78 lines
2.5 KiB
Plaintext
78 lines
2.5 KiB
Plaintext
# This is a file defining the BP grammar using BP syntax
|
|
|
|
Grammar: __ *(Def [__`;])%__ __ ($$ / @!=(..$$%\n => "Could not parse this code"))
|
|
Def: @name=id __ `: __ (
|
|
@definition=extended-pat
|
|
/ $$ @!=(''=>"No definition for rule")
|
|
/ @!=(..>(`;/id_`:/$)%\n => "Invalid definition: @0"))
|
|
|
|
# This is used for command line arguments:
|
|
String-pattern: ..$$ % (\n / Nodent / Escape / `\ pat [`;])
|
|
|
|
pat: simple-pat !(__("!="/"==")) / suffixed-pat
|
|
simple-pat: Upto-and / Dot / String / Chars / Nodent / Escape-range
|
|
/ Escape / Repeat / Optional / No / After / Before / Capture
|
|
/ Ref / parens
|
|
|
|
suffixed-pat: (
|
|
Eq-pat
|
|
/ Not-eq-pat
|
|
)
|
|
|
|
Eq-pat: @first=pat__"=="__@second=pat
|
|
Not-eq-pat: @first=pat__"!="__@second=pat
|
|
|
|
Dot: `. !`.
|
|
String: (
|
|
`" @s=*(Escape / !`".) (`" / @!=(''=> "Expected closing quote here"))
|
|
/ `' @s=*(Escape / !`'.) (`' / @!=(''=> "Expected closing quote here"))
|
|
)
|
|
Chars: `` @+(Char-range/Char) % `,
|
|
Char-range: @low=. `- (@high=. / @!=(''=> "Expected a second character to form a character range"))
|
|
Char: (@s=. / @!=(''=> "Expected a character following the '`'"))
|
|
Escape-range: `\ @low=escape-sequence `- @high=escape-sequence
|
|
Escape: `\ (@s=escape-sequence
|
|
/ $ @!=(''=>"Backslashes are used for escape sequences, not splitting lines")
|
|
/ @!=(. *(Abc/`0-9) => "Invalid escape sequence: '@0'")
|
|
)
|
|
escape-sequence: (
|
|
`n,t,r,e,b,a,v
|
|
/ 1-3 `0-7
|
|
/ `x 2 `0-9,a-f,A-F
|
|
)
|
|
No: `! (__@pat / @!=(''=>"Expected a pattern after the exclamation mark"))
|
|
Nodent: `\ `N
|
|
Upto-and: ".." [__@first=simple-pat] [__`%__@second=simple-pat]
|
|
Repeat: (
|
|
@min=(''=>'0') `* @max=''
|
|
/ @min=int __ `- __ @max=int
|
|
/ @min=(int / ''=>'1') __ `+ @max=''
|
|
/ @min=@max=int
|
|
) __ @repeat-pat=pat [__`%__@sep=pat]
|
|
Optional: `[ __ extended-pat (__`] / @!=(''=> "Expected closing square bracket here"))
|
|
After: `< __ pat
|
|
Before: `> __ pat
|
|
Capture: `@ [__ @capture-name=(id/`!) __ !"=>" `=] __ (@capture=pat / @!=(''=> "Expected pattern to capture"))
|
|
Replace: (
|
|
@replace-pat=(Replace / Chain / pat) __ "=>" (__ @replacement=String / @!=(''=> "Expected replacement string"))
|
|
)
|
|
Ref: @name=id !(__`:)
|
|
|
|
parens: `( __ extended-pat (__ `) / @!=(''=> "Expected closing parenthesis here"))
|
|
|
|
Chain: 2+@(pat !(__"=>") / Replace)%__
|
|
Otherwise: 2+@(Replace / Chain / pat)%(__`/__)
|
|
extended-pat: Otherwise / Replace / Chain / pat
|
|
|
|
# Special-symbol rules:
|
|
_: *(` / \t)
|
|
__: *(` / \t / \r / \n / comment)
|
|
$$: !(./\n)
|
|
$: !.
|
|
^^: !<(./\n)
|
|
^: !<.
|
|
|
|
id: "^^" / "^" / "__" / "_" / "$$" / "$" / "|" / `a-z,A-Z *`a-z,A-Z,0-9,-
|
|
|
|
comment: `# .. $
|