diff options
| -rw-r--r-- | 03-lexical-syntax.md | 25 | ||||
| -rw-r--r-- | 08-expressions.md | 85 | ||||
| -rw-r--r-- | 15-scala-syntax-summary.md | 36 |
3 files changed, 78 insertions, 68 deletions
diff --git a/03-lexical-syntax.md b/03-lexical-syntax.md index 7c2ec30181..7ea15ec9f4 100644 --- a/03-lexical-syntax.md +++ b/03-lexical-syntax.md @@ -408,8 +408,7 @@ members of type `Boolean`. ### Character Literals ``` -characterLiteral ::= ‘'’ printableChar ‘'’ - | ‘'’ charEscapeSeq ‘'’ +characterLiteral ::= ‘'’ (printableChar | charEscapeSeq) ‘'’ ``` A character literal is a single character enclosed in quotes. @@ -432,7 +431,7 @@ the octal escape `'\12'` ([see here](#escape-sequences)). ### String Literals ``` -stringLiteral ::= ‘\"’ {stringElement} ‘\"’ +stringLiteral ::= ‘"’ {stringElement} ‘"’ stringElement ::= printableCharNoDoubleQuote | charEscapeSeq ``` @@ -510,16 +509,16 @@ Because there is a predefined The following escape sequences are recognized in character and string literals. -| | | | | -|-------|----------|-----------------|------| -| `\b` | `\u0008` | backspace | BS | -| `\t` | `\u0009` | horizontal tab | HT | -| `\n` | `\u000a` | linefeed | LF | -| `\f` | `\u000c` | form feed | FF | -| `\r` | `\u000d` | carriage return | CR | -| `\"` | `\u0022` | double quote | " | -| `\'` | `\u0027` | single quote | ' | -| `\\` | `\u005c` | backslash | `\` | +| charEscapeSeq | unicode | name | char | +|---------------|----------|-----------------|--------| +| `‘\‘ ‘b‘` | `\u0008` | backspace | `BS` | +| `‘\‘ ‘t‘` | `\u0009` | horizontal tab | `HT` | +| `‘\‘ ‘n‘` | `\u000a` | linefeed | `LF` | +| `‘\‘ ‘f‘` | `\u000c` | form feed | `FF` | +| `‘\‘ ‘r‘` | `\u000d` | carriage return | `CR` | +| `‘\‘ ‘"‘` | `\u0022` | double quote | `"` | +| `‘\‘ ‘'‘` | `\u0027` | single quote | `'` | +| `‘\‘ ‘\‘` | `\u005c` | backslash | `\` | A character with Unicode between 0 and 255 may also be represented by diff --git a/08-expressions.md b/08-expressions.md index 6ab149cfc1..1eed192cc8 100644 --- a/08-expressions.md +++ b/08-expressions.md @@ -1,44 +1,44 @@ # Expressions ``` - Expr ::= (Bindings | id | `_') `=>' Expr - | Expr1 - Expr1 ::= `if' `(' Expr `)' {nl} Expr [[semi] `else' Expr] - | `while' `(' Expr `)' {nl} Expr - | `try' (`{' Block `}' | Expr) [`catch' `{' CaseClauses `}'] [`finally' Expr] - | `do' Expr [semi] `while' `(' Expr ')' - | `for' (`(' Enumerators `)' | `{' Enumerators `}') {nl} [`yield'] Expr - | `throw' Expr - | `return' [Expr] - | [SimpleExpr `.'] id `=' Expr - | SimpleExpr1 ArgumentExprs `=' Expr - | PostfixExpr - | PostfixExpr Ascription - | PostfixExpr `match' `{' CaseClauses `}' - PostfixExpr ::= InfixExpr [id [nl]] - InfixExpr ::= PrefixExpr - | InfixExpr id [nl] InfixExpr - PrefixExpr ::= [`-' | `+' | `~' | `!'] SimpleExpr - SimpleExpr ::= `new' (ClassTemplate | TemplateBody) - | BlockExpr - | SimpleExpr1 [`_'] - SimpleExpr1 ::= Literal - | Path - | `_' - | `(' [Exprs] `)' - | SimpleExpr `.' id s - | SimpleExpr TypeArgs - | SimpleExpr1 ArgumentExprs - | XmlExpr - Exprs ::= Expr {`,' Expr} - BlockExpr ::= `{' CaseClauses `}' - | `{' Block `}' - Block ::= {BlockStat semi} [ResultExpr] - ResultExpr ::= Expr1 - | (Bindings | ([`implicit'] id | `_') `:' CompoundType) `=>' Block - Ascription ::= `:' InfixType - | `:' Annotation {Annotation} - | `:' `_' `*' +Expr ::= (Bindings | id | `_') `=>' Expr + | Expr1 +Expr1 ::= `if' `(' Expr `)' {nl} Expr [[semi] `else' Expr] + | `while' `(' Expr `)' {nl} Expr + | `try' (`{' Block `}' | Expr) [`catch' `{' CaseClauses `}'] [`finally' Expr] + | `do' Expr [semi] `while' `(' Expr ')' + | `for' (`(' Enumerators `)' | `{' Enumerators `}') {nl} [`yield'] Expr + | `throw' Expr + | `return' [Expr] + | [SimpleExpr `.'] id `=' Expr + | SimpleExpr1 ArgumentExprs `=' Expr + | PostfixExpr + | PostfixExpr Ascription + | PostfixExpr `match' `{' CaseClauses `}' +PostfixExpr ::= InfixExpr [id [nl]] +InfixExpr ::= PrefixExpr + | InfixExpr id [nl] InfixExpr +PrefixExpr ::= [`-' | `+' | `~' | `!'] SimpleExpr +SimpleExpr ::= `new' (ClassTemplate | TemplateBody) + | BlockExpr + | SimpleExpr1 [`_'] +SimpleExpr1 ::= Literal + | Path + | `_' + | `(' [Exprs] `)' + | SimpleExpr `.' id s + | SimpleExpr TypeArgs + | SimpleExpr1 ArgumentExprs + | XmlExpr +Exprs ::= Expr {`,' Expr} +BlockExpr ::= ‘{’ CaseClauses ‘}’ + | ‘{’ Block ‘}’ +Block ::= BlockStat {semi BlockStat} [ResultExpr] +ResultExpr ::= Expr1 + | (Bindings | ([`implicit'] id | `_') `:' CompoundType) `=>' Block +Ascription ::= `:' InfixType + | `:' Annotation {Annotation} + | `:' `_' `*' ``` Expressions are composed of operators and operands. Expression forms are @@ -558,8 +558,9 @@ where `anon\$X` is some freshly created name. ## Blocks ``` -BlockExpr ::= `{' Block `}' -Block ::= {BlockStat semi} [ResultExpr] +BlockExpr ::= ‘{’ CaseClauses ‘}’ + | ‘{’ Block ‘}’ +Block ::= BlockStat {semi BlockStat} [ResultExpr] ``` A block expression `{$s_1$; $\ldots$; $s_n$; $e\,$}` is @@ -1319,10 +1320,10 @@ include at least the expressions of the following forms: ``` BlockStat ::= Import - | {Annotation} [`implicit'] Def + | {Annotation} [‘implicit’ | ‘lazy’] Def | {Annotation} {LocalModifier} TmplDef | Expr1 - | + | TemplateStat ::= Import | {Annotation} {Modifier} Def | {Annotation} {Modifier} Dcl diff --git a/15-scala-syntax-summary.md b/15-scala-syntax-summary.md index 7d6fc10d3e..d4d5166312 100644 --- a/15-scala-syntax-summary.md +++ b/15-scala-syntax-summary.md @@ -1,17 +1,28 @@ # Scala Syntax Summary -<!