diff options
Diffstat (limited to 'system/doc/programming_examples/bit_syntax.xml')
| -rw-r--r-- | system/doc/programming_examples/bit_syntax.xml | 21 |
1 files changed, 9 insertions, 12 deletions
diff --git a/system/doc/programming_examples/bit_syntax.xml b/system/doc/programming_examples/bit_syntax.xml index 0af295b7b7..98ad2808cf 100644 --- a/system/doc/programming_examples/bit_syntax.xml +++ b/system/doc/programming_examples/bit_syntax.xml @@ -32,6 +32,8 @@ <section> <title>Introduction</title> + <p>The complete specification for the bit syntax appears in the + <seealso marker="doc/reference_manual:expressions#bit_syntax">Reference Manual</seealso>.</p> <p>In Erlang, a Bin is used for constructing binaries and matching binary patterns. A Bin is written with the following syntax:</p> <code type="none"><![CDATA[ @@ -45,7 +47,7 @@ Bin = <<E1, E2, ... En>>]]></code> <<E1, E2, ... En>> = Bin ]]></code> <p>Here, <c>Bin</c> is bound and the elements are bound or unbound, as in any match.</p> - <p>Since Erlang R12B, a Bin does not need to consist of a whole number of bytes.</p> + <p>A Bin does not need to consist of a whole number of bytes.</p> <p>A <em>bitstring</em> is a sequence of zero or more bits, where the number of bits does not need to be divisible by 8. If the number @@ -165,8 +167,9 @@ end.]]></code> separated by hyphens.</p> <taglist> <tag>Type</tag> - <item>The type can be <c>integer</c>, <c>float</c>, or - <c>binary</c>.</item> + <item>The most commonly used types are <c>integer</c>, <c>float</c>, and <c>binary</c>. + See <seealso marker="doc/reference_manual:expressions#bit_syntax">Bit Syntax Expressions in the Reference Manual</seealso> for a complete description. +</item> <tag>Signedness</tag> <item>The signedness specification can be either <c>signed</c> or <c>unsigned</c>. Notice that signedness only matters for @@ -181,7 +184,7 @@ end.]]></code> <item>The unit size is given as <c>unit:IntegerLiteral</c>. The allowed range is 1-256. It is multiplied by the <c>Size</c> specifier to give the effective size of - the segment. Since Erlang R12B, the unit size specifies the alignment + the segment. The unit size specifies the alignment for binary segments without size.</item> </taglist> <p><em>Example:</em></p> @@ -319,21 +322,15 @@ foo(<<A:8,Rest/bitstring>>) ->]]></code> <section> <title>Appending to a Binary</title> - <p>Since Erlang R12B, the following function for creating a binary out of - a list of triples of integers is efficient:</p> + <p>Appending to a binary in an efficient way can be done as follows:</p> <code type="none"><![CDATA[ triples_to_bin(T) -> triples_to_bin(T, <<>>). triples_to_bin([{X,Y,Z} | T], Acc) -> - triples_to_bin(T, <<Acc/binary,X:32,Y:32,Z:32>>); % inefficient before R12B + triples_to_bin(T, <<Acc/binary,X:32,Y:32,Z:32>>); triples_to_bin([], Acc) -> Acc.]]></code> - <p>In previous releases, this function was highly inefficient, because - the binary constructed so far (<c>Acc</c>) was copied in each recursion step. - That is no longer the case. For more information, see - <seealso marker="doc/efficiency_guide:introduction"> - Efficiency Guide</seealso>.</p> </section> </chapter> |