Windows:

1. Move or copy the executable to a folder of your choice, for example:

   move dist\gladlang.exe "C:\Programs\GladLang"

2. Add that folder to your system PATH:
   • Press Win + R, type sysdm.cpl, press Enter.
   • Go to Advanced → Environment Variables.
   • Under System variables, select Path → Edit → New.
   • Add the full path (e.g., C:\Programs\GladLang).
3. Open a new terminal and test:

   gladlang "test_recursion.glad"

Variables

Variables are assigned using the LET keyword.

LET a = 10
LET b = "Hello"
LET my_list = [a, b, 123]

Numbers

Numbers can be integers or floats. All standard arithmetic operations are supported.

LET math_result = (1 + 2) * 3 # 9
LET float_result = 10 / 4     # 2.5

Strings

Strings are defined with double quotes and support escape characters. They can be concatenated with +.

LET newline = "Hello\nWorld"
LET quoted = "She said, \"This is cool!\""
PRINT "Hello, " + "GladLang"

Lists

Lists are ordered collections of any type. They support indexing, assignment, and concatenation.

LET my_list = [1, "hello", 2 * 3, TRUE]

PRINT my_list[1] # Access: "hello"

LET my_list[1] = "world" # Assign
PRINT my_list[1] # "world"

LET other_list = my_list + [FALSE, 100]

Booleans

Booleans are TRUE and FALSE. They are the result of comparisons and logical operations.

LET t = TRUE
LET f = FALSE
PRINT t AND f # 0 (False)
PRINT t OR f  # 1 (True)
PRINT NOT t   # 0 (False)

Truthiness: 0, 0.0, "", NULL, and FALSE are "falsy." All other values (including non-empty strings, non-zero numbers, lists, functions, and classes) are "truthy."

Null

The NULL keyword represents a null or "nothing" value. It is falsy and prints as 0. Functions with no RETURN statement implicitly return NULL.

Arithmetic & Precedence

^ (power), *, / (division), +, -. Standard operator precedence is respected.

PRINT 1 + 2 * 3   # 7
PRINT (1 + 2) * 3 # 9

Comparison & Logical

• Comparison: ==, !=, <, >, <=, >=
• Logical: AND, OR, NOT

PRINT (10 < 20) AND (10 != 5) # 1 (True)

Increment / Decrement

Supports C-style pre- and post-increment/decrement operators on variables and list elements.

LET i = 5
PRINT i++ # 5
PRINT i   # 6
PRINT ++i # 7
PRINT i   # 7

LET my_list = [10, 20]
PRINT my_list[1]++ # 20
PRINT my_list[1]   # 21

IF Statements

Uses IF...THEN...ENDIF syntax.

LET num = -5
IF num < 0 THEN
  PRINT "It is negative."
ENDIF

WHILE Loops

Loops while a condition is TRUE.

LET i = 3
WHILE i > 0
  PRINT "i = " + i
  LET i = i - 1
ENDWHILE

# Prints:
# i = 3
# i = 2
# i = 1

FOR Loops

Iterates over the elements of a list.

LET my_list = ["apple", "banana", "cherry"]
FOR item IN my_list
  PRINT "Item: " + item
ENDFOR

BREAK and CONTINUE are supported in both WHILE and FOR loops.

Named Functions

Defined with DEF...ENDEF. Arguments are passed by value. RETURN sends a value back.

DEF add(a, b)
  RETURN a + b
ENDEF

LET sum = add(10, 5)
PRINT sum # 15

Anonymous Functions

Functions can be defined without a name, perfect for assigning to variables.

LET double = DEF(x)
  RETURN x * 2
ENDEF

PRINT double(5) # 10

Closures

Functions capture variables from their parent scope.

DEF create_greeter(greeting)
  DEF greeter_func(name)
    # 'greeting' is "closed over" from the parent
    RETURN greeting + ", " + name + "!"
  ENDEF
  RETURN greeter_func
ENDEF

LET say_hello = create_greeter("Hello")
PRINT say_hello("Alex") # "Hello, Alex!"

Recursion

Functions can call themselves.

DEF fib(n)
  IF n <= 1 THEN
    RETURN n
  ENDIF
  RETURN fib(n - 1) + fib(n - 2)
ENDEF

PRINT fib(7) # 13

Classes and Instantiation

Use CLASS...ENDCLASS to define classes and NEW to create instances. The constructor is init.

CLASS Counter
  DEF init(self)
    SELF.count = 0 # 'SELF' is the instance
  ENDEF
  
  DEF increment(self)
    SELF.count = SELF.count + 1
  ENDEF
  
  DEF get_count(self)
    RETURN SELF.count
  ENDEF
ENDCLASS

The SELF Keyword

SELF is the mandatory first argument for all methods and is used to access instance attributes and methods.

LET c = NEW Counter()
c.increment()
PRINT c.get_count() # 1

Inheritance

Use the INHERITS keyword. Methods can be overridden by the child class.

CLASS Pet
  DEF init(self, name)
    SELF.name = name
  ENDEF
  
  DEF speak(self)
    PRINT SELF.name + " makes a generic pet sound."
  ENDEF
ENDCLASS

CLASS Dog INHERITS Pet
  # Override the 'speak' method
  DEF speak(self)
    PRINT SELF.name + " says: Woof!"
  ENDEF
ENDCLASS

LET my_dog = NEW Dog("Buddy")
my_dog.speak() # "Buddy says: Woof!"

Polymorphism

When a base class method calls another method on SELF, it will correctly use the child's overridden version.

CLASS Pet
  DEF introduce(self)
    PRINT "I am a pet and I say:"
    SELF.speak() # This will call the child's 'speak'
  ENDEF
  
  DEF speak(self)
    PRINT "(Generic pet sound)"
  ENDEF
ENDCLASS

CLASS Cat INHERITS Pet
  DEF speak(self)
    PRINT "Meow!"
  ENDEF
ENDCLASS

LET my_cat = NEW Cat("Whiskers")
my_cat.introduce()
# Prints:
# I am a pet and I say:
# Meow!