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this in the global scope
Browser - window
Web worker - self
NodeJS - module.exports
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this inside a function?
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this inside a function?
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How to make this predictable?
Reasoning the value of this is tricky
Function.prototype.bind
Arrow function () => {}
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With .bind()
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With Arrow
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Calling a knowing function
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Extracting a method from an object
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Two syntaxes
Unary : :context.method()
Binary context: :method()
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Binary syntax
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Unary syntax
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Bind operator is good for virtual
methods
But relies on this to be bound
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Composing without this
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Pipeline operator |>
It is a syntax sugar for
function composition
It creates a way to streamline
a chain of functions
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Pipeline operator |>
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Function with more params
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Function with more params
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Awaiting a function
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Awaiting a function
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Awaiting a function
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Awaiting a function
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Awaiting a function
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Smart pipeline
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Smart pipeline
Two types bare style and topic style
() or [] are disallowed in bare style
When () or [] is needed, topic style
is used
# token is subject to change
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What about curry?
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F# pipeline proposal
Extends the minimal proposal with
an await step
Await step waits for the resolution of
the previous step
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F# pipeline proposal
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Partial application
f(…) arity = n;
partialapp(f(…)) arity = m;
m < n
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Partial application in ES
Achievable by
Function.prototype.bind
.bind() binds context and
parameters
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What about currying?
We can achieve partial application
with curry
Curry ≠ Partial application
Curry returns arity n-1
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Partial application with arrow
function
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Partial application proposal
Creates two new parameters tokens
? For single argument
. . . for multiple parameters
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Partial application syntax
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With arbitrary parameter
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The . . . token
Spread the unbound parameters
Useful when you want to bound first
or last parameter
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The . . . token
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The . . . token
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Partial application + pipeline
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Partial application + pipeline
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Should I use all of it in production?
These proposal are in very early
stage
The adoption of one, may change
the syntax/semantics of other
Not production ready (yet)