Reserved Operators and Precedence

This lists all the multi-character "punctuation" operators. Note that ... is not an operator.

The operators are sequenced from highest to lowest evaluation priority. Operators grouped together have the same priority. In parenthesis is shown whether an operator appears in front of a value (prefix) or between values (infix). Some operators can be used in both contexts. It also specifies the symbolic name of any method associated with that operator.

Value operators

' '

(p) symbol literal

" "

(p) text literal

yield

(p) yield expression

( )

(p) prioritizes expression to be evaluated as a group

[ ] *[ ] +[ ]

(p) variable declaration

{ }

(p) code block

Term operators

+ new

(p 'new') new instance

.

(i) method call/property access

.:

(i) property access

::

(i '[]') indexed access

( )

(i) method call parameters

[ ]

(i '[]') indexed access

Prefix operators

-

(p '@-') negate

@

(p) Internet resource load

<<

(p '<<') append to 'this'

>>

(p '>>') prepend to 'this'

Arithmetic/Collection operators

**

(i '**') exponent

*

(i '*') multiply

/

(i '/') divide/split

%

(i '%') remainder

+

(i '+') add/concatenate

-

(i '-') subtract

Range operator

..

(i) creates a range

Evaluation operators

==

(i '<=>') equal

!=

(i '<=>') not equal

===

(i) equivalent

~~

(i '~~') match

<=>

(i '<=>') compare (rocketship)

<

(i '<=>') less than

<=

(i '<=>') less than or equal

>

(i '<=>') greater than

>=

(i '<=>') greater than or equal

Evaluation operators

! not

(p) logical not

&& and

(i) logical and

|| or

(i) logical or

Ternary operator

? else

(i) "if .. then .. else ..." expression

Append/Prepend operators

<<

(i '<<') append

>>

(i '>>') prepend

Assignment operators

Note: Within variable declarations, the evaluation priority of ',' and '=' are reversed.

,

(i) value separation

=

(i) assign

:

(i) 'this' property assign

:=

(i) '[]' 'this' index set

+=

(i '+') add in place

-=

(i '-') subtract in place

*=

(i '*') multiply in place

/=

(i '/') divide in place

Async operator

^ async

(p) create asynchronous thread

Line terminator

The semicolon ; is the lowest priority "operator".

Reserved Names

Name tokens are typically used for variables or properties. However, certain names are reserved for special meaning within an Acorn program:

and

logical 'and' operator used in boolean expressions

async

asynchronous operator

baseurl

url of the program's source code

break

terminate a loop block

context

The value of the currently executing execution state

continue

Re-iterate a 'while' or 'for' block

do

A block that performs an automatic '.begin' and '.end'

each

The block for iterating over a collection of values

else

A clause within an 'if' statement

elif

A clause within an 'if' statement

false

The value of 'false'

if

A conditional block or clause

in

A clause within a 'each' block

into

A clause within a 'match/with' block

local

ensures variable(s) are treated as locally scoped

match

Matches a calculated value to several possible values

new

Creates a new instance

null

The value of 'null'

not

logical 'not' operator used in boolean expressions

or

logical 'or' operator used in boolean expressions

return

terminate execution of a method with a return value

self

references the method's self parameter value

selfmethod

the currently executing method or closure

this

The value of the most inclusive 'with' block

true

The value of 'true'

using

clause on this block

wait

A block that waits until all its execution contexts are done.

while

A repetitive block or clause

with

A clause in a 'match' block

yield

suspend a generator with a return value