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authorLukas Larsson <[email protected]>2016-02-23 17:08:42 +0100
committerLukas Larsson <[email protected]>2016-04-15 15:07:10 +0200
commitecd20cf55ffcc45632825863ea8f0c7442553a0d (patch)
tree061ffb81ca9db4201e8e8b60f19880d5c19c6b56 /erts/doc/src/match_spec.xml
parentd89da98527e1a0855fef06cd27839416dfb6efd1 (diff)
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erts: Add tracing examples in match spec docs
Diffstat (limited to 'erts/doc/src/match_spec.xml')
-rw-r--r--erts/doc/src/match_spec.xml41
1 files changed, 40 insertions, 1 deletions
diff --git a/erts/doc/src/match_spec.xml b/erts/doc/src/match_spec.xml
index b49e1483aa..3944f24f84 100644
--- a/erts/doc/src/match_spec.xml
+++ b/erts/doc/src/match_spec.xml
@@ -528,7 +528,7 @@
</section>
<section>
- <title>Examples</title>
+ <title>ETS Examples</title>
<p>Match an argument list of three where the first and third arguments
are equal:</p>
<code type="none"><![CDATA[
@@ -619,5 +619,44 @@
<p>The function <c><![CDATA[ets:test_ms/2]]></c> can be useful for testing
complicated ets matches.</p>
</section>
+ <section>
+ <title>Tracing Examples</title>
+ <p>Only generate trace message if trace control word is set to 1:</p>
+ <code type="none"><![CDATA[
+[{'_',
+ [{'==',{get_tcw},{const, 1}}],
+ []}]
+ ]]></code>
+ <p>Only generate trace message if there is a seq trace token:</p>
+ <code type="none"><![CDATA[
+[{'_',
+ [{'==',{is_seq_trace},{const, 1}}],
+ []}]
+ ]]></code>
+ <p>Remove 'silent' trace flag when first argument is 'verbose'
+ and add it when it is 'silent':</p>
+ <code type="none"><![CDATA[
+[{'$1',
+ [{'==',{hd, '$1'},verbose}],
+ [{trace, [silent],[]}]},
+ {'$1',
+ [{'==',{hd, '$1'},silent}],
+ [{trace, [],[silent]}]}]
+ ]]></code>
+ <p>Add return_trace message if function is of arity 3:</p>
+ <code type="none"><![CDATA[
+[{'$1',
+ [{'==',{length, '$1'},3}],
+ [{return_trace}]},
+ {'_',[],[]}]
+ ]]></code>
+ <p>Only generate trace message if function is of arity 3 and first argument is 'trace':</p>
+ <code type="none"><![CDATA[
+[{['trace','$2','$3'],
+ [],
+ []},
+ {'_',[],[]}]
+ ]]></code>
+ </section>
</chapter>