diff options
Diffstat (limited to 'spec')
| -rw-r--r-- | spec/syntax.abnf | 96 | ||||
| -rw-r--r-- | spec/syntax.md | 117 | ||||
| -rw-r--r-- | spec/syntax.peg | 63 | ||||
| -rw-r--r-- | spec/syntax.zbnf | 59 |
4 files changed, 0 insertions, 335 deletions
diff --git a/spec/syntax.abnf b/spec/syntax.abnf deleted file mode 100644 index 132deeb..0000000 --- a/spec/syntax.abnf +++ /dev/null @@ -1,96 +0,0 @@ -;This file follows strict ABNF rules and can be used with abnfgen. - - -File = [Unit] *( Blank Unit ) *Blank [Trail] - - -Unit = *Blank Datum - -Blank = HTAB / LF / %x0b / %x0c / CR / SP / Comment - -Trail = SkipLine / SkipUnit - - -Datum = BareString - / DottedString - / CladDatum - / HashExpr - / HashDotExpr - / QuoteExpr - / JoinExpr - -Comment = SkipLine LF / SkipUnit Blank - -SkipLine = ';' [ SkipLStart *AnyButLF ] - -SkipLStart = %x00-09 / %x0b-7d / %x7f-ff - ; any but LF or '~' - -AnyButLF = %x00-09 / %x0b-ff - -SkipUnit = ';' '~' Unit - - -BareString = BareChar *( BareChar / Numeric ) - -DottedString = ( '.' / Numeric ) *( '.' / Numeric / BareChar ) - -CladDatum = '|' *( PipeStrChar / '\' StringEsc ) '|' - / '"' *( QuotStrChar / '\' StringEsc ) '"' - / '(' List ')' / '[' List ']' / '{' List '}' - -HashExpr = LabelExpr / RuneExpr / HashDatum - -HashDotExpr = RuneDotExpr / HashDotDatum - -QuoteExpr = "'" Datum / '`' Datum / ',' Datum - -JoinExpr = Datum LeftCladDatum - / Datum ':' Datum - / DotlessDatum '.' Datum - -LeftCladDatum = CladDatum / HashExpr / QuoteExpr - -DotlessDatum = BareString / CladDatum / RuneExpr / HashDatum - - -BareChar = '!' / '$' / '%' / '*' / '/' / '<' / '=' / '>' - / '?' / '@' / '^' / '_' / '~' / ALPHA - -Numeric = '+' / '-' / DIGIT - -PipeStrChar = %x00-5b / %x5d-7b / %x7d-ff - ; any but '|' or '\' - -QuotStrChar = %x00-21 / %x23-5b / %x5d-ff - ; any but '"' or '\' - -List = [Unit] *( Blank Unit ) *Blank [Tail] [SkipUnit] - -Tail = '&' Unit *Blank - -LabelExpr = '#' '%' Label ( '%' / '=' Datum ) - -RuneExpr = '#' Rune [ '\' BareString / CladDatum ] - -RuneDotExpr = '#' Rune '\' DottedString - -HashDatum = '#' '\' BareString / CladDatum - -HashDotDatum = '#' '\' DottedString - - -; Unicode escapes must not represent surrogate code points. -; This is difficult to express in ABNF. But we do at least -; disallow code points greater than \u10FFFF which are also -; invalid, since U+10FFFF is the highest allowed. -StringEsc = '\' / '|' / '"' / *( HTAB / SP ) LF *( HTAB / SP ) - / 'a' / 'b' / 't' / 'n' / 'v' / 'f' / 'r' / 'e' - / 'x' 1*( 2HEXDIG ) ';' - / 'u' ['0'] 1*5HEXDIG ';' - / 'u' '1' '0' 4HEXDIG ';' - - -Rune = ALPHA *5( ALPHA / DIGIT ) - -Label = 1*12( HEXDIG ) diff --git a/spec/syntax.md b/spec/syntax.md deleted file mode 100644 index d1a17ad..0000000 --- a/spec/syntax.md +++ /dev/null @@ -1,117 +0,0 @@ -# Zisp S-Expression Syntax - -We use a BNF-like grammar notation with the following rules: - -* Concatenation of expressions is implicit: `foo bar` means `foo` - followed by `bar`. - -* The suffixes `?`, `*`, and `+` have the same meaning as in regular - expressions, although `[foo]` is used in place of `(foo)?