@ -21,8 +21,7 @@ will autodetect this case and do the right thing.
In other cases, *(added 0.50)* you can get multi-line statements by ending the
line with a `\` . Apart from line ending whitespace has no syntactic meaning.
Variables
--
## Variables
Variables in Meson work just like in other high level programming
languages. A variable can contain a value of any type, such as an
@ -47,8 +46,7 @@ var2 += [4]
# var1 is still [1, 2, 3]
```
Numbers
--
## Numbers
Meson supports only integer numbers. They are declared simply by
writing them out. Basic arithmetic operations are supported.
@ -86,8 +84,7 @@ int_var = 42
string_var = int_var.to_string()
```
Booleans
--
## Booleans
A boolean is either `true` or `false` .
@ -95,8 +92,7 @@ A boolean is either `true` or `false`.
truth = true
```
Strings
--
## Strings
Strings in Meson are declared with single quotes. To enter a literal
single quote do it like this:
@ -127,7 +123,7 @@ As in python and C, up to three octal digits are accepted in `\ooo`.
Unrecognized escape sequences are left in the string unchanged, i.e., the
backslash is left in the string.
#### String concatenation
### String concatenation
Strings can be concatenated to form a new string using the `+` symbol.
@ -137,7 +133,7 @@ str2 = 'xyz'
combined = str1 + '_' + str2 # combined is now abc_xyz
```
#### String path building
### String path building
*(Added 0.49)*
@ -155,7 +151,7 @@ joined = 'C:\\foo\\bar' / 'D:\\builddir' # => D:/builddir
Note that this is equivalent to using [`join_paths()` ](Reference-manual.md#join_paths ),
which was obsoleted by this operator.
#### Strings running over multiple lines
### Strings running over multiple lines
Strings running over multiple lines can be declared with three single
quotes, like this:
@ -171,7 +167,7 @@ These are raw strings that do not support the escape sequences listed
above. These strings can also be combined with the string formatting
functionality described below.
#### String formatting
### String formatting
Strings can be built using the string formatting functionality.
@ -184,12 +180,12 @@ res = template.format('text', 1, true)
As can be seen, the formatting works by replacing placeholders of type
`@number@` with the corresponding argument.
#### String methods
### String methods
Strings also support a number of other methods that return transformed
copies.
**.strip()**
#### .strip()
```meson
# Similar to the Python str.strip(). Removes leading/ending spaces and newlines
@ -198,7 +194,7 @@ stripped_define = define.strip()
# 'stripped_define' now has the value '-Dsomedefine'
```
**.to_upper()**, ** .to_lower()**
#### .to_upper(), .to_lower()
```meson
target = 'x86_FreeBSD'
@ -206,7 +202,7 @@ upper = target.to_upper() # t now has the value 'X86_FREEBSD'
lower = target.to_lower() # t now has the value 'x86_freebsd'
```
**.to_int()**
#### .to_int()
```meson
version = '1'
@ -214,7 +210,7 @@ version = '1'
ver_int = version.to_int()
```
**.contains()**, ** .startswith()**, ** .endswith()**
#### .contains(), .startswith(), .endswith()
```meson
target = 'x86_FreeBSD'
@ -224,7 +220,7 @@ is_x86 = target.startswith('x86') # boolean value 'true'
is_bsd = target.to_lower().endswith('bsd') # boolean value 'true'
```
**.split()**, ** .join()**
#### .split(), .join()
```meson
# Similar to the Python str.split()
@ -265,7 +261,7 @@ api_version = '@0@.@1@'.format(version_array[0], version_array[1])
# api_version now (again) has the value '0.2'
```
**.underscorify()**
#### .underscorify()
```meson
name = 'Meson Docs.txt#Reference-manual'
@ -275,7 +271,7 @@ underscored = name.underscorify()
# underscored now has the value 'Meson_Docs_txt_Reference_manual'
```
**.version_compare()**
#### .version_compare()
```meson
version = '1.2.3'
@ -285,8 +281,7 @@ is_new = version.version_compare('>=2.0')
# Supports the following operators: '>', '< ', '>=', '< =', '!=', '==', '='
```
Arrays
--
## Arrays
Arrays are delimited by brackets. An array can contain an arbitrary number of objects of any type.
