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Data Types in Flow-Wing

1. Integer Data Type (int)​

int stores a 32-bit signed integer — whole numbers, no fractional parts.

Example Usage:​

var x: int = 42

Properties:​

  • Range: -2,147,483,648 to 2,147,483,647
  • Default Value: 0
  • Usage: Counting, indexing, and simple arithmetic.

2. Decimal Data Type (deci)​

deci stores floating-point numbers — values with a decimal point.

Example Usage:​

var y: deci = 3.14

Properties:​

  • Precision: deci is 64-bit (double precision). Use deci32 (32-bit, single precision) only when memory is tight.
  • Usage: Financial calculations, scientific computations, and anywhere decimal precision matters.

3. Boolean Data Type (bool)​

bool holds one of two values: true or false. Think of it as an on/off switch with a name.

Example Usage:​

var isActive: bool = true

Properties:​

  • Values: true or false
  • Usage: Conditions, flags, and toggles.

4. String Data Type (str)​

str stores a sequence of characters — text, in other words.

Example Usage:​

var name: str = "flowwing"
print(name, name[2])

Properties:​

  • Usage: Text processing, messages, and any form of textual data.

String Indexing​

Strings are 0-indexed. name[i] returns a char at position i:

var name: str = "Flow"
print(name[0])  /; 'F'
print(name[3])  /; 'w'

5. Nothing Data Type (nthg)​

nthg marks the absence of a value. Use it as the return type for functions that don't return anything — no surprise, no data.

Example Usage:​

fun doNothing() -> nthg {
  /; This function returns nothing
}

Properties:​

  • Usage: Return type for procedures (functions with no return value).

6. 32-bit Decimal Data Type (deci32)​

deci32 is a 32-bit floating-point number — half the precision of deci, half the memory.

Example Usage:​

var z: deci32 = 1.23f

Properties:​

  • Precision: 32-bit (single precision) — lower than deci
  • Usage: Memory-constrained contexts where full double precision isn't worth the cost.

7. 8-bit Integer Data Type (int8)​

int8 is a compact 8-bit signed integer — small numbers in a small footprint.

Example Usage:​

var x: int8 = Int8(42)

Properties:​

  • Range: -128 to 127
  • Usage: Memory-tight contexts with values that fit in one byte. Convert from int with Int8().

8. Null (null)​

null is the keyword for "no value." Compare with == null, != null, or assign null where a reference or optional value might be empty.

Example usage​

var n = null
print(null == null, "\n")

Properties​

  • Usage: Absence of a value — object references, optional fields, and other nullable shapes.

See the File Handling Module for real-world null and Err patterns.

9. 64-bit Integer Data Type (int64)​

int64 stores a 64-bit signed integer — for when 32 bits aren't enough. Append the l suffix to literals to explicitly create an int64 value.

Example Usage:​

var big: int64 = 10000000000l
var small: int64 = -42l

Properties:​

  • Range: -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
  • Default Value: 0
  • Literal suffix: l (e.g., 100l, -1l)
  • Usage: Large counters, timestamps, file sizes — anywhere 32 bits would overflow.

10. Character Data Type (char)​

char holds a single Unicode character. Write it in single quotes — yes, even emojis.

Example Usage:​

var letter: char = 'A'
var emoji: char = '🚀'
print(letter, " ", emoji)

Properties:​

  • Literal syntax: Single-quoted: 'a', '9', 'ñ', '🚀'
  • Escape sequences: \n, \t, \', \\
  • Conversion: Use Char(65) to convert an integer codepoint, or Char("X") to grab the first character of a string.
  • Usage: Individual characters, text processing, codepoint arithmetic.

11. Dynamic Type (dyn / unknown)​

Declare a variable without a type annotation and Flow-Wing gives you a dynamic variable. The keyword unknown is the compile-time type for these values. A dynamic variable holds any value and can change its type at runtime — like a box that reshapes itself to fit whatever you put in.

Example Usage:​

var x = 42       /; x is dyn, currently holds int
print(x + 1)     /; 43 — works, x acts as int
x = "hello"      /; x now holds str
print(x + "world")  /; helloworld — works, x acts as str

Properties:​

  • Declaration: var name = value — no type annotation needed
  • All operations work dynamically: +, -, *, /, %, ==, !=, <, <=, >, >=, &&, ||, !, ~
  • Type conversions: Use Int32(), String(), Decimal(), Bool(), Char(), Int64(), Int8(), Decimal32() to explicitly convert
  • Usage: Scripting-style code, heterogeneous collections, prototyping.