`. - -* The syntax is defined in terms of bytes, not characters. Terminals - `'c'` and `"c"` refer to the ASCII value of the given character `c`. - Numbers are in decimal and refer to a byte with the given value. - -* The prefix `~` means NOT. It only applies to rules that match one - byte, and negates them. For example, `~( 'a' | 'b' )` matches any - byte other than 97 and 98. - -* Ranges of terminal values are expressed as `x...y` (inclusive). - -* ABNF "core rules" like `ALPHA` and `HEXDIG` are supported. - -* There is no ambiguity, or look-ahead / backtracking beyond one byte. - Rules match left to right, depth-first, and greedy. As soon as the - input matches the first terminal of a rule (explicit or implied by - recursively descending into the first non-terminal), it must match - that rule to the end, or it is considered a syntax error. - -The last rule means that the notation is simple to translate to code. -It ostensibly makes the notation equivalent to PEG in expression. - -The parser consumes one `Unit` from an input stream every time it's -called; it returns the `Datum` therein, or EOF. The final optional -`Blank` represents the fact that the parser will consume one more -blank at the end if it finds one; this is because `Datum` is not -self-closing so the parser has to check if it goes on. - -The following limits are not represented in the grammar: - -* A `UnicodeSV` is the hexadecimal representation of a Unicode scalar - value; it must represent a value in the range 0 to D7FF, or E000 to - 10FFFF, inclusive. Any other value signals an error. Valid values - are converted into a UTF-8 byte sequence encoding the value. - -* A `Rune` longer than 6 bytes is grammatical, but signals an error. - This is important because runes are not self-terminating; defining - their grammar as ending after a maximum of 6 bytes would allow - another datum beginning with an alphabetic character to follow a - rune immediately without any visual delineation, which would be - terribly confusing for a human reader. Consider: `#foo123bar`. - This would parse as a concatenation of `#foo123` and `bar`. - -* A `Label` is the hexadecimal representation of a 48-bit integer, - meaning it allows for a maximum of 12 hexadecimal digits. Longer - values are grammatical, but signal an out-of-range error. - -``` -Unit : Blank* [ Datum [Blank] ] - - -Blank : 9...13 | SP | Comment - -Datum : OneDatum ( [JoinChar] OneDatum )* - -JoinChar : '.' | ':' - - -Comment : ';' ( SkipUnit | SkipLine ) - -SkipUnit : '~' Unit - -SkipLine : ( ~LF )* [LF] - - -OneDatum : BareString | CladDatum - - -BareString : ( '.' | '+' | '-' | DIGIT ) ( BareChar | '.' )* - | BareChar+ - -CladDatum : PipeStr | QuoteStr | HashExpr | QuoteExpr | List - -PipeStr : '|' ( PipeStrChar | '\' StringEsc )* '|' -QuoteStr : '"' ( QuotStrChar | '\' StringEsc )* '"' -HashExpr : '#' ( RuneExpr | LabelExpr | HashDatum ) -QuoteExpr : "'" Datum | '`' Datum | ',' Datum -List : ParenList | SquareList | BraceList - -BareChar : ALPHA | DIGIT - | '!' | '$' | '%' | '*' | '+' - | '-' | '/' | '<' | '=' | '>' - | '?' | '@' | '^' | '_' | '~' - -PipeStrChar : ~( '|' | '\' ) -QuotStrChar : ~( '"' | '\' ) - -StringEsc : '\' | '|' | '"' | ( HTAB | SP )* LF ( HTAB | SP )* - | 'a' | 'b' | 't' | 'n' | 'v' | 'f' | 'r' | 'e' - | 'x' HexByte+ ';' - | 'u' UnicodeSV ';' - -HexByte : HEXDIG HEXDIG -UnicodeSV : HEXDIG+ - -RuneExpr : Rune [ '\' BareString | CladDatum ] -LabelExpr : '%' Label ( '%' | '=' Datum ) -HashDatum : '\' BareString | CladDatum - -Rune : ALPHA ( ALPHA | DIGIT )* -Label : HEXDIG+ - -ParenList : '(' ListBody ')' -SquareList : '[' ListBody ']' -BraceList : '{' ListBody '}' - -ListBody : Unit* [ Blank* '&' Unit ] Blank* -``` diff --git a/spec/syntax.peg b/spec/syntax.peg deleted file mode 100644 index 97b9632..0000000 --- a/spec/syntax.peg +++ /dev/null @@ -1,63 +0,0 @@ -Unit <- Blank* ( Datum Blank? )? - - -Blank <- ' ' / '\t' / '\n' / Comment - -Datum <- OneDatum ( JoinChar? OneDatum )* - -JoinChar <- '.' / ':' - - -Comment <- ';' ( SkipUnit / SkipLine ) - -SkipUnit <- '~' Unit - -SkipLine <- (!'\n' .)* '\n'? - - -OneDatum <- BareString / CladDatum - - -BareString <- ( '.' / '+' / '-' / DIGIT ) ( BareChar / '.' )* - / BareChar+ - -CladDatum <- PipeStr / QuoteStr / HashExpr / QuoteExpr / List - -PipeStr <- '|' ( PipeStrChar / '\' StringEsc )* '|' -QuoteStr <- '"' ( QuotStrChar / '\' StringEsc )* '"' -HashExpr <- '#' ( RuneExpr / LabelExpr / HashDatum ) -QuoteExpr <- "'" Datum / '`' Datum / ',' Datum -List <- ParenList / SquareList / BraceList - -BareChar <- ALPHA / DIGIT - / '!' / '$' / '%' / '*' / '+' - / '-' / '/' / '<' / '=' / '>' - / '?' / '@' / '^' / '_' / '~' - -PipeStrChar <- (![|\\] .) -QuotStrChar <- (!["\\] .) - -StringEsc <- '\' / '|' / '"' / ( HTAB / SP )* LF ( HTAB / SP )* - / 'a' / 'b' / 't' / 'n' / 'v' / 'f' / 'r' / 'e' - / 'x' HexByte+ ';' - / 'u' UnicodeSV ';' - -HexByte <- HEXDIG HEXDIG -UnicodeSV <- HEXDIG+ - -RuneExpr <- Rune [ '\' BareString / CladDatum ] -LabelExpr <- '%' Label ( '%' / '=' Datum ) -HashDatum <- '\' BareString / CladDatum - -Rune <- ALPHA ( ALPHA / DIGIT )* -Label <- HEXDIG+ - -ParenList <- '(' ListBody ')' -SquareList <- '[' ListBody ']' -BraceList <- '{' ListBody '}' - -ListBody <- Unit* [ Blank* '&' Unit ] Blank* - -DIGIT <- [0-9] -ALPHA <- [a-zA-Z] -HEXDIG <- [0-9a-fA-F] diff --git a/spec/syntax.zbnf b/spec/syntax.zbnf deleted file mode 100644 index b87efb5..0000000 --- a/spec/syntax.zbnf +++ /dev/null @@ -1,59 +0,0 @@ -Unit : Blank* [ Datum [Blank] ] - - -Blank : 9...13 | SP | Comment - -Datum : OneDatum ( [JoinChar] OneDatum )* - -JoinChar : '.' | ':' - - -Comment : ';' ( SkipUnit | SkipLine ) - -SkipUnit : '~' Unit - -SkipLine : ( ~LF )* [LF] - - -OneDatum : BareString | CladDatum - - -BareString : ( '.' | '+' | '-' | DIGIT ) ( BareChar | '.' )* - | BareChar+ - -CladDatum : PipeStr | QuoteStr | HashExpr | QuoteExpr | List - -PipeStr : '|' ( PipeStrChar | '\' StringEsc )* '|' -QuoteStr : '"' ( QuotStrChar | '\' StringEsc )* '"' -HashExpr : '#' ( RuneExpr | LabelExpr | HashDatum ) -QuoteExpr : "'" Datum | '`' Datum | ',' Datum -List : ParenList | SquareList | BraceList - -BareChar : ALPHA | DIGIT - | '!' | '$' | '%' | '*' | '+' - | '-' | '/' | '<' | '=' | '>' - | '?' | '@' | '^' | '_' | '~' - -PipeStrChar : ~( '|' | '\' ) -QuotStrChar : ~( '"' | '\' ) - -StringEsc : '\' | '|' | '"' | ( HTAB | SP )* LF ( HTAB | SP )* - | 'a' | 'b' | 't' | 'n' | 'v' | 'f' | 'r' | 'e' - | 'x' HexByte+ ';' - | 'u' UnicodeSV ';' - -HexByte : HEXDIG HEXDIG -UnicodeSV : HEXDIG+ - -RuneExpr : Rune [ '\' BareString | CladDatum ] -LabelExpr : '%' Label ( '%' | '=' Datum ) -HashDatum : '\' BareString | CladDatum - -Rune : ALPHA ( ALPHA | DIGIT )* -Label : HEXDIG+ - -ParenList : '(' ListBody ')' -SquareList : '[' ListBody ']' -BraceList : '{' ListBody '}' - -ListBody : Unit* [ Blank* '&' Unit ] Blank* |