Standard Library¶

EasyLang includes a built-in Standard Library that provides essential utilities for:

Mathematics
Strings
Lists
Dictionaries
Type conversion
Random number generation
File handling
Python interoperability
General utility functions

The standard library is composed of:

Python functions wrapped automatically
Built-in functions defined inside the interpreter
EasyLang modules (math.elangh, strings.elangh)
Built-ins added via _wrap_python_module (math, random, etc.)

This chapter documents every major built-in available to EasyLang programs.

Overview of Categories¶

Math Utilities¶

String Utilities¶

List Utilities¶

Dictionary Access¶

Type Conversion¶

Ranges & Iteration Helpers¶

Random Number Utilities¶

Python Interop¶

File Utilities¶

1. Math Functions¶

Math functions come from two sources:

your EasyLang math.elangh
Python’s built-in math module, wrapped into EasyLang

Common functions (EasyLang + Python)¶

Function	Description
`sqrt(x)`	square root
`pow(x, y)`	exponentiation
`sin(x)`	sine
`cos(x)`	cosine
`tan(x)`	tangent
`floor(x)`	round down
`ceil(x)`	round up
`abs(x)`	absolute value
`random()`	float between 0 and 1
`randint(a, b)`	integer between a and b

Example¶

bring math as m
so print m.sqrt(25)
we let x = m.randint(1, 100)

2. String Functions¶

These are provided via your strings.elangh module + built-in wrappers.

Functions

Function	Description
`upper(text)`	convert to uppercase
`lower(text)`	convert to lowercase
`strip(text)`	remove whitespace
`substring(text, start, end)`	extract substring
`contains(text, sub)`	test membership
`startswith(text, sub)`	tests prefix
`endswith(text, sub)`	tests suffix

Usage:

bring strings as s

so print s.upper("hello")
so print s.contains("easy", "sy")

3. List Utilities¶

Lists support several built-in methods automatically mapped by the interpreter.

Methods

Method	Description
`list.push(value)`	append value
`list.pop()`	pop last item
`list.len()`	Length of list
`list.join(separator)`	join with separator

Examples

we let nums = [1, 2, 3]
nums.push(4)
so print nums.len()

4. Dictionary Utilities¶

Dictionaries in EasyLang use attribute access:

Read values

user.name
user.age

Nested dictionaries settings.database.port

Creating dictionaries

we let config = {
    "host": "localhost",
    "port": 8000
}

5. Type Conversion¶

The interpreter provides Python-style conversions:

Function	Meaning
`int(x)`	convert to integer
`float(x)`	convert to floating-point
`str(x)`	convert to string

Examples:

so print int("10")
so print float("3.14")

6. Range & Iteration Helpers¶

range(start, end) generates lists of numbers.

Example:

we let xs = range(1, 5)
so print xs     $ [1, 2, 3, 4]

This is implemented in the interpreter and returns a Python list wrapped in EasyLang.

7. Random Utilities¶

Provided through Python's random module + your math module:

Function	Description
`random()`	returns 0–1 float
`randint(a, b)`	integer in range
`choice(list)`	chooses random item

Example:

bring random as r
we let n = r.randint(1, 10)
so print n

8. Python Interoperability (VERY POWERFUL)¶

This is one of EasyLang’s strongest features. Any Python module can be imported and used like a native EasyLang module.

Example:

bring os as o
so print o.getcwd()

Install a package using ELPM: elpm --install requests

Now use in EasyLang:

bring requests as req
we let r = req.get("https://httpbin.org/get")
so print r.text

Every Python function, method, and property is wrapped automatically.

9. File Utilities (Built-in Keywords)¶

These are technically statements, but they act like part of the standard library:

Keyword	Meaning
`open file as f for read`	open file
`open file as f for write`	create/overwrite
`writeline f with text`	write a line
`readline f into var`	read a line
`close f`	close file

Example:

open "out.txt" as f for write
    writeline f with "EasyLang!"
close f

10. Built-in Operators (English + Symbol Forms)¶

Arithmetic

plus (+)
minus (-)
mul (*)
div (/)

Comparison

equals (==)
not equals (!=)
less (<)
greater (>)
>= <=

Logic

and
or
not

These are implemented directly in the parser.

11. Utility Functions (from Python built-ins)¶

The interpreter exposes:

len(x) → list/string length
type(x) → type name
print(x) → raw Python print (rarely needed)

Example: so print len([1, 2, 3])

Summary¶

The EasyLang Standard Library includes:

math operations (EasyLang + Python math)
string utilities
list methods
dictionary access via dot notation
type conversion functions
range generation
random utilities
Python module interoperability
built-in file I/O system
a wide variety of helper functions

The Standard Library allows EasyLang to be expressive, readable, and powerful while keeping syntax simple and English-like.

Next Steps¶

Continue to Error System to learn how Error System work in detail