matches(regexp_matches_ctx *matchctx);
+
+static regexp_split_ctx *setup_regexp_split(text *str, text *pattern,
+											text *flags);
+static Datum get_next_split(regexp_split_ctx *splitctx);
+
 
 /*
  * RE_compile_and_cache - compile a RE, caching if possible
@@ -88,7 +138,7 @@ static cached_re_str re_array[MAX_CACHED_RES];	/* cached re's */
  *	cflags --- compile options for the pattern
  *
  * Pattern is given in the database encoding.  We internally convert to
- * array of pg_wchar which is what Spencer's regex package wants.
+ * an array of pg_wchar, which is what Spencer's regex package wants.
  */
 static regex_t *
 RE_compile_and_cache(text *text_re, int cflags)
@@ -191,48 +241,36 @@ RE_compile_and_cache(text *text_re, int cflags)
 }
 
 /*
- * RE_compile_and_execute - compile and execute a RE
+ * RE_wchar_execute - execute a RE
  *
  * Returns TRUE on match, FALSE on no match
  *
- *	text_re --- the pattern, expressed as an *untoasted* TEXT object
- *	dat --- the data to match against (need not be null-terminated)
- *	dat_len --- the length of the data string
- *	cflags --- compile options for the pattern
+ *	re --- the compiled pattern as returned by RE_compile_and_cache
+ *	data --- the data to match against (need not be null-terminated)
+ *	data_len --- the length of the data string
+ *	start_search -- the offset in the data to start searching
  *	nmatch, pmatch	--- optional return area for match details
  *
- * Both pattern and data are given in the database encoding.  We internally
- * convert to array of pg_wchar which is what Spencer's regex package wants.
+ * Data is given as array of pg_wchar which is what Spencer's regex package
+ * wants.
  */
 static bool
-RE_compile_and_execute(text *text_re, char *dat, int dat_len,
-					   int cflags, int nmatch, regmatch_t *pmatch)
+RE_wchar_execute(regex_t *re, pg_wchar *data, int data_len,
+				 size_t start_search, int nmatch, regmatch_t *pmatch)
 {
-	pg_wchar   *data;
-	size_t		data_len;
 	int			regexec_result;
-	regex_t    *re;
 	char		errMsg[100];
 
-	/* Convert data string to wide characters */
-	data = (pg_wchar *) palloc((dat_len + 1) * sizeof(pg_wchar));
-	data_len = pg_mb2wchar_with_len(dat, data, dat_len);
-
-	/* Compile RE */
-	re = RE_compile_and_cache(text_re, cflags);
-
 	/* Perform RE match and return result */
 	regexec_result = pg_regexec(re,
 								data,
 								data_len,
-								0,
+								start_search,
 								NULL,	/* no details */
 								nmatch,
 								pmatch,
 								0);
 
-	pfree(data);
-
 	if (regexec_result != REG_OKAY && regexec_result != REG_NOMATCH)
 	{
 		/* re failed??? */
@@ -245,13 +283,116 @@ RE_compile_and_execute(text *text_re, char *dat, int dat_len,
 	return (regexec_result == REG_OKAY);
 }
 
+/*
+ * RE_execute - execute a RE
+ *
+ * Returns TRUE on match, FALSE on no match
+ *
+ *	re --- the compiled pattern as returned by RE_compile_and_cache
+ *	dat --- the data to match against (need not be null-terminated)
+ *	dat_len --- the length of the data string
+ *	nmatch, pmatch	--- optional return area for match details
+ *
+ * Data is given in the database encoding.  We internally
+ * convert to array of pg_wchar which is what Spencer's regex package wants.
+ */
+static bool
+RE_execute(regex_t *re, char *dat, int dat_len,
+		   int nmatch, regmatch_t *pmatch)
+{
+	pg_wchar   *data;
+	size_t		data_len;
+	bool		match;
+
+	/* Convert data string to wide characters */
+	data = (pg_wchar *) palloc((dat_len + 1) * sizeof(pg_wchar));
+	data_len = pg_mb2wchar_with_len(dat, data, dat_len);
+
+	/* Perform RE match and return result */
+	match = RE_wchar_execute(re, data, data_len, 0, nmatch, pmatch);
+	pfree(data);
+	return match;
+}
+
+/*
+ * RE_compile_and_execute - compile and execute a RE
+ *
+ * Returns TRUE on match, FALSE on no match
+ *
+ *	text_re --- the pattern, expressed as an *untoasted* TEXT object
+ *	dat --- the data to match against (need not be null-terminated)
+ *	dat_len --- the length of the data string
+ *	cflags --- compile options for the pattern
+ *	nmatch, pmatch	--- optional return area for match details
+ *
+ * Both pattern and data are given in the database encoding.  We internally
+ * convert to array of pg_wchar which is what Spencer's regex package wants.
+ */
+static bool
+RE_compile_and_execute(text *text_re, char *dat, int dat_len,
+					   int cflags, int nmatch, regmatch_t *pmatch)
+{
+	regex_t    *re;
+
+	/* Compile RE */
+	re = RE_compile_and_cache(text_re, cflags);
+
+	return RE_execute(re, dat, dat_len, nmatch, pmatch);
+}
+
+static void
+parse_re_comp_flags(re_comp_flags *flags, text *opts)
+{
+	MemSet(flags, 0, sizeof(re_comp_flags));
+	flags->cflags = regex_flavor;
+
+	if (opts)
+	{
+		char  *opt_p = VARDATA(opts);
+		size_t opt_len = VARSIZE(opts) - VARHDRSZ;
+		int i;
+
+		for (i = 0; i < opt_len; i++)
+		{
+			switch (opt_p[i])
+			{
+				case 'g':
+					flags->glob = true;
+					break;
+				case 'i':
+					flags->cflags |= REG_ICASE;
+					break;
+				case 'm':
+				case 'n':
+					flags->cflags |= REG_NEWLINE;
+					break;
+				case 'p':
+					flags->cflags |= REG_NLSTOP;
+					flags->cflags &= ~REG_NLANCH;
+					break;
+				case 'w':
+					flags->cflags &= ~REG_NLSTOP;
+					flags->cflags |= REG_NLANCH;
+					break;
+				case 'x':
+					flags->cflags |= REG_EXPANDED;
+					break;
+				default:
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+							 errmsg("invalid regexp option: %c", opt_p[i])));
+					break;
+			}
+		}
+	}
+}
+
 
