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| author | Tuncer Ayaz <[email protected]> | 2010-04-20 20:44:45 +0200 |
|---|---|---|
| committer | Tuncer Ayaz <[email protected]> | 2010-04-20 20:46:49 +0200 |
| commit | 45c380d1b77198449fb8e3beadb39dc8f77abb72 (patch) | |
| tree | 3e3ccacf78bf209a0797196084cab0e599233858 /system/doc | |
| parent | 3829e5facc98f1c1d3113b648c0b9fa7362cad32 (diff) | |
| download | otp-45c380d1b77198449fb8e3beadb39dc8f77abb72.tar.gz otp-45c380d1b77198449fb8e3beadb39dc8f77abb72.tar.bz2 otp-45c380d1b77198449fb8e3beadb39dc8f77abb72.zip | |
Document R14 paren-less record access/update
Add a section to the reference manual describing the R14
change to not require parentheses when accessing or updating
fields in nested records.
Signed-off-by: Tuncer Ayaz <[email protected]>
Diffstat (limited to 'system/doc')
| -rw-r--r-- | system/doc/reference_manual/records.xml | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/system/doc/reference_manual/records.xml b/system/doc/reference_manual/records.xml index e2fe5fe8de..e901b7bccf 100644 --- a/system/doc/reference_manual/records.xml +++ b/system/doc/reference_manual/records.xml @@ -145,6 +145,29 @@ is_person(_P) -> </section> <section> + <title>Nested records</title> + <p>Beginning with R14 parentheses when accessing or updating nested + records can be omitted. Assuming we have the following record + definitions:</p> + <pre> +-record(nrec0, {name = "nested0"}). +-record(nrec1, {name = "nested1", nrec0=#nrec0{}}). +-record(nrec2, {name = "nested2", nrec1=#nrec1{}}). + +N2 = #nrec2{}, + </pre> + <p>Before R14 you would have needed to use parentheses as following:</p> + <pre> +"nested0" = ((N2#nrec2.nrec1)#nrec1.nrec0)#nrec0.name, +N0n = ((N2#nrec2.nrec1)#nrec1.nrec0)#nrec0{name = "nested0a"}, + </pre> + <p>Since R14 you can also write:</p> + <pre> +"nested0" = N2#nrec2.nrec1#nrec1.nrec0#nrec0.name, +N0n = N2#nrec2.nrec1#nrec1.nrec0#nrec0{name = "nested0a"},</pre> + </section> + + <section> <title>Internal Representation of Records</title> <p>Record expressions are translated to tuple expressions during compilation. A record defined as</p> |