1ac5b4ea42
Recipes may now have a final variadic parameter:
```make
foo bar+:
@echo {{bar}}
```
Variadic parameters accept one or more arguments, and expand to a string containing those arguments separated by spaces:
```sh
$ just foo a b c d e
a b c d e
```
I elected to accept one or more arguments instead of zero or more arguments since unexpectedly empty arguments can sometimes be dangerous.
```make
clean dir:
rm -rf {{dir}}/bin
```
If `dir` is empty in the above recipe, you'll delete `/bin`, which is probably not what was intended.
1.6 KiB
1.6 KiB
justfile grammar
Justfiles are processed by a mildly context-sensitive tokenizer and a recursive descent parser. The grammar is mostly LL(1), although an extra token of lookahead is used to distinguish between export assignments and recipes with parameters.
tokens
BACKTICK = `[^`\n\r]*`
COLON = :
COMMENT = #([^!].*)?$
NEWLINE = \n|\r\n
EQUALS = =
INTERPOLATION_START = {{
INTERPOLATION_END = }}
NAME = [a-zA-Z_-][a-zA-Z0-9_-]*
PLUS = +
RAW_STRING = '[^'\r\n]*'
STRING = "[^"]*" # also processes \n \r \t \" \\ escapes
INDENT = emitted when indentation increases
DEDENT = emitted when indentation decreases
LINE = emitted before a recipe line
TEXT = recipe text, only matches in a recipe body
grammar
justfile : item* EOF
item : recipe
| assignment
| export
| eol
eol : NEWLINE
| COMMENT NEWLINE
assignment : NAME '=' expression eol
export : 'export' assignment
expression : STRING
| RAW_STRING
| NAME
| BACKTICK
| expression '+' expression
recipe : '@'? NAME parameter* ('+' parameter)? ':' dependencies? body?
parameter : NAME
| NAME '=' STRING
| NAME '=' RAW_STRING
dependencies : NAME+
body : INDENT line+ DEDENT
line : LINE (TEXT | interpolation)+ NEWLINE
| NEWLINE
interpolation : '{{' expression '}}'