 /*
  * assign_regex_flavor - GUC hook to validate and set REGEX_FLAVOR
  */
 const char *
-assign_regex_flavor(const char *value,
-					bool doit, GucSource source)
+assign_regex_flavor(const char *value, bool doit, GucSource source)
 {
 	if (pg_strcasecmp(value, "advanced") == 0)
 	{
@@ -469,39 +610,14 @@ textregexreplace(PG_FUNCTION_ARGS)
 	text	   *p = PG_GETARG_TEXT_P(1);
 	text	   *r = PG_GETARG_TEXT_P(2);
 	text	   *opt = PG_GETARG_TEXT_P(3);
-	char	   *opt_p = VARDATA(opt);
-	int			opt_len = (VARSIZE(opt) - VARHDRSZ);
-	int			i;
-	bool		glob = false;
-	bool		ignorecase = false;
 	regex_t    *re;
+	re_comp_flags flags;
 
-	/* parse options */
-	for (i = 0; i < opt_len; i++)
-	{
-		switch (opt_p[i])
-		{
-			case 'i':
-				ignorecase = true;
-				break;
-			case 'g':
-				glob = true;
-				break;
-			default:
-				ereport(ERROR,
-						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-						 errmsg("invalid option of regexp_replace: %c",
-								opt_p[i])));
-				break;
-		}
-	}
+	parse_re_comp_flags(&flags, opt);
 
-	if (ignorecase)
-		re = RE_compile_and_cache(p, regex_flavor | REG_ICASE);
-	else
-		re = RE_compile_and_cache(p, regex_flavor);
+	re = RE_compile_and_cache(p, flags.cflags);
 
-	PG_RETURN_TEXT_P(replace_text_regexp(s, (void *) re, r, glob));
+	PG_RETURN_TEXT_P(replace_text_regexp(s, (void *) re, r, flags.glob));
 }
 
 /* similar_escape()
@@ -625,6 +741,361 @@ similar_escape(PG_FUNCTION_ARGS)
 	PG_RETURN_TEXT_P(result);
 }
 
