Understanding Verse Expressions

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Verse, the modern multi-paradigm programming language, offers a variety of powerful features that make it an attractive choice for developers. One of the key elements of Verse is its expressive syntax, which enables programmers to create concise and readable code. In this guide, we will explore the concept of expressions in Verse, discussing their structure, types, and usage in creating efficient and maintainable code.

What are Expressions in Verse?

In Verse, expressions are fundamental building blocks of code that represent values or operations. They can be simple literals, like numbers or strings, or more complex constructs, like function calls or arithmetic operations. The primary purpose of expressions is to produce a value, which can then be assigned to a variable, used as an argument in a function call, or combined with other expressions to create more complex constructs.

Types of Expressions in Verse

Verse offers a rich variety of expression types that allow developers to create diverse and powerful code. Some of the most common expression types include:

1. Literal Expressions

Literal expressions represent fixed values, such as numbers, strings, or booleans. These expressions are used to define constant values within the code:

number = 42
text = "Hello, World!"
flag = true

2. Variable Expressions

Variable expressions refer to the value stored in a variable. They are used to access or modify the contents of a variable during program execution:

counter = 0
counter = counter + 1
message = "Current count: " + counter.toString()

3. Arithmetic Expressions

Arithmetic expressions perform mathematical operations on numeric values. They support addition, subtraction, multiplication, division, and modulo operations, among others:

result = (10 + 5) * 3 - 2 / 4
remainder = 9 % 4

4. Comparison Expressions

Comparison expressions evaluate the relationship between two values, producing a boolean result. These expressions use comparison operators such as less than, greater than, equal to, and not equal to:

isEqual = 5 == 5
isGreater = 7 > 3
isNotEqual = "apple" != "banana"

5. Logical Expressions

Logical expressions perform boolean operations on values, such as AND, OR, and NOT. These expressions are used to create complex conditional statements and control the flow of the program:

isTrue = true && false
isFalse = true || false
isNotTrue = !true

6. Function Calls

Function call expressions invoke a function, passing arguments if necessary, and return the result of the function execution. These expressions allow developers to modularize code, reuse logic, and create more maintainable programs:

function square(x) {
    return x * x

result = square(5) // result will be 25

7. Conditional Expressions

Conditional expressions use a ternary operator to evaluate a condition and produce a value based on whether the condition is true or false. This allows for concise and readable code when choosing between two values:

value = 42
description = (value > 10) ? "Large number" : "Small number"

Combining Expressions

Verse expressions can be combined to create more complex constructs and perform intricate operations. By nesting expressions within one another, developers can create sophisticated logic with concise and readable code:

function distance(x1, y1, x2, y2) {
    return Math.sqrt(square(x2 - x1) + square(y2 - y1))

result = distance(3, 4, 7, 9) // result will be 5.830951894845301

In this example, we combine function call, arithmetic, and conditional expressions to create a complex expression that calculates the distance between two points in a two-dimensional plane.

Table of Expressions

Check out the documentation here.

Expression Description Is the Expression Failable?
Literals A literal is a fixed value in your code, such as a number or a character. In Verse, there are literals for the following types:
Function Calls A function call is an expression, and can have two forms: FunctionName() and FunctionName[]. The result type of the function call expression is defined in the function signature. Refer to Function for more details. Only when the function call has the form FunctionName[], and the function definition has the <decides> specifier.
Comparison A comparison expression compares two things using one of the comparison operators:
Refer to Operators for more details.
Assignment An assignment expression stores a value at a mutable location, such as when initializing a constant or changing the value of a variable. Refer to Variables and Constants for more details.
Math A math expression performs computations using the operators:

All of these operators also have assignment variants that can be used with pointers. Refer to Operators for more details.
Only for integer division.
Decision A decision expression uses the operators not, and, and or to give you control over the success and failure decision flow. Refer to Operators for more details. Yes
Query A query expression uses the operator ? and checks whether a logic or option value is true. Otherwise, the expression fails. Refer to Operators for more details. Yes
Class and Struct Instantiation Creating an instance of a class or struct is an expression. Refer to Class and Struct.
Control Flow Control flow is the order in which
a computer executes instructions. You can use expressions such as if and loop to change that flow. Some control flow expressions, such as loop, only return void and so may not be useful everywhere you can use an expression. The following are control flow expressions in Verse:
Refer to Control Flow for more details.
Array An array is a container where you can store elements of the same type. The elements of an array are in the order you insert them into the array, and you can access the elements by their position in the array, called their index. For more info, see Array. Only when indexing into an array.
Tuple A tuple is a container where you can store elements of one or more types. The elements of a tuple are in the order you insert them into the tuple and you can access the elements by their position in the tuple, called their index. For more info, see Tuple.
Map A map is a container where you can store values associated with another value, called key-value pairs. Key-value pairs can be any combination of types as long as the key type is comparable. The elements of a map are in the order you insert the key-value pairs into the map, and you can access the elements by their unique keys. For more info, see Map.
Option An option is a container that can have one or no value of a type. For more info, see Option.
Range Range expressions contain all the numbers between and including the two specified values with .. between, for example 1..5. Range expressions can only be used in some places, such as in for expressions. See Range for more details.


Expressions are a powerful and versatile feature of the Verse programming language, enabling developers to create efficient, maintainable, and expressive code.

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