Syntax & Types

Textwire’s syntax is straightforward and easy to learn. Below are the key rules for writing Textwire code:

• File Extensions: All HTML files intended for Textwire parsing must have a .tw extension.
• Code Placement: All Textwire code must either:
  • Be enclosed within {{ }} braces, or
  • Start with the @ symbol.

Syntax Highlighting

If you use Neovim or VSCode, you can use our Neovim plugin or VSCode extension to get syntax highlighting and other features for Textwire.

Directives

Directives are Textwire statements that begin with the @ symbol. They define layouts, insert content into placeholders, and perform logical operations like conditionals and loops. Directives can only be placed within HTML and cannot be used inside braces ({{ and }}).

Important Notes

• Expressions and Variables: Directives support expressions and variables, such as @if(x == 1) or @use(layoutName).
• Closing Directives: Directives with a body (like @if, @for, @each, and @component) must be closed with the @end keyword.

Read about directives on Directives page.

Escaping

Escape Textwire code by prefixing it with a backslash (\). For example:

<p>\{{ not code }}</p>
<p>\@use("~base")</p>

will be rendered as:

<p>{{ not code }}</p>
<p>@use("~base")</p>

Embedded

Embedded code begins with {{ and end with }}. It is used for defining variables, performing arithmetic operations, conditionally rendering content, and more. Embedded code can be placed anywhere in the file, except within directives.

Important Notes

• Multiple Expressions: Use a semicolon (;) to separate multiple statements/expressions inside braces. For example:

  {{ x = 5; x++; x }}

• Return Values: All embedded code returns a string.

• Defining a variable like {{ x = 5 }} doesn't return anything.

• Expressions like {{ 5 + 5 }} will return a result. In this case, it's "10".

Types and Literals

Textwire has a different type system from Go. When you pass a variable to Textwire, it will be automatically converted to a Textwire type. Here is a list of supported types that you can pass to Textwire or define in Textwire:

Textwire type	Equivalent Go types
string	string
boolean	bool
integer	int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64
float	float32, float64
nil	nil
array	[]string, []bool, []int, []int64, []int32, []int16, []int8, []uint, []uint64, []uint32, []uint16, []uint8, []float64, []float32
object	struct{}, User{}, map[string]string, any struct or map

The biggest difference in types and type literals between Textwire and Go is that Textwire's literals have functions that you can call on them. For example, you can call a split function on a string literal like this: {{ "hello world".split(" ") }} to get an array of strings ["hello", "world"].

Nullable Types

Like Go, each type in Textwire has a nullable version. Here is the table of nullable types:

Type	Empty Literal	Description
string	""	Empty string
integer	0, -0	Zero integer
float	0.0, -0.0	Zero float
boolean	false	False boolean
array	[]	Empty array
object	{}	Empty object
nil	nil	Nil value