+#define PG_GETARG_TEXT_P_IF_EXISTS(_n) \
+	(PG_NARGS() > _n ? PG_GETARG_TEXT_P(_n) : NULL)
+
+Datum
+regexp_matches(PG_FUNCTION_ARGS)
+{
+	FuncCallContext		*funcctx;
+	MemoryContext		 oldcontext;
+	regexp_matches_ctx	*matchctx;
+
+	if (SRF_IS_FIRSTCALL())
+	{
+		text *pattern = PG_GETARG_TEXT_P(1);
+		text *flags   = PG_GETARG_TEXT_P_IF_EXISTS(2);
+
+		funcctx = SRF_FIRSTCALL_INIT();
+		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+		/* be sure to copy the input string into the multi-call ctx */
+		matchctx = setup_regexp_matches(fcinfo, PG_GETARG_TEXT_P_COPY(0),
+										pattern, flags);
+
+		MemoryContextSwitchTo(oldcontext);
+		funcctx->user_fctx = (void *) matchctx;
+
+		/*
+		 * Avoid run-away function by making sure we never iterate
+		 * more than the length of the text + 1 (the number of matches
+		 * an empty pattern will make is length + 1)
+		 */
+		if (matchctx->flags.glob)
+			funcctx->max_calls = matchctx->wide_len + 1;
+		else
+			funcctx->max_calls = 0;
+	}
+
+	funcctx = SRF_PERCALL_SETUP();
+	matchctx = (regexp_matches_ctx *) funcctx->user_fctx;
+
+	if (funcctx->call_cntr > funcctx->max_calls)
+	{
+		/*
+		 * If max_calls == 0, then we are doing a non-global match, we
+		 * should stop now, no problem.  Otherwise, if we exceed
+		 * max_calls something really wonky is going on, since it is
+		 * returning more matches than there are characters in the
+		 * string, which should not happen
+		 */
+		if (funcctx->max_calls != 0)
+			elog(ERROR, "set returning match function terminated after iterating %d times",
+				 funcctx->call_cntr);
+
+		SRF_RETURN_DONE(funcctx);
+	}
+
+	if (matchctx->offset < matchctx->wide_len)
+	{
+		ArrayType *result_ary;
+
+		if (matchctx->pmatch[0].rm_so == matchctx->pmatch[0].rm_eo)
+			matchctx->offset++;
+
+		result_ary = perform_regexp_matches(matchctx);
+		if (result_ary != NULL)
+		{
+			matchctx->offset = matchctx->pmatch[0].rm_eo;
+			SRF_RETURN_NEXT(funcctx, PointerGetDatum(result_ary));
+		}
+		/* else fall through and return done */
+	}
+
+	SRF_RETURN_DONE(funcctx);
+}
+
+Datum
+regexp_matches_no_flags(PG_FUNCTION_ARGS)
+{
+	return regexp_matches(fcinfo);
+}
+
+static regexp_matches_ctx *
+setup_regexp_matches(FunctionCallInfo fcinfo, text *orig_str, text *pattern, text *flags)
+{
+	regexp_matches_ctx	*matchctx = palloc(sizeof(regexp_matches_ctx));
+
+	matchctx->orig_str = orig_str;
+	matchctx->orig_len = VARSIZE(matchctx->orig_str) - VARHDRSZ;
+
+	parse_re_comp_flags(&matchctx->flags, flags);
+
+	matchctx->cpattern = RE_compile_and_cache(pattern, matchctx->flags.cflags);
+	matchctx->pmatch = palloc(sizeof(regmatch_t) * (matchctx->cpattern->re_nsub + 1));
+	matchctx->offset = 0;
+
+	/* get text type oid, too lazy to do it some other way */
+	matchctx->param_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
+	get_typlenbyvalalign(matchctx->param_type, &matchctx->typlen,
+						 &matchctx->typbyval, &matchctx->typalign);
+
+	matchctx->wide_str = palloc(sizeof(pg_wchar) * (matchctx->orig_len + 1));
+	matchctx->wide_len = pg_mb2wchar_with_len(VARDATA(matchctx->orig_str),
+											  matchctx->wide_str, matchctx->orig_len);
+
+	matchctx->pmatch[0].rm_so = -1;
+	/* both < 0 but not equal */
+	matchctx->pmatch[0].rm_eo = -2;
+
+	return matchctx;
+}
+
+static ArrayType *
+perform_regexp_matches(regexp_matches_ctx *matchctx)
+{
+	Datum 		*elems;
+	bool 		*nulls;
+	Datum 		 fullmatch;		/* used to avoid a palloc if no matches */
+	int 		 ndims = 1;
+	int 		 dims[1];
+	int          lbs[1] = {1};
+
+	if (RE_wchar_execute(matchctx->cpattern,
+						 matchctx->wide_str,
+						 matchctx->wide_len,
+						 matchctx->offset,
+						 matchctx->cpattern->re_nsub + 1,
+						 matchctx->pmatch) == false)
+		return NULL;
+
+	if (matchctx->cpattern->re_nsub > 0)
+	{
+		int i;
+
+		elems = palloc(sizeof(Datum) * matchctx->cpattern->re_nsub);
+		nulls = palloc(sizeof(bool) * matchctx->cpattern->re_nsub);
+		dims[0] = matchctx->cpattern->re_nsub;
+
+		for (i = 0; i < matchctx->cpattern->re_nsub; i++)
+		{
+			int so = matchctx->pmatch[i + 1].rm_so;
+			int	eo = matchctx->pmatch[i + 1].rm_eo;
+
+			if (so < 0 || eo < 0)
+			{
+				elems[i] = 0;
+				nulls[i] = true;
+			}
+			else
+			{
+				elems[i] = DirectFunctionCall3(text_substr,
+											   PointerGetDatum(matchctx->orig_str),
+											   Int32GetDatum(so + 1),
+											   Int32GetDatum(eo - so));
+				nulls[i] = false;
+			}
+		}
+	}
+	else
+	{
+		int so = matchctx->pmatch[0].rm_so;
+		int	eo = matchctx->pmatch[0].rm_eo;
+
+		if (so < 0 || eo < 0)
+			elog(ERROR, "regexp code said it had a match, but did not return it");
+
+		fullmatch = DirectFunctionCall3(text_substr,
+										PointerGetDatum(matchctx->orig_str),
+										Int32GetDatum(so + 1),
+										Int32GetDatum(eo - so));
+
+		elems = &fullmatch;
+		nulls = NULL;
+		dims[0] = 1;
+	}
+
+	return construct_md_array(elems, nulls, ndims, dims, lbs,
+							  matchctx->param_type, matchctx->typlen,
+							  matchctx->typbyval, matchctx->typalign);
+}
+
+Datum
+regexp_split_to_table(PG_FUNCTION_ARGS)
+{
+	FuncCallContext  *funcctx;