-- TODO: introduce SeqPattern syntax --> +The following descriptions of Scala tokens uses literal characters `‘c’` when referring to the ASCII fragment `\u0000` – `\u007F`. -The lexical syntax of Scala is given by the following grammar in EBNF -form. +_Unicode escapes_ are used to represent the Unicode character with the given hexadecimal code: + +``` +UnicodeEscape ::= ‘\‘ ‘u‘ {‘u‘} hexDigit hexDigit hexDigit hexDigit +hexDigit ::= ‘0’ | … | ‘9’ | ‘A’ | … | ‘F’ | ‘a’ | … | ‘f’ +``` + +The lexical syntax of Scala is given by the following grammar in EBNF form: ``` -upper ::= ‘A’ | … | ‘Z’ | ‘\$’ | ‘_’ // and Unicode category Lu +whiteSpace ::= ‘\u0020’ | ‘\u0009’ | ‘\u000D’ | ‘\u000A’ +upper ::= ‘A’ | … | ‘Z’ | ‘$’ | ‘_’ // and Unicode category Lu lower ::= ‘a’ | … | ‘z’ // and Unicode category Ll letter ::= upper | lower // and Unicode categories Lo, Lt, Nl digit ::= ‘0’ | … | ‘9’ -opchar ::= // “all other characters in \u0020-\u007F and Unicode - // categories Sm, So except parentheses ([{}]) and periods” +paren ::= ‘(’ | ‘)’ | ‘[’ | ‘]’ | ‘{’ | ‘}’ +delim ::= ‘`’ | ‘'’ | ‘"’ | ‘.’ | ‘;’ | ‘,’ +opchar ::= // printableChar not matched by (whiteSpace | upper | lower | + // letter | digit | paren | delim | opchar | Unicode_Sm | Unicode_So) +printableChar ::= // all characters in [\u0020, \u007F] inclusive +charEscapeSeq ::= ‘\‘ (‘b‘ | ‘t‘ | ‘n‘ | ‘f‘ | ‘r‘ | ‘"‘ | ‘'‘ | ‘\‘) op ::= opchar {opchar} varid ::= lower idrest @@ -19,7 +30,7 @@ plainid ::= upper idrest | varid | op id ::= plainid - | ‘\`’ stringLiteral ‘\`’ + | ‘`’ stringLiteral ‘`’ idrest ::= {letter | digit} [‘_’ op] integerLiteral ::= (decimalNumeral | hexNumeral) [‘L’ | ‘l’] @@ -38,18 +49,17 @@ floatType ::= ‘F’ | ‘f’ | ‘D’ | ‘d’ booleanLiteral ::= ‘true’ | ‘false’ -characterLiteral ::= ‘\'‘ printableChar ‘\'’ - | ‘\’ charEscapeSeq ‘\'’ +characterLiteral ::= ‘'’ (printableChar | charEscapeSeq) ‘'’ stringLiteral ::= ‘"’ {stringElement} ‘"’ | ‘"""’ multiLineChars ‘"""’ -stringElement ::= printableCharNoDoubleQuote +stringElement ::= (printableChar except ‘"’) | charEscapeSeq multiLineChars ::= {[‘"’] [‘"’] charNoDoubleQuote} {‘"’} symbolLiteral ::= ‘'’ plainid -comment ::= ‘/*’ “any sequence of characters” ‘*/’ +comment ::= ‘/*’ “any sequence of characters; nested comments are allowed” ‘*/’ | ‘//’ “any sequence of characters up to end of line” nl ::= $\mathit{“new line character”}$ @@ -141,7 +151,7 @@ grammar. | [nl] BlockExpr BlockExpr ::= ‘{’ CaseClauses ‘}’ | ‘{’ Block ‘}’ - Block ::= {BlockStat semi} [ResultExpr] + Block ::= BlockStat {semi BlockStat} [ResultExpr] BlockStat ::= Import | {Annotation} [‘implicit’ | ‘lazy’] Def | {Annotation} {LocalModifier} TmplDef @@ -210,7 +220,6 @@ grammar. Annotation ::= ‘@’ SimpleType {ArgumentExprs} ConstrAnnotation ::= ‘@’ SimpleType ArgumentExprs - NameValuePair ::= ‘val’ id ‘=’ PrefixExpr TemplateBody ::= [nl] ‘{’ [SelfType] TemplateStat {semi TemplateStat} ‘}’ TemplateStat ::= Import @@ -287,6 +296,7 @@ grammar. ``` <!-- TODO add: +SeqPattern ::= ... SimplePattern ::= StableId [TypePatArgs] [‘(’ [SeqPatterns] ‘)’] TypePatArgs ::= ‘[’ TypePatArg {‘,’ TypePatArg} ‘]’ |