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Improve levenshtein() docs.

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Fix chars-vs-bytes confusion here too.  Improve poor grammar and
markup.
This commit is contained in:
Tom Lane 2016-01-22 12:29:07 -05:00
parent a396144ac0
commit 80aa219146
1 changed files with 11 additions and 6 deletions
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doc/src/sgml/fuzzystrmatch.sgml
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@ -106,15 +106,20 @@ levenshtein_less_equal(text source, text target, int max_d) returns int
<para>
Both <literal>source</literal> and <literal>target</literal> can be any
non-null string, with a maximum of 255 bytes. The cost parameters
non-null string, with a maximum of 255 characters. The cost parameters
specify how much to charge for a character insertion, deletion, or
substitution, respectively. You can omit the cost parameters, as in
the second version of the function; in that case they all default to 1.
<literal>levenshtein_less_equal</literal> is accelerated version of
levenshtein function for low values of distance. If actual distance
is less or equal then max_d, then <literal>levenshtein_less_equal</literal>
returns accurate value of it. Otherwise this function returns value
which is greater than max_d.
</para>
<para>
<function>levenshtein_less_equal</function> is an accelerated version of the
Levenshtein function for use when only small distances are of interest.
If the actual distance is less than or equal to <literal>max_d</>,
then <function>levenshtein_less_equal</function> returns the correct
distance; otherwise it returns some value greater than <literal>max_d</>.
If <literal>max_d</> is negative then the behavior is the same as
<function>levenshtein</function>.
</para>
<para>