+	regexp_split_ctx *splitctx;
+
+	if (SRF_IS_FIRSTCALL())
+	{
+		text 			*pattern = PG_GETARG_TEXT_P(1);
+		text 			*flags   = PG_GETARG_TEXT_P_IF_EXISTS(2);
+		MemoryContext    oldcontext;
+
+		funcctx = SRF_FIRSTCALL_INIT();
+		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+		splitctx = setup_regexp_split(PG_GETARG_TEXT_P_COPY(0), pattern, flags);
+
+		MemoryContextSwitchTo(oldcontext);
+		funcctx->user_fctx = (void *) splitctx;
+
+		/*
+		 * Avoid run-away function by making sure we never iterate
+		 * more than the length of the text
+		 */
+		funcctx->max_calls = splitctx->wide_len;
+	}
+
+	funcctx = SRF_PERCALL_SETUP();
+	splitctx = (regexp_split_ctx *) funcctx->user_fctx;
+
+	if (funcctx->call_cntr > funcctx->max_calls)
+	{
+		/*
+		 * If we exceed wide_len something really wonky is going on,
+		 * since it is returning more matches than there are
+		 * characters in the string, which should not happen
+		 */
+		elog(ERROR, "set returning split function terminated after iterating %d times",
+			 funcctx->call_cntr);
+	}
+
+	if (splitctx->offset < splitctx->wide_len)
+		SRF_RETURN_NEXT(funcctx, get_next_split(splitctx));
+	else
+		SRF_RETURN_DONE(funcctx);
+}
+
+Datum regexp_split_to_table_no_flags(PG_FUNCTION_ARGS)
+{
+	return regexp_split_to_table(fcinfo);
+}
+
+Datum regexp_split_to_array(PG_FUNCTION_ARGS)
+{
+	ArrayBuildState 	*astate = NULL;
+	regexp_split_ctx 	*splitctx;
+	Oid 				 param_type;
+	int 				 nitems;
+
+	splitctx = setup_regexp_split(PG_GETARG_TEXT_P(0),
+								  PG_GETARG_TEXT_P(1),
+								  PG_GETARG_TEXT_P_IF_EXISTS(2));
+
+	/* get text type oid, too lazy to do it some other way */
+	param_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
+
+	for (nitems = 0; splitctx->offset < splitctx->wide_len; nitems++)
+	{
+		if (nitems > splitctx->wide_len)
+			elog(ERROR, "split function terminated after iterating %d times",
+				 nitems);
+
+		astate = accumArrayResult(astate,
+								  get_next_split(splitctx),
+								  false,
+								  param_type,
+								  CurrentMemoryContext);
+	}
+
+	PG_RETURN_ARRAYTYPE_P(makeArrayResult(astate, CurrentMemoryContext));
+}
+
+Datum regexp_split_to_array_no_flags(PG_FUNCTION_ARGS)
+{
+	return regexp_split_to_array(fcinfo);
+}
+
+static regexp_split_ctx *
+setup_regexp_split(text *str, text *pattern, text *flags)
+{
+	regexp_split_ctx *splitctx = palloc(sizeof(regexp_split_ctx));
+
+	splitctx->orig_str = str;
+	splitctx->orig_len = VARSIZE(splitctx->orig_str) - VARHDRSZ;
+
+	parse_re_comp_flags(&splitctx->flags, flags);
+	if (splitctx->flags.glob)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("regexp_split does not support the global option")));
+
+	splitctx->cpattern = RE_compile_and_cache(pattern, splitctx->flags.cflags);
+
+	splitctx->wide_str = palloc(sizeof(pg_wchar) * (splitctx->orig_len + 1));
+	splitctx->wide_len = pg_mb2wchar_with_len(VARDATA(splitctx->orig_str),
+											  splitctx->wide_str,
+											  splitctx->orig_len);
+
+	splitctx->offset = 0;
+
+	splitctx->match.rm_so = -1;
+	/* both < 0 but not equal */
+	splitctx->match.rm_eo = -2;
+
+	return splitctx;
+}
+
+static Datum
+get_next_split(regexp_split_ctx *splitctx)
+{
+	regmatch_t *pmatch = &(splitctx->match);
+
+	for (;;)
+	{
+		Datum result;
+		int	  startpos = splitctx->offset + 1;
+
+		/*
+		 * If the last match was zero-length, we need to push the
+		 * offset forward to avoid matching the same place forever
+		 */
+		if (pmatch->rm_so == pmatch->rm_eo)
+			splitctx->offset++;
+
+		if (RE_wchar_execute(splitctx->cpattern,
+							 splitctx->wide_str,
+							 splitctx->wide_len,
+							 splitctx->offset,
+							 1,
+							 pmatch))
+		{
+			int length = splitctx->match.rm_so - startpos + 1;
+
+			/*
+			 * If we are trying to match at the beginning of the string and
+			 * we got a zero-length match, or if we just matched where we
+			 * left off last time, go around the loop again and increment
+			 * the offset.  If we have incremented the offset already and
+			 * it matched at the new offset, that's ok
+			 */
+			if (length == 0)
+				continue;
+
+			result = DirectFunctionCall3(text_substr,
+										 PointerGetDatum(splitctx->orig_str),
+										 Int32GetDatum(startpos),
+										 Int32GetDatum(length));
+
+			/* set the offset to the end of this match for next time */
+			splitctx->offset = pmatch->rm_eo;
+
+			return result;
+		}
+
+		/* no more matches, return rest of string */
+		result = DirectFunctionCall2(text_substr_no_len,
+									 PointerGetDatum(splitctx->orig_str),
+									 Int32GetDatum(startpos));
+
+		/* so we know we're done next time through */
+		splitctx->offset = splitctx->wide_len;
+
+		return result;
+	}
+}
+
 /*
  * report whether regex_flavor is currently BASIC
  */
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 2327e1cab5e..2bd1eda199d 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.392 2007/03/20 03:53:26 wieck Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.393 2007/03/20 05:45:00 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200703190
+#define CATALOG_VERSION_NO	200703201
 