@ -321,6 +316,7 @@ assign it to `my_array` instead of modifying the original since all
objects in Meson are immutable.
Since 0.49.0, you can check if an array contains an element like this:
```meson
my_array = [1, 2]
if 1 in my_array
@ -331,7 +327,7 @@ if 1 not in my_array
endif
```
#### Array methods
### Array methods
The following methods are defined for all arrays:
@ -339,8 +335,7 @@ The following methods are defined for all arrays:
- `contains` , returns `true` if the array contains the object given as argument, `false` otherwise
- `get` , returns the object at the given index, negative indices count from the back of the array, indexing out of bounds is a fatal error. Provided for backwards-compatibility, it is identical to array indexing.
Dictionaries
--
## Dictionaries
Dictionaries are delimited by curly braces. A dictionary can contain an
arbitrary number of key value pairs. Keys are required to be strings, values can
@ -365,6 +360,7 @@ Visit the [Reference Manual](Reference-manual.md#dictionary-object) to read
about the methods exposed by dictionaries.
Since 0.49.0, you can check if a dictionary contains a key like this:
```meson
my_dict = {'foo': 42, 'bar': 43}
if 'foo' in my_dict
@ -380,14 +376,14 @@ endif
*Since 0.53.0* Keys can be any expression evaluating to a string value, not limited
to string literals any more.
```meson
d = {'a' + 'b' : 42}
k = 'cd'
d += {k : 43}
```
Function calls
--
## Function calls
Meson provides a set of usable functions. The most common use case is
creating build objects.
@ -432,8 +428,7 @@ executable('progname', 'prog.c',
Attempting to do this causes Meson to immediately exit with an error.
Method calls
--
## Method calls
Objects can have methods, which are called with the dot operator. The
exact methods it provides depends on the object.
@ -443,8 +438,7 @@ myobj = some_function()
myobj.do_something('now')
```
If statements
--
## If statements
If statements work just like in other languages.
@ -465,8 +459,7 @@ if opt != 'foo'
endif
```
Logical operations
--
## Logical operations
Meson has the standard range of logical operations which can be used in
`if` statements.
@ -556,8 +549,7 @@ endforeach
# result is ['a', 'b']
```
Comments
--
## Comments
A comment starts with the `#` character and extends until the end of the line.
@ -566,8 +558,7 @@ some_function() # This is a comment
some_other_function()
```
Ternary operator
--
## Ternary operator
The ternary operator works just like in other languages.
@ -579,8 +570,7 @@ The only exception is that nested ternary operators are forbidden to
improve legibility. If your branching needs are more complex than this
you need to write an `if/else` construct.
Includes
--
## Includes
Most source trees have multiple subdirectories to process. These can
be handled by Meson's `subdir` command. It changes to the given
@ -595,8 +585,7 @@ test_data_dir = 'data'
subdir('tests')
```
User-defined functions and methods
--
## User-defined functions and methods
Meson does not currently support user-defined functions or
methods. The addition of user-defined functions would make Meson
@ -608,8 +597,7 @@ because of this limitation you find yourself copying and pasting code
a lot you may be able to use a [`foreach` loop
instead](#foreach-statements).
Stability Promises
--
## Stability Promises
Meson is very actively developed and continuously improved. There is a
possibility that future enhancements to the Meson build system will require
@ -618,8 +606,7 @@ keywords, changing the meaning of existing keywords or additions around the
basic building blocks like statements and fundamental types. It is planned
to stabilize the syntax with the 1.0 release.
Grammar
--
## Grammar
This is the full Meson grammar, as it is used to parse Meson build definition files:
@ -641,7 +628,7 @@ equality_expression: relational_expression | (equality_expression equality_opera
equality_operator: "==" | "!="
expression: assignment_expression
expression_list: expression ("," expression)*
expression_statememt: expression
expression_statememt: expression
function_expression: id_expression "(" [argument_list] ")"
hex_literal: "0x" HEX_NUMBER
HEX_NUMBER: /[a-fA-F0-9]+/
Michael Hirsch, Ph.D
4 years ago
committed by
Jussi Pakkanen