import strformat

type
  Person = object
    name: string
    age: Natural # Ensures the age is positive

let people = [
  Person(name: "John", age: 45),
  Person(name: "Kate", age: 30)
]

for person in people:
  # Type-safe string interpolation,
  # evaluated at compile time.
  echo(fmt"{person.name} is {person.age} years old")


# Thanks to Nim's 'iterator' and 'yield' constructs,
# iterators are as easy to write as ordinary
# functions. They are compiled to inline loops.
iterator oddNumbers[Idx, T](a: array[Idx, T]): T =
  for x in a:
    if x mod 2 == 1:
      yield x

for odd in oddNumbers([3, 6, 9, 12, 15, 18]):
  echo odd


# Use Nim's macro system to transform a dense
# data-centric description of x86 instructions
# into lookup tables that are used by
# assemblers and JITs.
import macros, strutils

macro toLookupTable(data: static[string]): untyped =
  result = newTree(nnkBracket)
  for w in data.split(';'):
    result.add newLit(w)

const
  data = "mov;btc;cli;xor"
  opcodes = toLookupTable(data)

for o in opcodes:
  echo o

var conditional = 42

if conditional < 0:
  echo "conditional < 0"
elif conditional > 0:
  echo "conditional > 0"
else:
  echo "conditional == 0"

var ternary = if conditional == 42: true else: false

var another =
  if conditional == 0:
    "zero"
  elif conditional mod 2 == 0:
    "even"
  else:
    "odd"


# Case switch.
var letter = 'c'

case letter
of 'a':
  echo "letter is 'a'"
of 'b', 'c':
  echo "letter is 'b' or 'c'"
of 'd'..'h':
  echo "letter is between 'd' and 'h'"
else:
  echo "letter is another character"

import math

# Basic math.
assert 1 + 2 == 3        # Sum
assert 4 - 1 == 3        # Substraction
assert 2 * 2 == 4        # Multiplication
assert 4 / 2 == 2.0      # Division
assert 4 div 2 == 2      # Integer Division
assert 2 ^ 3 == 8        # Power
assert 4 mod 2 == 0      # Modulo
assert (2 xor 4) == 6    # XOR
assert (4 shr 2) == 1    # Shift Right
assert PI * 2 == TAU     # PI and TAU
assert sqrt(4.0) == 2.0  # Square Root
assert round(3.5) == 4.0 # Round
assert isPowerOfTwo(16)  # Powers of Two
assert floor(2.9) == 2.0 # Floor
assert ceil(2.9) == 3.0  # Ceil
assert cos(TAU) == 1.0   # Cosine
assert gcd(12, 8) == 4   # Greatest common divisor
assert trunc(1.75) == 1.0     # Truncate
assert floorMod(8, 3) == 2    # Floor Modulo
assert floorDiv(8, 3) == 2    # Floor Division
assert hypot(4.0, 3.0) == 5.0 # Hypotenuse
assert gamma(4.0) == 6.0      # Gamma function
assert radToDeg(TAU) == 360.0 # Radians to Degrees
assert clamp(1.4, 0.0, 1.0) == 1.0 # Clamp

import strutils

assert "con" & "cat" == "concat"
assert "    a    ".strip == "a"
assert "42".parseInt == 42
assert "3.14".parseFloat == 3.14
assert "0x666".parseHexInt == 1638
assert "TrUe".parseBool == true
assert "0o777".parseOctInt == 511
assert "a".repeat(9) == "aaaaaaaaa"
assert "abc".startsWith("ab")
assert "abc".endsWith("bc")
assert ["a", "b", "c"].join == "abc"
assert "abcd".find("c") == 2
assert "a x a y a z".count("a") == 3
assert "A__B__C".normalize == "abc"
assert "a,b".split(",") == @["a", "b"]
assert "a".center(5) == "  a  "
assert "a".indent(4) == "    a"
assert "    a".unindent(4) == "a"

for word in tokenize("This is an example"):
  echo word

import sugar, tables, sets

let variable0 = collect(newSeq):
  for item in @[-9, 1, 42, 0, -1, 9]:
    item * 2

assert variable0 == @[-18, 2, 84, 0, -2, 18]

let variable1 = collect(initTable):
  for key, value in @[0, 5, 9]:
    {key: value div 2}

assert variable1 == {0: 0, 1: 2, 2: 4}.toTable

let variable2 = collect(initHashSet):
  for item in @[-9, 1, 42, 0, -1, 9]:
    {item + item}

assert variable2 == [2, 18, 84, 0, -18, -2].toSet