 #endif
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 6148702f5ee..8007129a1bb 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.448 2007/03/16 17:57:36 mha Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.449 2007/03/20 05:45:00 neilc Exp $
  *
  * NOTES
  *	  The script catalog/genbki.sh reads this file and generates .bki
@@ -2261,8 +2261,20 @@ DATA(insert OID =  2284 ( regexp_replace	   PGNSP PGUID 12 1 0 f f t f i 3 25 "2
 DESCR("replace text using regexp");
 DATA(insert OID =  2285 ( regexp_replace	   PGNSP PGUID 12 1 0 f f t f i 4 25 "25 25 25 25" _null_ _null_ _null_ textregexreplace - _null_ ));
 DESCR("replace text using regexp");
+DATA(insert OID =  2763 ( regexp_matches   PGNSP PGUID 12 1 1 f f t t i 2 1009 "25 25" _null_ _null_ _null_	regexp_matches_no_flags - _null_ ));
+DESCR("return all match groups for regexp");
+DATA(insert OID =  2764 ( regexp_matches   PGNSP PGUID 12 1 10 f f t t i 3 1009 "25 25 25" _null_ _null_ _null_	regexp_matches - _null_ ));
+DESCR("return all match groups for regexp");
 DATA(insert OID =  2088 ( split_part   PGNSP PGUID 12 1 0 f f t f i 3 25 "25 25 23" _null_ _null_ _null_	split_text - _null_ ));
 DESCR("split string by field_sep and return field_num");
+DATA(insert OID =  2765 ( regexp_split_to_table PGNSP PGUID 12 1 1000 f f t t i 2 25 "25 25" _null_ _null_ _null_	regexp_split_to_table_no_flags - _null_ ));
+DESCR("split string by pattern");
+DATA(insert OID =  2766 ( regexp_split_to_table PGNSP PGUID 12 1 1000 f f t t i 3 25 "25 25 25" _null_ _null_ _null_	regexp_split_to_table - _null_ ));
+DESCR("split string by pattern");
+DATA(insert OID =  2767 ( regexp_split_to_array PGNSP PGUID 12 1 0 f f t f i 2 1009 "25 25" _null_ _null_ _null_	regexp_split_to_array_no_flags - _null_ ));
+DESCR("split string by pattern");
+DATA(insert OID =  2768 ( regexp_split_to_array PGNSP PGUID 12 1 0 f f t f i 3 1009 "25 25 25" _null_ _null_ _null_	regexp_split_to_array - _null_ ));
+DESCR("split string by pattern");
 DATA(insert OID =  2089 ( to_hex	   PGNSP PGUID 12 1 0 f f t f i 1 25 "23" _null_ _null_ _null_	to_hex32 - _null_ ));
 DESCR("convert int4 number to hex");
 DATA(insert OID =  2090 ( to_hex	   PGNSP PGUID 12 1 0 f f t f i 1 25 "20" _null_ _null_ _null_	to_hex64 - _null_ ));
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 70c2142d8d4..b2a55bbbb98 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.289 2007/02/23 21:59:45 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.290 2007/03/20 05:45:00 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -478,6 +478,12 @@ extern Datum textregexsubstr(PG_FUNCTION_ARGS);
 extern Datum textregexreplace_noopt(PG_FUNCTION_ARGS);
 extern Datum textregexreplace(PG_FUNCTION_ARGS);
 extern Datum similar_escape(PG_FUNCTION_ARGS);
+extern Datum regexp_matches(PG_FUNCTION_ARGS);
+extern Datum regexp_matches_no_flags(PG_FUNCTION_ARGS);
+extern Datum regexp_split_to_table(PG_FUNCTION_ARGS);
+extern Datum regexp_split_to_table_no_flags(PG_FUNCTION_ARGS);
+extern Datum regexp_split_to_array(PG_FUNCTION_ARGS);
+extern Datum regexp_split_to_array_no_flags(PG_FUNCTION_ARGS);
 extern bool regex_flavor_is_basic(void);
 
