Getting Started

Welcome to Tender, a flexible programming language designed for simplicity and power. Let’s dive in!

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1. Variables in Tender

In Tender, variables are defined using the := operator along with var. You don’t need to declare the type explicitly—Tender infers the type based on the assigned value.

Example: Variable Declaration

name := "Alice"    // String variable  
age := 30          // Integer variable  
pi := 3.14         // Floating-point variable  
is_admin := false  // Boolean variable
var year = bigint(2024) //bigint datatype

Reassigning Variables

Variables in Tender are dynamically typed, meaning you can assign a value of a different type to an existing variable.

age = "Thirty"  // Now 'age' holds a String instead of an Integer
println(age)    // Output: Thirty

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2. Data Types

Tender supports several primitive data types:

Type	Example	Description
string	"Hello"	Sequence of characters.
int	42	Whole numbers.
float	-19.84	Numbers with decimal points.
bool	true / false	Logical values.
char	'A'	Single character.
time	time()	time (time.Time in Go)
bigint	bigint(42)	Arbitrary-precision integer.
bigfloat	bigfloat(1000.11)	Arbitrary-precision float.

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3. Arrays and Maps

Arrays

Arrays hold an ordered list of values. They can contain elements of any type.

fruits := ["Apple", "Banana", "Cherry"]  
println(fruits[0])  // Output: Apple

Maps

Maps are key-value pairs, similar to dictionaries in other languages.

person := {name: "Alice", age: 30, is_admin: true}  
println(person["name"])  // Output: Alice

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4. Control Flow Statements

If/Else Statements

Tender supports if/else for decision-making. You can include an init statement before the condition.

if age := 30; age > 18 {
    println("Adult")
}
else {
    println("Minor")
}

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5. Loops

For Loop

The for loop is used to iterate over arrays or perform repeated actions.

numbers := [1, 2, 3, 4]
for i := 0; i < len(numbers); i++ {
    println(numbers[i])
}

For-Each Loop

var fruits = ["mango", "apple", "banana"]

for i, fruit in fruits {
    if fruit == apple {
        continue
    }
    else if fruit i == fruits.length {
        break
    }
    println(fruit)
}

For-condition

for true {
    println(fruit)
}

For-infinity

for {}

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6. Functions in Tender

Functions are defined using the fn keyword. Functions can take arguments and return values.

Defining a Function

greet := fn(name) {
    return "Hello, " + name
}
println(greet("Alice"))  // Output: Hello, Alice

or

fn greet(name) {
    return "Hello, " + name
}
println(greet("Alice"))  // Output: Hello, Alice

Passing Functions as Arguments

Tender supports higher-order functions—functions that take other functions as parameters.

each := fn(arr, action) {
    for x in arr {
        action(x)
    }
}
each([1, 2, 3], fn(n) {
    println(n)
})

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7. Closures

Closures are functions that capture variables from their outer scope.

counter := fn() {
    count := 0
    return fn() {
        count += 1
        return count
    }
}
next := counter()
println(next())  // Output: 1
println(next())  // Output: 2

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8. Recursion and Tail-Call Optimization

Tender supports recursion and optimizes tail-recursive calls for better performance.

factorial := fn(n, acc) {
    if n == 0 {
        return acc
    }
    return factorial(n - 1, acc * n)
}
println(factorial(5, 1))  // Output: 120

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9. Slicing Strings and Arrays

You can extract parts of strings or arrays using slices.

str := "hello world"
println(str[0:5])  // Output: hello

arr := [10, 20, 30, 40, 50]
println(arr[1:4])  // Output: [20, 30, 40]

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10. Type Conversion

Tender provides built-in functions to convert between data types.

str_num := string(42)  // "42"
int_num := int("99")   // 99
float_num := float(3)  // 3.0
bool_val := bool(1)    // true

12. Built-in Functions

Function	Description
println()	Prints output to the console.
len()	Returns the length of an array or string.
append()	Adds elements to an array.
more...

See all builtin functions!

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