feat: begin to cascade folders

src/layouts/NewDocsLayout.astro

@@ -49,6 +49,40 @@ const posts_2 = posts
 	}))
 	.sort((p1, p2) => p1.frontmatter.order > p2.frontmatter.order? 1 : -1);
 
+// build a hierarchy of the files
+const second_level: Record<string, Array<AstroFile>> = {
+	"_": [],
+};
+for (const post of posts_2) {
+	const fragments = post.path.split("/");
+	if (fragments.length === 3) {
+		const folder_name = fragments[1];
+		// create if not exists
+		if (second_level[folder_name] === undefined) {
+			second_level[folder_name] = [];
+		}
+		second_level[folder_name].push(post);
+	}
+	else if (fragments.length === 2) {
+		// add to root folder
+		second_level["_"].push(post);
+	}
+}
+
+console.log(JSON.stringify(second_level, null, 4));
+
+// transform to the layout that the sidebar expects
+
+const entries = [];
+for (const levels_key in second_level) {
+	if (levels_key === "_") {
+		// top level
+		const posts = second_level[levels_key];
+		entries.push(...posts)
+	}
+}
+
+
 const index_page = posts_2.find(post => post.relative_file === "/index.md" || post.relative_file === "/index.mdx");
 const basePath = index_page.url;
 
@@ -68,7 +102,7 @@ const pagesIndex = posts_2;
         >
             <nav class="py-4 pr-2 overflow-x-scroll h-[calc(100vh-3rem)]">
                 {
-                    pagesIndex.map((entry) => (
+                    entries.map((entry) => (
                         <Sidebar entry={entry} basePath={basePath} />
                     ))
                 }

src/pages/en/latest/learn/basics.mdx

@@ -1,13 +0,0 @@
----
-layout: "./_wrapper.astro"
-title: Basics
-order: 2
----
-import InteractiveCode from "@/components/InteractiveCode.astro";
-import Code from "@/components/Code.astro"
-
-# Hello!
-
-Hi
-
-

src/pages/en/latest/learn/basics/comments.mdx

@@ -0,0 +1,62 @@
+---
+layout: "../_wrapper.astro"
+title: Comments
+order: 2
+---
+import Code from "@/components/Code.astro"
+
+# Comments
+
+THP supports single and multi line comments:
+
+
+## Single line
+
+Begin with double slash `//` and continue until the end of the line.
+
+<Code thpcode={`
+// This is a single line comment
+print("hello!")
+
+print("the result is {5 + 5}") // This will print 10
+`} />
+
+
+## Multi line
+
+These begin with `/*` and end with `*/`. Everything in between is ignored.
+
+Multi line comments can be nested in THP.
+
+<Code thpcode={`
+/*
+    This is a
+    multiline comment
+*/
+`} />
+
+<Code thpcode={`
+/*
+    Multiline comments
+    can be /* nested */
+*/
+`} />
+
+## Documentation comments
+
+Documentation comments use triple slashes `///`.
+These use [CommonMark Markdown](https://commonmark.org/) syntax.
+
+<Code thpcode={`
+/// Transforms the format from A to B...
+///
+/// ## Errors
+///
+/// This function will error if condition
+/// X or Y is met...
+fun transform() {
+    // ...
+}
+`} />
+
+

src/pages/en/latest/learn/basics/datatypes.mdx

@@ -0,0 +1,87 @@
+---
+layout: "../_wrapper.astro"
+title: Datatypes
+order: 4
+---
+import Code from "@/components/Code.astro"
+
+# Datatypes
+
+THP requires that all datatypes start their name with an
+uppercase letter.
+
+The following are basic datatypes.
+
+## Int
+
+Same as php int
+
+<Code thpcode={`
+Int age = 32
+// Hexadecimal numbers start with 0x
+Int red = 0xff0000
+// Octal numbers start with 0o
+Int permissions = 0o775
+// Binary numbers start with 0b
+Int char_code = 0b01000110
+
+// IMPORTANT!
+// Since Octal starts with \`0o\`, using just a leading 0
+// will result in a decimal!
+Int not_octal = 032     // This is 32, not 26
+`} />
+
+// TODO: Make it a compile error to have leading zeroes,
+and force users to use `0o` for octal
+
+
+## Float
+
+Same as php float
+
+
+<Code thpcode={`
+Float pi = 3.141592
+Float light = 2.99e+8
+`} />
+
+
+## String
+
+THP strings use **only** double quotes. Single quotes are
+used elsewhere.
+
+<Code thpcode={`
+String name = "Rose"
+`} />
+
+Strings have interpolation with `{}`.
+
+<Code thpcode={`
+print("Hello, {name}")      // Hello, Rose
+`} />
+
+Unlike PHP, THP strings are concatenated with `++`, not with `.`.
+This new operator implicitly converts any operator into a string.
+
+<Code thpcode={`
+val name = "John" ++ " " ++ "Doe"
+val greeting = "My name is " ++ name ++ " and I'm " ++ 32 ++ " years old"
+`} />
+
+The plus operator `+` is reserved for numbers.
+
+
+## Bool
+
+THP booleans are `true` and `false`. They are case sensitive,
+**only lowercase.**
+
+<Code thpcode={`
+Bool is_true = true
+Bool is_false = false
+
+// This is a compile error
+val invalid = TRUE
+`} />
+