 /* regproc.c */
diff --git a/src/test/regress/expected/strings.out b/src/test/regress/expected/strings.out
index 20081f699b6..e11dfc35d78 100644
--- a/src/test/regress/expected/strings.out
+++ b/src/test/regress/expected/strings.out
@@ -217,9 +217,232 @@ SELECT regexp_replace('AAA aaa', 'A+', 'Z', 'gi');
  Z Z
 (1 row)
 
--- invalid option of REGEXP_REPLACE
+-- invalid regexp option
 SELECT regexp_replace('AAA aaa', 'A+', 'Z', 'z');
-ERROR:  invalid option of regexp_replace: z
+ERROR:  invalid regexp option: z
+-- set so we can tell NULL from empty string
+\pset null '\\N'
+-- return all matches from regexp
+SELECT regexp_matches('foobarbequebaz', $re$(bar)(beque)$re$);
+ regexp_matches 
+----------------
+ {bar,beque}
+(1 row)
+
+-- test case insensitive
+SELECT regexp_matches('foObARbEqUEbAz', $re$(bar)(beque)$re$, 'i');
+ regexp_matches 
+----------------
+ {bAR,bEqUE}
+(1 row)
+
+-- global option - more than one match
+SELECT regexp_matches('foobarbequebazilbarfbonk', $re$(b[^b]+)(b[^b]+)$re$, 'g');
+ regexp_matches 
+----------------
+ {bar,beque}
+ {bazil,barf}
+(2 rows)
+
+-- empty capture group (matched empty string)
+SELECT regexp_matches('foobarbequebaz', $re$(bar)(.*)(beque)$re$);
+ regexp_matches 
+----------------
+ {bar,"",beque}
+(1 row)
+
+-- no match
+SELECT regexp_matches('foobarbequebaz', $re$(bar)(.+)(beque)$re$);
+ regexp_matches 
+----------------
+(0 rows)
+
+-- optional capture group did not match, null entry in array
+SELECT regexp_matches('foobarbequebaz', $re$(bar)(.+)?(beque)$re$);
+  regexp_matches  
+------------------
+ {bar,NULL,beque}
+(1 row)
+
+-- no capture groups
+SELECT regexp_matches('foobarbequebaz', $re$barbeque$re$);
+ regexp_matches 
+----------------
+ {barbeque}
+(1 row)
+
+-- give me errors
+SELECT regexp_matches('foobarbequebaz', $re$(bar)(beque)$re$, 'zipper');
+ERROR:  invalid regexp option: z
+SELECT regexp_matches('foobarbequebaz', $re$(barbeque$re$);
+ERROR:  invalid regular expression: parentheses () not balanced
+SELECT regexp_matches('foobarbequebaz', $re$(bar)(beque){2,1}$re$);
+ERROR:  invalid regular expression: invalid repetition count(s)
+-- split string on regexp
+SELECT foo, length(foo) FROM regexp_split_to_table('the quick brown fox jumped over the lazy dog', $re$\s+$re$) AS foo;
+  foo   | length 
+--------+--------
+ the    |      3
+ quick  |      5
+ brown  |      5
+ fox    |      3
+ jumped |      6
+ over   |      4
+ the    |      3
+ lazy   |      4
+ dog    |      3
+(9 rows)
+
+SELECT regexp_split_to_array('the quick brown fox jumped over the lazy dog', $re$\s+$re$);
+             regexp_split_to_array              
+------------------------------------------------
+ {the,quick,brown,fox,jumped,over,the,lazy,dog}
+(1 row)
+
+SELECT foo, length(foo) FROM regexp_split_to_table('the quick brown fox jumped over the lazy dog', $re$\s*$re$) AS foo;
+ foo | length 
+-----+--------
+ t   |      1
+ h   |      1
+ e   |      1
+ q   |      1
+ u   |      1
+ i   |      1
+ c   |      1
+ k   |      1
+ b   |      1
+ r   |      1
+ o   |      1
+ w   |      1
+ n   |      1
+ f   |      1
+ o   |      1
+ x   |      1
+ j   |      1
+ u   |      1
+ m   |      1
+ p   |      1
+ e   |      1
+ d   |      1
+ o   |      1
+ v   |      1
+ e   |      1
+ r   |      1
+ t   |      1
+ h   |      1
+ e   |      1
+ l   |      1
+ a   |      1
+ z   |      1
+ y   |      1
+ d   |      1
+ o   |      1
+ g   |      1
+(36 rows)
+
+SELECT regexp_split_to_array('the quick brown fox jumped over the lazy dog', $re$\s*$re$);
+                           regexp_split_to_array                           
+---------------------------------------------------------------------------
+ {t,h,e,q,u,i,c,k,b,r,o,w,n,f,o,x,j,u,m,p,e,d,o,v,e,r,t,h,e,l,a,z,y,d,o,g}
+(1 row)
+
