diff options
Diffstat (limited to 'system/doc/reference_manual/expressions.xml')
| -rw-r--r-- | system/doc/reference_manual/expressions.xml | 41 |
1 files changed, 26 insertions, 15 deletions
diff --git a/system/doc/reference_manual/expressions.xml b/system/doc/reference_manual/expressions.xml index 893398b71b..1a3d19aed1 100644 --- a/system/doc/reference_manual/expressions.xml +++ b/system/doc/reference_manual/expressions.xml @@ -4,7 +4,7 @@ <chapter> <header> <copyright> - <year>2003</year><year>2015</year> + <year>2003</year><year>2016</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -245,13 +245,13 @@ lists:keysearch(Name, 1, List)</code> handle(Msg, State) spawn(m, init, [])</code> <p><em>Examples</em> where <c>ExprF</c> is a fun:</p> - <code type="none"> -Fun1 = fun(X) -> X+1 end -Fun1(3) -=> 4 - -fun lists:append/2([1,2], [3,4]) -=> [1,2,3,4]</code> + <pre> +1> <input>Fun1 = fun(X) -> X+1 end,</input> +<input>Fun1(3).</input> +4 +2> <input>fun lists:append/2([1,2], [3,4]).</input> +[1,2,3,4] +3> </pre> <p>Notice that when calling a local function, there is a difference between using the implicitly or fully qualified function name. @@ -1004,7 +1004,7 @@ M4 = M3#{a := 2, b := 3}. % 'a' and 'b' was added in `M1` and `M2`.</code> </p> <list> <item><p>A <c>badmatch</c> exception.</p> - <p>This is if it is used in the context of the matching operator + <p>This is if it is used in the context of the match operator as in the example.</p> </item> <item><p>Or resulting in the next clause being tested in function heads and @@ -1085,7 +1085,7 @@ Ei = Value | <p>Used in a bit string construction, <c>Value</c> is an expression that is to evaluate to an integer, float, or bit string. If the expression is not a single literal or variable, it - is to be enclosed in parenthesis.</p> + is to be enclosed in parentheses.</p> <p>Used in a bit string matching, <c>Value</c> must be a variable, or an integer, float, or string.</p> @@ -1319,7 +1319,7 @@ catch Expr</code> {'EXIT',{badarith,[...]}}</pre> <p>Notice that <c>catch</c> has low precedence and catch subexpressions often needs to be enclosed in a block - expression or in parenthesis:</p> + expression or in parentheses:</p> <pre> 3> <input>A = catch 1+2.</input> ** 1: syntax error before: 'catch' ** @@ -1541,7 +1541,16 @@ end</pre> <pre> 1> <input>[X*2 || X <- [1,2,3]].</input> [2,4,6]</pre> - <p>More examples are provoded in + <p>When there are no generators or bit string generators, a list comprehension + returns either a list with one element (the result of evaluating <c>Expr</c>) + if all filters are true or an empty list otherwise.</p> + <p><em>Example:</em></p> + <pre> +1> <input>[2 || is_integer(2)].</input> +[2] +2> <input>[x || is_integer(x)].</input> +[]</pre> + <p>More examples are provided in <seealso marker="doc/programming_examples:list_comprehensions"> Programming Examples.</seealso></p> @@ -1556,9 +1565,11 @@ end</pre> <p>Bit string comprehensions are written with the following syntax:</p> <pre> -<< BitString || Qualifier1,...,QualifierN >></pre> - <p>Here, <c>BitString</c> is a bit string expression and each - <c>Qualifier</c> is either a generator, a bit string generator or a filter.</p> +<< BitStringExpr || Qualifier1,...,QualifierN >></pre> + <p><c>BitStringExpr</c> is an expression that evalutes to a bit + string. If <c>BitStringExpr</c> is a function call, it must be + enclosed in parentheses. Each <c>Qualifier</c> is either a + generator, a bit string generator or a filter.</p> <list type="bulleted"> <item>A <em>generator</em> is written as: <br></br> <c><![CDATA[Pattern <- ListExpr]]></c>. <br></br> |