PopFront

Name	Mandatory	Description	Default	Type
⬅️ Input		Any input is ignored.		None
Output ➡️		The element popped from the sequence.		Any
Name	No	The name of the variable.	``	StringVar(Any)
Key	No	The key of the value to read from the table (parameter applicable only if the target variable is a table).	none	Any
Global	No	If the variable is available to all of the wires in the same mesh.	false	Bool

Pops (removes and outputs) the first element of the sequence variable. Works only on sequences. If the variable is not a sequence or the sequence is empty, an error is thrown.

Details

PopFront drops (removes) the first element of the sequence variable that has been passed to in the :Name parameter and makes it available to the next shard as its input.

This shard works on both sequences and tables. Parameter :Key applies only to tables.

Since variables may be locally scoped (created with (:Global false); exists only for current wire) or globally scoped (created with (:Global true); exists for all wires of that mesh), both parameters :Global and :Name are used in combination to identify the correct variable to pop elements from.

Input field is ignored and the output of this shard is the element which was popped from the sequence passed to it via the :Name parameter.

See also

• Clear
• Drop
• DropFront
• Erase
• Pop
• PrependTo
• Remove

Examples

Code

; pop first element from a local sequence
[10 20 30 40] >= seq           ; create a local sequence
Get(seq) | Log                ; local sequence => [10, 20, 30, 40]
PopFront(Name: seq) | Log     ; pops the first element as output => 10
Get(seq) | Log                ; updated sequence => [20, 30, 40]

; pop first element from a same-name global sequence
[11 21 31 41] | Set(seq Global: true)  ; create global sequence
Get(seq Global: true) | Log   ; global sequence => [11, 21, 31, 41]
PopFront(Name: seq Global: true) | Log ; pops the first element as output => 11
Get(seq Global: true) | Log   ; updated sequence => [21, 31, 41]

[info] Set - Warning: setting an already exposed variable "seq", use Update to avoid this warning.
[info] [sample-wire] [10 20 30 40]
[info] [sample-wire] 10
[info] [sample-wire] [20 30 40]
[info] [sample-wire] [11 21 31 41]
[info] [sample-wire] 11
[info] [sample-wire] [21 31 41]

 

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