values.md

Values

Builting types

Nil

The nil value is a special value indicating the absence of a value. It is the only instance of the Nil type.

Booleans

A boolean represant a binary value, true and false are the only possible instances of the Bool type.

Integer numbers

Integer numbers and floating point numbers have distinc types in Tx.

Integer numbers are instances of the Int type. And integer numeral are composed of an optional - prefix followed by digits only.

0
1234
-5678

The size and maximum/minimum values of and integer is implementation dependant, but should at least allow all the values of conventional 32 bits integers. In practice, integers are either 32, 48 or 64 bits wide, depending on compilation options.

Int::MAX    # The smallest integer representable
Int::MIN    # The largest integer representable
Int::BITS   # The number of usable bits

Floating point numbers

Floating point numbers are instances of the Float type and are either single or double precision depending on the implementation. Number literals are allowed in the form of a series of digits with a decimal point or in scientific notation of in hexadecimal notation.

3.14159
1.0
-12.34
0.0314159e02
0.0314159e+02
314.159e-02
0xcaffe2

Limits

Float::MIN              # The smallest finite possible value
Float::MIN_POSITIVE     # The smallest positive possible value
Float::MAX              # The largest finite possible value
Float::NAN              # Not a Number
Float::INF              # Infinity
Float::NEG_INF          # Negative infinity
Float::EPSILON          # The difference between 1.0 and the next value

Strings

Stings are instance of the Str type. A string is an array of byte, usually representing a string of character encoded in UTF-8. String literals are surrounded by double quotes:

"Hello, world!"

Escaping

Some characters need to be escaped with \

"\0"            # The NUL byte: 0.
"\""            # A double quote character.
"\\"            # A backslash.
"\$"            # A dollar sign.
"\a"            # Alarm beep.
"\b"            # Backspace.
"\e"            # ESC character.
"\f"            # Formfeed.
"\n"            # Newline.
"\r"            # Carriage return.
"\t"            # Tab.
"\v"            # Vertical tab.
"\x48"          # Unencoded byte     (2 hex digits)
"\u0041"        # Unicode code point (4 hex digits)
"\U0001F64A"    # Unicode code point (8 hex digits)

Interpolation

Not implemented yet.

Raw strings

Raw string literals are surrounded by 3 double quotes """ and do not process escaping or interpolation but leading/trailing whitespaces are ignored when the 3 double quotes are on a line by themselves.

# Those 2 strings are identical and do not contain any newlines.

"""Hello, world!"""

"""
Hello, world!
"""

Characters

Not implemented yet.

Charaters are instances of the Char type and allow to store any unicode code point. Charaters literals are not allowed you need to get a char from a string.

Arrays

Not implemented yet.

Arrays are ordered collections of values accessible by an integer index. Arrays are zero indexed (the index of the first element is 0).

[1, "hello", true]
[1, "hello", true,]     # trailing coma is allowed

var list : Array<Int> = [];
list.push(1);
list[0] == 5;

Maps

Not implemented yet.

["key_string" : 1, nil : "value_string", 0 : 1, ]

var map : Map<Any, Any> = [];
map["hello"] = 5;

User types

Not implemented yet.

struct S {
    name: Str,
    age: Int,   # trailing comma allowed
};

impl S {
    fn get_name(self) Str { self.name }
}