diff options
Diffstat (limited to 'system')
| -rw-r--r-- | system/doc/reference_manual/expressions.xml | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/system/doc/reference_manual/expressions.xml b/system/doc/reference_manual/expressions.xml index 0dc6bfe576..e9de3e006e 100644 --- a/system/doc/reference_manual/expressions.xml +++ b/system/doc/reference_manual/expressions.xml @@ -954,19 +954,20 @@ Ei = Value | <title>Fun Expressions</title> <pre> fun - (Pattern11,...,Pattern1N) [when GuardSeq1] -> - Body1; + [Name](Pattern11,...,Pattern1N) [when GuardSeq1] -> + Body1; ...; - (PatternK1,...,PatternKN) [when GuardSeqK] -> - BodyK + [Name](PatternK1,...,PatternKN) [when GuardSeqK] -> + BodyK end</pre> <p>A fun expression begins with the keyword <c>fun</c> and ends with the keyword <c>end</c>. Between them should be a function declaration, similar to a - <seealso marker="functions#syntax">regular function declaration</seealso>, except that no function name is - specified.</p> - <p>Variables in a fun head shadow variables in the - function clause surrounding the fun expression, and + <seealso marker="functions#syntax">regular function declaration</seealso>, + except that the function name is optional and should be a variable if + any.</p> + <p>Variables in a fun head shadow the function name and both shadow + variables in the function clause surrounding the fun expression, and variables bound in a fun body are local to the fun body.</p> <p>The return value of the expression is the resulting fun.</p> <p>Examples:</p> @@ -978,7 +979,11 @@ end</pre> 3> <input>Fun2 = fun (X) when X>=5 -> gt; (X) -> lt end.</input> #Fun<erl_eval.6.39074546> 4> <input>Fun2(7).</input> -gt</pre> +gt +5> <input>Fun3 = fun Fact(1) -> 1; Fact(X) when X > 1 -> X * Fact(X - 1) end.</input> +#Fun<erl_eval.6.39074546> +6> <input>Fun3(4).</input> +24</pre> <p>The following fun expressions are also allowed:</p> <pre> fun Name/Arity |