Quick Start¶

Language: Español | English

This guide will help you write your first Crespi program in just a few minutes.

Hello World¶

The simplest program in Crespi:

print("Hello, World!")

Save this to a file hello.crespi and run it.

Crespi offers two ways to execute your code:

Interpreter - Run directly, supports all features
Compiler - Compile to native executable

Output:

Hello, World!

Variables and Constants¶

Use var for values that can change and let for fixed values:

var name = "Maria"
let PI = 3.14159

print(name)     // Maria
print(PI)       // 3.14159

name = "Carlos"   // OK - var can change
// PI = 3.0       // Error! - let cannot change

Basic Data Types¶

// Numbers
var integer = 42
var decimal = 3.14

// Text
var message = "Hello"

// Booleans
var active = true
var inactive = false

// Null
var empty = null

Operators¶

Crespi uses standard symbolic operators:

// Arithmetic
var sum = 5 + 3
var difference = 10 - 4
var product = 6 * 7
var quotient = 20 / 4

// Comparison
var greater = 10 > 5
var equal = 5 == 5

// Logical
var both = true && false   // false
var either = true || false  // true

Conditionals¶

var age = 18

if age >= 18 {
    print("Adult")
} else {
    print("Minor")
}

With multiple conditions:

var grade = 85

if grade >= 90 {
    print("Excellent")
} else if grade >= 70 {
    print("Pass")
} else {
    print("Fail")
}

Loops¶

While¶

var counter = 0

while counter < 5 {
    print(counter)
    counter += 1
}
// Output: 0, 1, 2, 3, 4

For-each¶

var numbers = [1, 2, 3, 4, 5]

for n in numbers {
    print(n * 2)
}
// Output: 2, 4, 6, 8, 10

Functions¶

Basic Syntax¶

fn greet(name) {
    print("Hello, " + name + "!")
}

greet("Ana")  // Hello, Ana!

With Return Value¶

fn square(x) {
    return x * x
}

var r = square(5)
print(r)  // 25

Short Syntax (single expression)¶

fn double(x) = x * 2
fn sum(a, b) = a + b

print(double(7))     // 14
print(sum(3, 4))     // 7

Default Parameters¶

fn greet(name = "World") {
    print("Hello, " + name)
}

greet()         // Hello, World
greet("Ana")    // Hello, Ana

Lists and Dictionaries¶

Lists¶

var fruits = ["apple", "orange", "pear"]

print(fruits[0])           // apple
print(fruits.length())     // 3

fruits.push("grape")
print(fruits)              // [apple, orange, pear, grape]

Dictionaries¶

var person = {
    "name": "Luis",
    "age": 30
}

print(person["name"])   // Luis
person["city"] = "Madrid"
print(person.keys())     // [name, age, city]

Classes¶

class Rectangle(let width, let height) {
    fn area() {
        return this.width * this.height
    }
}

var rect = Rectangle(5, 3)
print(rect.area())  // 15