Operators

Scriggo offers several arithmetic, comparison and logic operators. Since Scriggo is strongly typed, each operator can be used only with specific types, and for binary operators the two operands should have the same type.

As an exception, the three logical operators and, or and not accept any type, and the operands of the contains, not contains and shift operators have specific types but can be different.

Basic operators

These are the basic operators. They are the Go operators and therefore are also available in programs.

For example:

{% if stock > 10 %}
  Wide availability
{% end %}

There are other operator, but they are not discussed in this documentation (see the Go specification).

The following table shows which operators can be used with which type:

And, Or and Not

Scriggo allows to combine any expression with the and, or and not operators and their evaluation returns true or false based on the truth value of their operands.

{% if promotion and stock %} promotion with immediate availability {% end %}

{% if not price %} login to view price {% end %}

The Go language does not have and, or and not, but they are available in Scriggo templates because they make simple if statement conditions easier for non-programmers to read and write.

As an alternative you can use the Go logical operators &&, || and ! that want boolean values as operands. For example, the above examples can be written as:

{% if promotion != nil && stock > 0 %} promotion with immediate availability {% end %}

{% if price == 0  %} login to view price {% end %}

"true" or "false"

For the and, or and not operators all values are true, except for the following values which are false:

See the Scriggo template specification for more details.

Contains

The contains and not contains boolean operators indicates if a slice contains or not contains an element, if a map contains or not contains a key, if a string contains or not contains a substring or a rune (character).

These operators have the following form:

a contains b
a not contains b

The contains operators are specific to Scriggo templates and are not present in the Go language.

Examples

Checks if a slice of strings contains a specific string:

{% var colors = []string{"red", "blue", "yellow", "green"} %}
{% if colors contains "yellow" %}
  colors contains "yellow"
{% end %}

  colors contains "yellow"

Checks if a string contains a substring:

{% if product.Name contains "bundle" %}
  the product's name contains the word "bundle"
{% end %}

  the product's name contains the word "bundle"

Checks if a map contains a key:

{% var nameOf = map[int]string{1: "one", 4: "four", 7: "seven"} %}
{% if nameOf contains 7 %}
  nameOf contains the key 7
{% end %}

  nameOf contains the key 7