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| author | Björn-Egil Dahlberg <[email protected]> | 2016-12-12 16:54:42 +0100 |
|---|---|---|
| committer | Björn-Egil Dahlberg <[email protected]> | 2016-12-12 17:11:54 +0100 |
| commit | 4fbe5a6ea946de03693ffa1be671cf9af93e55eb (patch) | |
| tree | e0f16954468d378d181a2463e099b291c61c65b2 /system/doc | |
| parent | 74f4aa2897e7b2a3bac688d808b9b396fc35d1aa (diff) | |
| download | otp-4fbe5a6ea946de03693ffa1be671cf9af93e55eb.tar.gz otp-4fbe5a6ea946de03693ffa1be671cf9af93e55eb.tar.bz2 otp-4fbe5a6ea946de03693ffa1be671cf9af93e55eb.zip | |
doc: Enchance map pair optional/mandatory notes
Diffstat (limited to 'system/doc')
| -rw-r--r-- | system/doc/reference_manual/typespec.xml | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/system/doc/reference_manual/typespec.xml b/system/doc/reference_manual/typespec.xml index c117b6e1d0..a0ea41cb3b 100644 --- a/system/doc/reference_manual/typespec.xml +++ b/system/doc/reference_manual/typespec.xml @@ -142,8 +142,8 @@ PairList :: Pair | Pair, PairList - Pair :: Type := Type %% denotes a pair that must be present - | Type => Type + Pair :: Type := Type %% denotes a mandatory pair + | Type => Type %% denotes an optional pair TList :: Type | Type, TList @@ -176,7 +176,11 @@ The general form of maps is <c>#{PairList}</c>. The key types in <c>PairList</c> are allowed to overlap, and if they do, the leftmost pair takes precedence. A map pair has a key in - <c>PairList</c> if it belongs to this type. + <c>PairList</c> if it belongs to this type. A <c>PairList</c> may contain + both 'mandatory' and 'optional' pairs where 'mandatory' denotes that + a key type, and its associated value type, must be present. + In the case of an 'optional' pair it is not required for the key type to + be present. </p> <p> Notice that the syntactic representation of <c>map()</c> is |