Symbol and Operator Reference (F#)

!

Reference Cells (F#)

Computation Expressions (F#)

• Dereferences a reference cell.

• After a keyword, indicates a modified version of the keyword's behavior as controlled by a workflow.

!=

Not applicable.

• Not used in F#. Use <> for inequality operations.

"

Literals (F#)

• Delimits a text string.

#

Compiler Directives (F#)

Flexible Types (F#)

• Prefixes a preprocessor or compiler directive, such as #light.

• When used with a type, indicates a flexible type, which refers to a type or any one of its derived types.

$

No more information available.

• Used internally for certain compiler-generated variable and function names.

%

Arithmetic Operators (F#)

Code Quotations (F#)

• Computes the integer modulus.

• Used for splicing quotations.

&

Match Expressions (F#)

• Computes the address of a mutable value, for use when interoperating with other languages.

• Used in AND patterns.

&&

Boolean Operators (F#)

• Computes the Boolean AND operation.

&&&

Bitwise Operators (F#)

• Computes the bitwise AND operation.

'

Literals (F#)

Automatic Generalization (F#)

• Delimits a single-character literal.

• Indicates a generic type parameter.

``...``

No more information available.

• Delimits an identifier that would otherwise not be a legal identifier, such as a language keyword.

( )

Unit Type (F#)

• Represents the single value of the unit type.

(...)

Tuples (F#)

Operator Overloading (F#)

• Indicates the order in which expressions are evaluated.

• Delimits a tuple.

• Used in operator definitions.

(*...*)

• Delimits a comment that could span multiple lines.

(|...|)

Active Patterns (F#)

• Delimits an active pattern. Also called banana clips.

*

Arithmetic Operators (F#)

Tuples (F#)

Units of Measure (F#)

• When used as a binary operator, multiplies the left and right sides.

• In types, indicates pairing in a tuple.

• Used in units of measure types.

**

Arithmetic Operators (F#)

• Computes the exponentiation operation (x ** y means x to the power of y).

+

Arithmetic Operators (F#)

• When used as a binary operator, adds the left and right sides.

• When used as a unary operator, indicates a positive quantity. (Formally, it produces the same value with the sign unchanged.)

,

Tuples (F#)

• Separates the elements of a tuple, or type parameters.

-

Arithmetic Operators (F#)

• When used as a binary operator, subtracts the right side from the left side.

• When used as a unary operator, performs a negation operation.

->

Functions (F#)

Match Expressions (F#)

• In function types, delimits arguments and return values.

• Yields an expression (in sequence expressions); equivalent to the yield keyword.

• Used in match expressions

.

Members (F#)

Primitive Types (F#)

• Accesses a member, and separates individual names in a fully qualified name.

• Specifies a decimal point in floating point numbers.

..

Loops: for...in Expression (F#)

• Specifies a range.

.. ..

Loops: for...in Expression (F#)

• Specifies a range together with an increment.

.[...]

Arrays (F#)

• Accesses an array element.

/

Arithmetic Operators (F#)

Units of Measure (F#)

• Divides the left side (numerator) by the right side (denominator).

• Used in units of measure types.

//

• Indicates the beginning of a single-line comment.

///

XML Documentation (F#)

• Indicates an XML comment.

:

Functions (F#)

• In a type annotation, separates a parameter or member name from its type.

::

Lists (F#)

Match Expressions (F#)

• Creates a list. The element on the left side is appended to the list on the right side.

• Used in pattern matching to separate the parts of a list.

:=

Reference Cells (F#)

• Assigns a value to a reference cell.

:>

Casting and Conversions (F#)

• Converts a type to type that is higher in the hierarchy.

:?

Match Expressions (F#)

• Returns true if the value matches the specified type; otherwise, returns false (type test operator).

:?>

Casting and Conversions (F#)

• Converts a type to a type that is lower in the hierarchy.

;

Verbose Syntax (F#)

Lists (F#)

Records (F#)

• Separates expressions (used mostly in verbose syntax).

• Separates elements of a list.

• Separates fields of a record.

<

Arithmetic Operators (F#)

• Computes the less-than operation.

<<

Functions (F#)

• Composes two functions in reverse order; the second one is executed first (backward composition operator).