src/pages/en/latest/learn/basics/hello-world.mdx

@@ -0,0 +1,46 @@
+---
+layout: "../_wrapper.astro"
+title: Hello world
+order: 1
+---
+import InteractiveCode from "@/components/InteractiveCode.astro";
+import Code from "@/components/Code.astro"
+
+# Hello, world!
+
+## THP source code
+
+Unlike PHP, THP code is written directly. There is no need to use any `<?php` tags,
+just write the code like any other programming language.
+
+As a consequence of this, HTML templates are defined in other ways, which will be
+detailed later on.
+
+To write a hello world program write the following code in a file:
+
+<Code thpcode={`
+print("Hello, world!")
+`} />
+
+Then run `thp hello.thp` from your terminal.
+
+
+## Instruction separation
+
+THP uses whitespace to determine when a statement is over. In short,
+where PHP uses a semicolon `;`, THP uses a newline.
+
+```php
+echo("A");
+echo("B");
+echo("C");
+```
+
+<Code thpcode={`
+print("A")
+print("B")
+print("C")
+`} />
+
+As a consequence of this, there can only be 1 statement per line.
+

src/pages/en/latest/learn/basics/operators.mdx

@@ -0,0 +1,121 @@
+---
+layout: "../_wrapper.astro"
+title: Operators
+order: 5
+---
+import Code from "@/components/Code.astro"
+
+# Operators
+
+
+Most of the PHP operators are present in THP.
+
+## Numbers
+
+<Code thpcode={`
+var number = 322
+
+number + 1
+number - 1
+number * 1
+number / 1
+number % 2
+
+number += 1
+number -= 1
+number *= 1
+number /= 1
+number %= 2
+`} />
+
+**There are no prefix/postfix increment operators** (`++`, `--`),
+use `+=` or `-=` instead.
+
+<Code thpcode={`
+// Use
+number += 1
+
+// instead of
+number++   // This is a compile error
+`} />
+
+### Comparison
+
+These operators will not do implicit type conversion. They can
+only be used with same datatypes.
+
+<Code thpcode={`
+v1 < v2
+v1 <= v2
+v1 > v2
+v1 >= v2
+`} />
+
+There is only `==` and `!=`. They are equivalent to `===` and `!==`.
+
+<Code thpcode={`
+v1 == v2
+v1 != v2
+`} />
+
+
+### Bitwise
+
+TBD
+
+<Code thpcode={`
+number and 1
+number or 2
+number xor 1
+number xand 1
+`} />
+
+## Strings
+
+Strings **do not use `.`** for concatenation. They use `++`.
+
+<Code thpcode={`
+"Hello " ++ "world."
+`} />
+
+This new operator **implicitly converts** types to string
+
+<Code thpcode={`
+"Hello " ++ 322      // 322 will be converted to "322"
+`} />
+
+
+## Boolean
+
+These operators work **only with booleans**, they do not perform
+type coercion.
+
+<Code thpcode={`
+c1 && c2
+c1 || c2
+`} />
+
+## Ternary
+
+There is no ternary operator. See [Conditionals](/learn/flow-control/conditionals) for alternatives.
+
+
+## Null
+
+These are detailed in their section: [Nullable types](/learn/error-handling/null)
+
+<Code thpcode={`
+val person = some_fun()
+
+person?.name
+person?.name ?? "Jane"
+person?.greet?.()
+
+if person?
+{
+    person.name
+}
+`} />
+
+
+

src/pages/en/latest/learn/basics/variables.mdx

@@ -0,0 +1,98 @@
+---
+layout: "../_wrapper.astro"
+title: Variables
+order: 3
+---
+import Code from "@/components/Code.astro"
+
+# Variables
+
+THP distinguishes between mutable and immutable variables.
+
+Variables must be declared in THP to avoid issues with scoping and
+to know if they are mutable/immutable.
+It's a compile error to use undeclared variables.
+
+Variable names **don't** start with a dollar sign `$`.
+
+Variable names **must** begin with a lowercase letter or an underscore.
+Then they may contain lowercase/uppercase letters, numbers and underscores.
+
+As a regex: `[a-z_][a-zA-Z0-9_]*`
+
+## Immutable variables
+
+Defined with `val`, followed by a variable name and a value.
+
+<Code level={2} thpcode={`
+val surname = "Doe"
+val year_of_birth = 1984
+`} />
+
+It's a compile error to attempt to modify it
+
+<Code level={2} thpcode={`
+val surname = "Doe"
+surname = "Dane"    // Error
+`} />
+
+
+
+### Datatype annotation
+
+Written after the `val` keyword but before the variable name.
+
+<Code level={2} thpcode={`
+val String surname = "Doe"
+val Int year_of_birth = 1984
+`} />
+
+When annotating an immutable variable the `val` keyword is optional
+
+<Code level={2} thpcode={`
+// Equivalent to the previous code
+String surname = "Doe"
+Int year_of_birth = 1984
+`} />
+
+This means that if a variable only has a datatype, it is immutable.
+
+It is a compile error to declare a variable of a datatype,
+but use another.
+
+<Code level={2} thpcode={`
+// Declare the variable as a String, but use a Float as its value
+String capital = 123.456
+`} />
+
+
+## Mutable variables
+
+Defined with `var`, followed by a variable name and a value.
+
+<Code level={2} thpcode={`
+var name = "John"
+var age = 32
+
+age = 33
+`} />
+
+### Datatype annotation
+
+Written after the `var` keywords but before the variable name.
+
+<Code level={2} thpcode={`
+var String name = "John"
+var Int age = 32
+`} />
+
+When annotating a mutable variable the keyword `var` is still **required**.
+
+<Code level={2} thpcode={`
+// Equivalent to the previous code
+var String name = "John"
+var Int age = 32
+`} />
+
+
+