Doc: improve documentation for ^@ starts-with operator.

This operator wasn't formally documented anywhere.  To give it
a natural home, relabel the functions-string-other table as
"Other String Functions and Operators", which is more parallel
to the functions-string-sql table anyway.

While here, add cross-references to the pattern match and text
search sections.  It seems moderately likely that people would
come to this section looking for those (but I don't want to
actually list them in these tables).

Discussion: https://postgr.es/m/CADT4RqB13KQHOJqqQ+WXmYtJrukS2UiFdtfTvT-XA3qYLyB6Cw@mail.gmail.com

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 42dff83e160cb9e372dfdcf5b6a9f5e72c7a315a..5677032cb28f50e7362e5f5b76fd3321c0dad8d6 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -2708,18 +2708,23 @@ repeat('Pg', 4) PgPgPgPg
    
 
    
-    Additional string manipulation functions are available and are
-    listed in .  Some of them are used internally to implement the
-    SQL-standard string functions listed in .
+    Additional string manipulation functions and operators are available
+    and are listed in .  (Some of
+    these are used internally to implement
+    the SQL-standard string functions listed in
+    .)
+    There are also pattern-matching operators, which are described in
+    , and operators for full-text
+    search, which are described in .
    
 
    
-    Other String Functions
+    Other String Functions<span class="marked"> and Operators</span>
     
      
       
        
-        Function
+        Function/Operator
        
        
         Description
@@ -2731,6 +2736,25 @@ repeat('Pg', 4) PgPgPgPg
      
 
      
+      
+       
+        
+         character string
+         prefix test
+        
+        text ^@ text
+        boolean
+       
+       
+        Returns true if the first string starts with the second string
+        (equivalent to the starts_with() function).
+       
+       
+        'alphabet' ^@ 'alph'
+        t
+       
+      
+
       
        
         
@@ -5285,9 +5309,10 @@ cast(-44 as bit(12))           111111010100
    
 
    
-    Also see the prefix operator ^@ and corresponding
-    starts_with function, which are useful in cases
-    where simply matching the beginning of a string is needed.
+    Also see the starts-with operator ^@ and the
+    corresponding starts_with() function, which are
+    useful in cases where simply matching the beginning of a string is
+    needed.