Booleans¶

Booleans are either `true` or `false`.

OPERATORS

Integers¶

You can specify an integer literal using decimal, hexadecimal, octal, and binary.

int_1 = 1
int_42 = 42
int_255 = 0xFF
int_493 = 0o755
int_1365 = 0b10101010101

All common arithmetic operations are implemented for integers: addition, subtraction, division, multiplication, and modulo.

OPERATORS

Strings¶

Strings in Meson are declared with single quotes. `` is the escape character.

The full list of escape sequences is:

Multi-line strings are surrounded by 3 consecutive quotes. These are raw strings that do not support the escape sequences listed above.

Format strings are expressed by a placing leading `f` before the first opening quote. Inside of a format string, sequences of the form `@[a-z_]+@` will be substituted with the value of the matching variable.

name = 'Alice'
# prints "Hello Alice"
message(f'Hello @name@')

OPERATORS

Arrays¶

Arrays are delimited by brackets. An array can contain an arbitrary number of objects of any type.

OPERATORS

Dictionaries¶

Dictionaries are delimited by curly braces. A dictionary can contain an arbitrary number of key: value pairs. Keys are required to be strings, but values can be objects of any type. Dictionaries are immutable and do not have a guaranteed order.

OPERATORS

Comments¶

A comment starts with the `#` character and extends until the end of the line.

Variables¶

A variable can contain a value of any type, and does not need to be predeclared.

var1 = 'hello'
var2 = 102

One important difference in how variables work in the dsl is that all objects are immutable. When you see an operation which appears like a mutation, actually a new object is created and assigned to the name.

var1 = [1, 2, 3]
var2 = var1
var2 += [4]
# var2 is now [1, 2, 3, 4]
# var1 is still [1, 2, 3]

Function and method calls¶

Builtin functions are called by their name followed by parenthesis containing optional, comma-separated arguments. Arguments are either positional or keyword. Keyword arguments are expressed using the keyword without quotes, followed by a colon.

foo()
foo('bar')
foo('bar', baz: true)

Method calls are expressed by a `.` followed by the same function call syntax as above.

foo.bar()
foo.bar('baz', qux: false)

For a complete list of functions and methods, please see `meson-reference(3)`.

If statements¶

Start an if statement with the `if` keyword followed by a boolean expression. Further conditions can be expressed using the `elif` keyword followed by a boolean expression. The `else` keyword can be used to handle the case when no conditions are matched. An if statement is terminated with the `endif` keyword.

if conditon1
elif condition2
else condition3
endif

Foreach statements¶

To loop over values in an iterable, use the `foreach` keyword followed by a comma separated list of names to assign the values of the iterable to, a colon, and an iterable expression. Only arrays and dictionaries are iterable. A foreach statement is terminated with the `endforeach` keyword.

Arrays have one value to assign to.

foreach value : array
	foo(value)
endforeach

Dictionaries have one two values to assign to.

foreach key, value : dictionary
	foo(key)
	bar(value)
endforeach

Inside a `foreach` block you may use the `break` and `continue` keywords. `break` exits the loop immediately. `continue` skips the rest of the current iteration.