<<<

Bitwise Operators (F#)

• Shifts bits in the quantity on the left side to the left by the number of bits specified on the right side.

<-

Values (F#)

• Assigns a value to a variable.

<...>

Automatic Generalization (F#)

• Delimits type parameters.

<>

Arithmetic Operators (F#)

• Returns true if the left side is not equal to the right side; otherwise, returns false.

<=

Arithmetic Operators (F#)

• Returns true if the left side is less than or equal to the right side; otherwise, returns false.

<|

Functions (F#)

• Passes the result of the expression on the right side to the function on left side (backward pipe operator).

<@...@>

Code Quotations (F#)

• Delimits a typed code quotation.

<@@...@@>

Code Quotations (F#)

• Delimits an untyped code quotation.

=

Arithmetic Operators (F#)

• Returns true if the left side is equal to the right side; otherwise, returns false.

==

Not applicable.

• Not used in F#. Use = for equality operations.

>

Arithmetic Operators (F#)

• Returns true if the left side is greater than the right side; otherwise, returns false.

>>

Functions (F#)

• Composes two functions (forward composition operator).

>>>

Bitwise Operators (F#)

• Shifts bits in the quantity on the left side to the right by the number of places specified on the right side.

>=

Arithmetic Operators (F#)

• Returns true if the right side is greater than or equal to the left side; otherwise, returns false.

?

Parameters and Arguments (F#)

• Specifies an optional argument.

• Used as an operator for dynamic method and property calls. You must provide your own implementation.

? ... <- ...

No more information available.

• Used as an operator for setting dynamic properties. You must provide your own implementation.

@

Lists (F#)

Strings (F#)

• Concatenates two lists.

• When placed before a string literal, indicates that the string is to be interpreted verbatim, with no interpretation of escape characters.

[...]

Lists (F#)

• Delimits the elements of a list.

[|...|]

Arrays (F#)

• Delimits the elements of an array.

[<...>]

Attributes (F#)

• Delimits an attribute.

\

Strings (F#)

• Escapes the next character; used in character and string literals.

^

Statically Resolved Type Parameters (F#)

Strings (F#)

• Specifies type parameters that must be resolved at compile time, not at runtime.

• Concatenates strings.

^^^

Bitwise Operators (F#)

• Computes the bitwise exclusive OR operation.

_

Match Expressions (F#)

Generics (F#)

• Indicates a wildcard pattern.

• Specifies an anonymous generic parameter.

`

Automatic Generalization (F#)

• Used internally to indicate a generic type parameter.

{...}

Sequences (F#)

Records (F#)

• Delimits sequence expressions and computation expressions.

• Used in record definitions.

|

Match Expressions (F#)

• Delimits individual match cases, individual discriminated union cases, and enumeration values.

||

Boolean Operators (F#)

• Computes the Boolean OR operation.

|||

Bitwise Operators (F#)

• Computes the bitwise OR operation.

|>

Functions (F#)

• Passes the result of the left side to the function on the right side (forward pipe operator).

~~

Operator Overloading (F#)

• Used to declare an overload for the unary negation operator.

~~~

Bitwise Operators (F#)

• Computes the bitwise NOT operation.

~-

Operator Overloading (F#)

• Used to declare an overload for the unary minus operator.

~+

Operator Overloading (F#)

• Used to declare an overload for the unary plus operator.

as

Right

when

Right

| (pipe)

Left

;

Right

let

Nonassociative

function , fun, match, try

Nonassociative

if

Nonassociative

->

Right

:=

Right

,

Nonassociative

or , ||

Left

& , &&

Left

< op, >op, =, |op, &op

Left

&&& , |||, ^^^, ~~~, <<<, >>>

Left

^ op

Right

::

Right

:?> , :?

Nonassociative

- op, +op, (binary)

Left

* op, /op, %op

Left

** op

Right

f x (function application)

Left

| (pattern match)

Right

prefix operators (+op, -op, %, %%, &, &&, !op, ~op)

Left

.

Left

f(x)

Left

f< types >

Left

October 2010

Added information about equality and inequality operators.

Information enhancement.

April 2011

Added bitwise operators to precedence table.

Customer feedback.