diff options
Diffstat (limited to 'system/doc/efficiency_guide/myths.xml')
| -rw-r--r-- | system/doc/efficiency_guide/myths.xml | 31 |
1 files changed, 3 insertions, 28 deletions
diff --git a/system/doc/efficiency_guide/myths.xml b/system/doc/efficiency_guide/myths.xml index 5d3ad78b23..7e2f3c8465 100644 --- a/system/doc/efficiency_guide/myths.xml +++ b/system/doc/efficiency_guide/myths.xml @@ -24,7 +24,7 @@ The Initial Developer of the Original Code is Ericsson AB. </legalnotice> - <title>The Eight Myths of Erlang Performance</title> + <title>The Six Myths of Erlang Performance</title> <prepared>Bjorn Gustavsson</prepared> <docno></docno> <date>2007-11-10</date> @@ -35,38 +35,13 @@ <marker id="myths"></marker> <p>Some truths seem to live on well beyond their best-before date, perhaps because "information" spreads faster from person-to-person - than a single release note that says, for example, that funs - have become faster.</p> + than a single release note that says, for example, that body-recursive + calls have become faster.</p> <p>This section tries to kill the old truths (or semi-truths) that have become myths.</p> <section> - <title>Myth: Funs are Slow</title> - <p>Funs used to be very slow, slower than <c>apply/3</c>. - Originally, funs were implemented using nothing more than - compiler trickery, ordinary tuples, <c>apply/3</c>, and a great - deal of ingenuity.</p> - - <p>But that is history. Funs was given its own data type - in R6B and was further optimized in R7B. - Now the cost for a fun call falls roughly between the cost for a call - to a local function and <c>apply/3</c>.</p> - </section> - - <section> - <title>Myth: List Comprehensions are Slow</title> - - <p>List comprehensions used to be implemented using funs, and in the - old days funs were indeed slow.</p> - - <p>Nowadays, the compiler rewrites list comprehensions into an ordinary - recursive function. Using a tail-recursive function with - a reverse at the end would be still faster. Or would it? - That leads us to the next myth.</p> - </section> - - <section> <title>Myth: Tail-Recursive Functions are Much Faster Than Recursive Functions</title> |