docs: update README

README.md

@@ -6,51 +6,57 @@ Advent of Code 2024.
 
 For the language to be almost operational it should have:
 
-- an interpreter,
-- syntax highlighting,
-- basic LSP.
+- [x] an interpreter,
+- [ ] syntax highlighting,
+- [ ] basic LSP.
 
-## Wishlist:
+## Usage
+
+1. Clone this repository:
+   ```sh
+   git clone https://github.com/viddrobnic/aoc-lang.git
+   ```
+2. Build and install the interpreter:
+   ```sh
+   cd aoc-lang
+   cargo install --path .
+   ```
+3. Run some code:
+   ```sh
+   aoc-lang examples/hello_world.aoc
+   ```
+
+## Language features
+
+AoC language supports the following features:
 
-### Language features:
-
-- [x] integers
-  - from float
-  - from string
-- [x] floats
-  - from int
-  - from string
-- [x] booleans
-  - from string
-- [x] strings
-  - concatenate
-  - append
-  - split
-- [x] arrays
-  - concatenate
-  - push
-  - pop
-  - unpacking via assignment: `[a, b] = [42, "foo"]`
-- [x] hash maps
-  - add
-  - remove
-- [x] arithmetic operations (`+`, `-`, `*`, `/`, `%`)
-- [x] bit-wise operations (`&`, `|`, `!`)
-- [x] comparison operations (`<`, `>`, `<=`, `>=`, `==`, `!=`)
-- [x] logical operations (`!`, `&`, `|`)
-- [x] variables
-- [x] if/else statements
-- [x] while loop
-- [x] for loop
-- [x] break
-- [x] continue
-- [x] functions
-  - return
-  - recursion
-- [x] comments
-- [x] stdin, stdout
-- [x] imports
-- [x] error reporting with line numbers
+- integers
+- floats
+- booleans
+- strings:
+- arrays
+- hash maps
+- arithmetic operations (`+`, `-`, `*`, `/`, `%`)
+- bit-wise operations (`&`, `|`, `!`)
+- comparison operations (`<`, `>`, `<=`, `>=`, `==`, `!=`)
+- logical operations (`!`, `&`, `|`)
+- variables
+- multi variable assignment (`[a, b] = [10, 20]`)
+- if/else statements
+- while loop
+- for loop
+- break
+- continue
+- functions
+- comments
+- stdin, stdout
+- imports
+- error reporting with line numbers
+
+For more detailed overview of the syntax, see `examples` directory,
+which contains examples of code with comments.
+
+## Wishlist:
 
 ### Syntax highlighting
 

examples/aoc_day_01.aoc

@@ -0,0 +1,96 @@
+// Solution for day 01 of advent of code 2024
+// https://adventofcode.com/2023/day/1
+//
+// Run it as:
+// aoc-lang examples/aoc_day_01.aoc < input
+
+// Read input
+data = []
+for (line = input(); line; line = input()) {
+    push(data, line)
+}
+
+// Part one
+res = 0
+for (i = 0; i < len(data); i = i + 1) {
+    chars = split(data[i], "")
+    n = 0
+
+    // First number
+    for (j = 0; j < len(chars); j = j + 1) {
+        if (int(chars[j])) {
+            n = int(chars[j])
+            break
+        }
+    }
+
+    // Last number
+    for (j = len(chars) - 1; j >= 0; j = j - 1) {
+        if (int(chars[j])) {
+            n = n * 10 + int(chars[j])
+            break
+        }
+    }
+
+    res = res + n
+}
+
+print("Part one: " + str(res))
+
+// Part two
+substr_is = fn(target_ch, position, lookup_ch) {
+    if (position + len(lookup_ch) > len(target_ch)) {
+        return false
+    }
+
+    for (i = 0; i < len(lookup_ch); i = i + 1) {
+        if (target_ch[position + i] != lookup_ch[i]) {
+            return false
+        }
+    }
+
+    return true
+}
+
+digits = ["one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten"]
+digit = fn(chars, position) {
+    if (int(chars[position])) {
+        return int(chars[position])
+    }
+
+    for (d = 0; d < len(digits); d = d + 1) {
+        if (substr_is(chars, position, split(digits[d], ""))) {
+            return d + 1
+        }
+    }
+}
+
+
+res = 0
+for (i = 0; i < len(data); i = i + 1) {
+    chars = split(data[i], "")
+    n = 0
+
+    // First number
+    for (j = 0; j < len(chars); j = j + 1) {
+        d = digit(chars, j)
+        if (d) {
+            n = d
+            break
+        }
+
+    }
+
+    // Last number
+    for (j = len(chars) - 1; j >= 0; j = j - 1) {
+        d = digit(chars, j)
+        if (d) {
+            n = n * 10 + d
+            break
+        }
+    }
+
+    res = res + n
+}
+
+print("Part two: " + str(res))

examples/fibonacci.aoc

@@ -0,0 +1,15 @@
+// Recursive fibonacci function implementation,
+// which also uses a for loop to print the first
+// 10 number in the sequence.
+
+fib = fn(n) {
+    if (n <= 2) {
+        return 1
+    } else {
+        fib(n-1) + fib(n-2)
+    }
+}
+
+for (i = 1; i <= 10; i = i + 1) {
+    print(fib(i))
+}

examples/hello_world.aoc

@@ -0,0 +1,3 @@
+print("What is your name?")
+name = input()
+print("Hello " + name + "!")