+SELECT foo, length(foo) FROM regexp_split_to_table('the quick brown fox jumped over the lazy dog', '') AS foo;
+ foo | length 
+-----+--------
+ t   |      1
+ h   |      1
+ e   |      1
+     |      1
+ q   |      1
+ u   |      1
+ i   |      1
+ c   |      1
+ k   |      1
+     |      1
+ b   |      1
+ r   |      1
+ o   |      1
+ w   |      1
+ n   |      1
+     |      1
+ f   |      1
+ o   |      1
+ x   |      1
+     |      1
+ j   |      1
+ u   |      1
+ m   |      1
+ p   |      1
+ e   |      1
+ d   |      1
+     |      1
+ o   |      1
+ v   |      1
+ e   |      1
+ r   |      1
+     |      1
+ t   |      1
+ h   |      1
+ e   |      1
+     |      1
+ l   |      1
+ a   |      1
+ z   |      1
+ y   |      1
+     |      1
+ d   |      1
+ o   |      1
+ g   |      1
+(44 rows)
+
+SELECT regexp_split_to_array('the quick brown fox jumped over the lazy dog', '');
+                                           regexp_split_to_array                                           
+-----------------------------------------------------------------------------------------------------------
+ {t,h,e," ",q,u,i,c,k," ",b,r,o,w,n," ",f,o,x," ",j,u,m,p,e,d," ",o,v,e,r," ",t,h,e," ",l,a,z,y," ",d,o,g}
+(1 row)
+
+-- case insensitive
+SELECT foo, length(foo) FROM regexp_split_to_table('thE QUick bROWn FOx jUMPed ovEr THE lazy dOG', 'e', 'i') AS foo;
+          foo          | length 
+-----------------------+--------
+ th                    |      2
+  QUick bROWn FOx jUMP |     21
+ d ov                  |      4
+ r TH                  |      4
+  lazy dOG             |      9
+(5 rows)
+
+SELECT regexp_split_to_array('thE QUick bROWn FOx jUMPed ovEr THE lazy dOG', 'e', 'i');
+                 regexp_split_to_array                  
+--------------------------------------------------------
+ {th," QUick bROWn FOx jUMP","d ov","r TH"," lazy dOG"}
+(1 row)
+
+-- no match of pattern
+SELECT foo, length(foo) FROM regexp_split_to_table('the quick brown fox jumped over the lazy dog', 'nomatch') AS foo;
+                     foo                      | length 
+----------------------------------------------+--------
+ the quick brown fox jumped over the lazy dog |     44
+(1 row)
+
+SELECT regexp_split_to_array('the quick brown fox jumped over the lazy dog', 'nomatch');
+              regexp_split_to_array               
+--------------------------------------------------
+ {"the quick brown fox jumped over the lazy dog"}
+(1 row)
+
+-- errors
+SELECT foo, length(foo) FROM regexp_split_to_table('thE QUick bROWn FOx jUMPed ovEr THE lazy dOG', 'e', 'zippy') AS foo;
+ERROR:  invalid regexp option: z
+SELECT regexp_split_to_array('thE QUick bROWn FOx jUMPed ovEr THE lazy dOG', 'e', 'zippy');
+ERROR:  invalid regexp option: z
+-- global option meaningless for regexp_split
+SELECT foo, length(foo) FROM regexp_split_to_table('thE QUick bROWn FOx jUMPed ovEr THE lazy dOG', 'e', 'g') AS foo;
+ERROR:  regexp_split does not support the global option
+SELECT regexp_split_to_array('thE QUick bROWn FOx jUMPed ovEr THE lazy dOG', 'e', 'g');
+ERROR:  regexp_split does not support the global option
+-- change NULL-display back
+\pset null ''
 -- E021-11 position expression
 SELECT POSITION('4' IN '1234567890') = '4' AS "4";
  4 
diff --git a/src/test/regress/sql/strings.sql b/src/test/regress/sql/strings.sql
index 570d9a27f46..389ff63517f 100644
--- a/src/test/regress/sql/strings.sql
+++ b/src/test/regress/sql/strings.sql
@@ -85,9 +85,60 @@ SELECT regexp_replace('1112223333', E'(\\d{3})(\\d{3})(\\d{4})', E'(\\1) \\2-\\3
 SELECT regexp_replace('AAA   BBB   CCC   ', E'\\s+', ' ', 'g');
 SELECT regexp_replace('AAA', '^|$', 'Z', 'g');
 SELECT regexp_replace('AAA aaa', 'A+', 'Z', 'gi');
--- invalid option of REGEXP_REPLACE
+-- invalid regexp option
 SELECT regexp_replace('AAA aaa', 'A+', 'Z', 'z');
 
