# HTML, The Programming Language ## A Programming Language [https://html-lang.org/](https://html-lang.org/) ![width:300px bg right:30%](https://upload.wikimedia.org/wikipedia/commons/6/61/HTML5_logo_and_wordmark.svg) --- # A Sample HTML Program ```html

``` --- # Installation To install HTML, the programming language, download and include the html.js file via a script tag: ```html ``` You may now begin programming in HTML. --- # Getting Started ```html

~~Hello World!~~

``` --- # A more elaborate example of using the value stack would be adding 2 and 3, like so: ```html

``` --- # Comments HTML uses HTML's normal comment mechanism for comments: ```html ``` --- # Literal Values --- # Numbers Numbers can be pushed onto the value stack using the tag: ```html ``` --- # Strings Strings can be pushed onto the value stack using the `` tag. The inner content of the tag will be treated as a string. ```html ~~Hello Strings!~~ ``` --- # Arrays ```html

``` --- # Objects ```html

foo bar

~~Foo~~

``` --- # `true`, `false` & `null` The values `true`, `false` and `null` can all be accessed with the `` command. ```html true ``` --- # Math --- # Addition Addition can be performed with the `
` (add) tag. ```html
``` --- # Subtraction Subtraction can be performed with the `_{` tag.

```html

```

---

# Multiplication

Multiplication can be performed with the `` (mul) tag.

```html

```

---

# Division

Division can be performed with the `` tag.

```html

```

---

# Stack Operations

---

# Duplicate

You can duplicate the value on the top of the stack using the `` (duplicate top) tag.

```html

```

---

# Delete

You can delete/pop the value on the top of the stack using the `` tag.

```html

```

---

# Comparison Operations

---

# Less Than

You can test if a value is smaller than another value by using the `` tag.

```html

```

---

# Greater Than

You can test if a value is smaller than another value by using the `` tag.

```html

```

---

# Equal (Mostly)

You can test if a value is equal (mostly) than another value by using the `` tag.

```html
1

```

---

# Logical Operations

---

# And

You can logically "and" the top two values on the value stack using the `` command.

```html
true

```

---

# Or

You can logically "or" the top two values on the value stack using the `` command.

```html
true
false

```

---

# Invert/Not

You can invert the top value on the value stack using the `` command.

```html
false

```

---

# Control Flow

---

# If (Conditional Execution)

Conditional execution can be achieved by using the `` (if) tag/command.

```html

Yep, 1 == 1

```

---

```html

Yep, 1 == 2

Nope, 1 == 2 isn't true, even in JavaScript

```

---

# Returning

If you wish to return from a function (discussed below) or simply terminate the execution of a program, you may use the `` tag.

```html
This will print...

This will not print...

```

---

# Branching

To execute arbitrary jumps in an HTML, the programming language, you use the anchor tag: ``, by setting the href attribute to the id of the command you wish to jump to.

Here is a loop that will print from 1 to 10:

```html

```

---

# Variables

Variables in HTML, the programming language, are always "local" to the current context.

Global variables, defined in window can be resolved by name, but cannot be written to. (You must use a property access on the window object to do that).

---

# Referencing Variables

You push a variable onto the top of the value stack by using the `` tag.

```html

true

```

---

# Declaring & Setting a Variable

You declare or set (same thing) a variable using the `` tag.

```html

```

---

# I/O

---

# Outputting Values

You can output the top of the stack by using the `` tag.
This will not consume the value.

```html

Hello World!

```

---

# Getting User Input

```html

Nice to meet you,
name

```

---

# Working With Object Properties

---

# Reading Properties

You can read a property of the value on the top of the stack by using the `` (read property) tag.

```html

document

body
```

---

# Setting Properties

You can set a property of an object using the `` (set am property) tag.

```html

document

body

Hello World!

innerHTML
```

---

# Working With Arrays

---

# Reading An Array Value

```html

```

---

# Writing An Array Value

```html

```

---

# Functions

---

# Defining Functions

You can define functions using the `` tag.

```html

```

---

# Invoking Functions

To invoke functions, HTML, the programming language, reuses the `` tag.

```html

```

---

# Invoking Functions On Objects

```html

document

.highlighted

```

---

# JavaScript Integration (Configuring/Extending)

```js
html.meta.commands["pre"] = function(elt, env) {
console.log(env.stack);
}
```

```html

```

---

# Debugging (1/2)

```js
html.meta.debug = function(hdb, elt, env, cmd)
{
// you can set a JavaScript breakpoint here
hdb.break();
}
```

The callback can have up to four parameters:
- `hdb`: The debugger
- `elt`: The element to be executed
- `env`: The current environment (including vars and the value stack)
- `cmd`: The implementation of the command

---

# Debugging (2/2)

You can also invoke one of the following methods on the `hdb` object:
- `step()`: Execute the current instruction and stop before the next one.
- `continue()`: Stop debugging and continue until the next breakpoint (or the program finishes)
- `jumpTo(elt)`: Don't execute the current element, instead jump to the given HTML element

---

# Frequently Asked Questions (1/2)

I have found a bug in HTML, the programming language. What should I do?
> HTML, the programming language, is correct, by definition. The bug therefore is not in the programming language, but rather it is in you.

Is there a specification for HTML, the programming language?
> Yes.

Is HTML a programming language?
> As the name of HTML, the programming language, would suggest, yes, HTML is a programming language.

---

# Frequently Asked Questions (2/2)

Is HTML turing complete?
> Yes.

Is there a shirt?
> Yes.

Why?
> Spieltrieb

No.
> idc

---

# Example (the `N`th fibonnacci number)

```html

num

num

num

num

num

```

---

# End.

> HTML: the programming language is brought to you by big sky software“}