# Introduction

WLang inspires from Mustache and encourages you to write logic-less templates. It does not mean that imperative constructions are not needed. Iterations and conditional sections, in particular are definitely something required.

## Conditional and inverted sections

* question (?) provides a if-then-else section, with optional else
* caret    (^) provides a if-else-then section, with optional then

The boolean evaluation is based on Ruby's conditions and has the same semantics: nil and false are FALSE, all other values are TRUE. For instance,

    'Hello TRUE'   renders as 'Hello TRUE'
    'Hello TRUE' renders as 'Hello TRUE'
    'Hello FALSE'  renders as 'Hello FALSE'
    'Hello FALSE'    renders as 'Hello FALSE'

For inverted sections,

    'Hello FALSE'   renders as 'Hello FALSE'
    'Hello FALSE' renders as 'Hello FALSE'
    'Hello TRUE'  renders as 'Hello TRUE'
    'Hello TRUE'    renders as 'Hello TRUE'

In both cases, the first block relies on an expression evaluation and therefore allows dotted expressions (see 1-basics.md), while also recognizing high-level constructs. Also, the third block is optional. As an example,

    'Hello world' renders as 'Hello world' if `vart` contains 'true'

whereas,

    'Hello ' renders as 'Hello ' if `varf` contains 'false'

As usual, use it with parcimony and care but enjoy its powerfulness.

## Iterations

A special tag allows you to perform simple iterations. More accurately, the star allows you to render a block for each value of a sequence, joining the results with an optional separator:

* star (*) joins the rendering of its second block for each element of a sequence

For instance,

    <ul>
      <li>Bernard</li>
      <li>Louis</li>
    </ul>

Renders an HTML list with the authors names. A separator can be specified through the third optional block:

    Bernard, Louis

Will render 'Bernard, Louis'.