+-- set so we can tell NULL from empty string
+\pset null '\\N'
+
+-- return all matches from regexp
+SELECT regexp_matches('foobarbequebaz', $re$(bar)(beque)$re$);
+
+-- test case insensitive
+SELECT regexp_matches('foObARbEqUEbAz', $re$(bar)(beque)$re$, 'i');
+
+-- global option - more than one match
+SELECT regexp_matches('foobarbequebazilbarfbonk', $re$(b[^b]+)(b[^b]+)$re$, 'g');
+
+-- empty capture group (matched empty string)
+SELECT regexp_matches('foobarbequebaz', $re$(bar)(.*)(beque)$re$);
+-- no match
+SELECT regexp_matches('foobarbequebaz', $re$(bar)(.+)(beque)$re$);
+-- optional capture group did not match, null entry in array
+SELECT regexp_matches('foobarbequebaz', $re$(bar)(.+)?(beque)$re$);
+
+-- no capture groups
+SELECT regexp_matches('foobarbequebaz', $re$barbeque$re$);
+
+-- give me errors
+SELECT regexp_matches('foobarbequebaz', $re$(bar)(beque)$re$, 'zipper');
+SELECT regexp_matches('foobarbequebaz', $re$(barbeque$re$);
+SELECT regexp_matches('foobarbequebaz', $re$(bar)(beque){2,1}$re$);
+
+-- split string on regexp
+SELECT foo, length(foo) FROM regexp_split_to_table('the quick brown fox jumped over the lazy dog', $re$\s+$re$) AS foo;
+SELECT regexp_split_to_array('the quick brown fox jumped over the lazy dog', $re$\s+$re$);
+
+SELECT foo, length(foo) FROM regexp_split_to_table('the quick brown fox jumped over the lazy dog', $re$\s*$re$) AS foo;
+SELECT regexp_split_to_array('the quick brown fox jumped over the lazy dog', $re$\s*$re$);
+SELECT foo, length(foo) FROM regexp_split_to_table('the quick brown fox jumped over the lazy dog', '') AS foo;
+SELECT regexp_split_to_array('the quick brown fox jumped over the lazy dog', '');
+-- case insensitive
+SELECT foo, length(foo) FROM regexp_split_to_table('thE QUick bROWn FOx jUMPed ovEr THE lazy dOG', 'e', 'i') AS foo;
+SELECT regexp_split_to_array('thE QUick bROWn FOx jUMPed ovEr THE lazy dOG', 'e', 'i');
+-- no match of pattern
+SELECT foo, length(foo) FROM regexp_split_to_table('the quick brown fox jumped over the lazy dog', 'nomatch') AS foo;
+SELECT regexp_split_to_array('the quick brown fox jumped over the lazy dog', 'nomatch');
+-- errors
+SELECT foo, length(foo) FROM regexp_split_to_table('thE QUick bROWn FOx jUMPed ovEr THE lazy dOG', 'e', 'zippy') AS foo;
+SELECT regexp_split_to_array('thE QUick bROWn FOx jUMPed ovEr THE lazy dOG', 'e', 'zippy');
+-- global option meaningless for regexp_split
+SELECT foo, length(foo) FROM regexp_split_to_table('thE QUick bROWn FOx jUMPed ovEr THE lazy dOG', 'e', 'g') AS foo;
+SELECT regexp_split_to_array('thE QUick bROWn FOx jUMPed ovEr THE lazy dOG', 'e', 'g');
+
+-- change NULL-display back
+\pset null ''
+
 -- E021-11 position expression
 SELECT POSITION('4' IN '1234567890') = '4' AS "4";