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Operators

 

Table of Contents Sections
  1. Operators Overview
    1. RCL Operator Precedence
  2. Arithmetic Operators
    1. +
    2. -
    3. *
    4. /
    5. %
    6. ^
  3. Collection and Array Operator
    1. <<
    2. [ ]
    3. [ ]=
    4. =~
    5. !~
  4. Relational and Equality Operators
    1. ==, !=
    2. <, <=, >, >=
  5. Logical Operators
    1. &
    2. &&
    3. |
    4. ||
  6. Unary Operators
    1. -
    2. !

Operators Overview

RCL supports a variety of operators for manipulating values and resource collections. There are arithmetic operators for calculations (+, -, *, /, ^, %), collections and array management operators for retrieving and adding elements as well as checking inclusion ([ ], <<, <, >), the usual equality and boolean operators (==, !=, <, >, <=, >=, &, |, !) as well as the regexp operator for match strings with regular expressions (=~, !~).

The following table lists the precedence of RCL operators. Operators are listed top to bottom, in descending precedence.

RCL Operator Precedence

Precedence Operators Notes
0 [] slice operator (retrieve item(s) of array, hash or collection given an index, key or range)
1 ^ exponent
2 !, +, - logical not, unary plus, unary minus
3 *, /, % multiplication, division, modulo
4 +, - addition or string, array or collection concatenation - subtraction or array collection difference
5 << array append
6 ==, !=, =~, !~, >=, <=, >, <  relational and equality operators
7 & bitwise AND
8 | bitwise OR
9 && bitwise AND
10 || logical OR

 

The following sections list all the operators and their semantic depending on the types of the operands. The left column represent the left hand side operand type while the top row represents the right hand side operand type. The values describe the semantic of the operation or list error if the corresponding operator cannot be applied with the given operand types.

Arithmetic Operators

+

+ number string array hash res collection other
number addition error error error error error
string concatenation concatenation error error error error
date/time addition (seconds) error error error error error
array error error concatenation error error error
hash error error error merge left into right error error
res collection error error error error concatenation error
other error error error error error error

-

- number date/time array res collection other
number subtraction error error error error
date/time subtraction (seconds) subtraction (seconds) error error error
array error error array difference error error
res collection error error error coll difference error
other error error error error error

*

* number other
number multiplication error
other error error

/

/ number other
number division (integral if both numbers are integers) error
other error error

%

% number other
number modulo (non integer numbers are rounded) error
other error error

^

^ number other
number power error
other error error

Collection and Array Operator

<<

<< all
array Append object in right hand side to array in left hand side
other error

[ ]

 

The slice operator returns elements of an array, a hash or a resource collection using an index or a range (array and resource collection) or a key (hash). A range is specified using x..y where x and y are optional (no x means from the start of the array or collection, no y means to the end of the array or collection). Note that retrieving elements of a resource collection creates a new resource collection consisting of these elements.

 

[ ] number string range other
res collection Creates new collection consisting of the element at given index. error Creates a new collection consisting of the element in the given range (x..y where x and y are optional) error
array value at given index error Creates a new array consisting of the element in the given range (x..y where x and y are optional) error
hash error value associated with given key if any, 'null' otherwise error error
string Create string composed of character at given index. error Create string made of characters in the given range. Range bounds may have negative values (from last or from beginning). error
other error error error error

[ ]=

 

The slice assign operator replaces an element of an array, hash or resource collection or a range of an array or resource collection with given elements.

 

[ ]= number string range other
res collection Replaces resource at given index. Right hand side must be a resource collection. error Replace elements in the given range with elements of right hand side resource collection. error
array Replace value at given index error Replace elements in the given range with elements of the given array. Right hand side must be an array. error
hash error Replace/set value associated with given key error error
other error error error error

Regular expression/Include Operators

=~

=~ string array other
string 'true' if regular expression given in right operand matches string given in left operand error error
array 'true' if array contains string 'true' if array contains array 'true' if array contains value
hash 'true' if hash has that key error error
other error error error

The right hand side of a regular expression comparison may use the symbol / to delineate the pattern. The ending/ may be followed by the following options:

  • i for case insensitive matching
  • m for multi-line string matching
  • x for extended syntax support (whitespaces in the pattern are ignored)

examples:

"foo" =~ "foo" # true
"foo" =~ /foo/ # true
"foo" =~ /FOO/i #true

!~

a !~ b is equivalent to !(a =~ b)

Relational and Equality Operators

==, !=

Equality comparison is done recursively if values are arrays or hashes.

== all
all 'true' if operands have same value, 'false' otherwise

<, <=, >, >=

< number string date/time res collection array other
number less than error error error error error
string error lexicographical less than error error error error
date/time error error less than error error error
res collection error error error @a < @b: true if all elts of @a are also elts of @b error error
array error error error error $a < $b: true if all elts of $a are also elts of $b error
other error error error error error error


Note:  >, <=, and >=  are omitted for brevity (greater than, lesser or equal than, greater or equal than, respectively).

Logical Operators

&

'Bitwise and'. Applied to resource collections (or arrays) it returns all elements that appear in both resource collections (or arrays).

& 'false' 'null' 'true' array res collection other
'false' 'false' 'false' 'false' 'false' 'false' 'false'
'null' 'false' 'false' 'false' 'false' 'false' 'false'
'true' 'false' 'false' 'true' 'true' 'true' 'true'
array error error error intersection of the two arrays error error
res collection error error error error new collection with common hrefs
-or-
error if collections are of different types		 error
other error error error error error error

&&

'Logical and'. Returns the right hand side operand if the left hand side is neither 'false' nor 'null' (otherwise returns left hand side operand).

&& 'false' 'null' 'true' other (1)
'false' 'false' 'false' 'false' 'false'
'null' 'null' 'null' 'null' 'null'
'true' 'false' 'null' 'true' (1)
other (2)

'false'

 'null' 'true' (2)

|

'Bitwise or'. Applied to resource collections (or arrays), returns all elements that appear in either resource collection (or array).

Note: This operator differs from the + operator when applied to collection in that it will produce only one instance of each element in each collection even if the same element appears in both.

| 'false' 'null' 'true' other
'false' 'false' 'false' 'true' 'true'
'null' 'false' 'false' 'true' 'true'
'true' 'true' 'true' 'true' 'true'
other error error error error

||

'Logical or'. Returns the left hand side operand if it is neither 'false' nor 'null' (otherwise returns right hand side operand).

|| 'false' 'null' 'true' other (2)
'false' 'false' 'null' 'true' (2)
'null' 'false' 'null' 'true' (2)
'true' 'true' 'true' 'true' 'true'
other (1) (1) (1) (1) (1)

Unary Operators

-

- is the unary minus operator:

-  
number opposite value
other error

!

! is the logical not operator. Note that it applies to all types (negating a non boolean value returns 'true' if it is either 'false' or 'null', 'false' otherwise):

!  
'false' 'true'
'null' 'true'
other 'false'
 

 

END

 

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Last modified
15:49, 3 Oct 2014

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