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| author | Martin Odersky <odersky@gmail.com> | 2003-09-15 20:20:14 +0000 |
|---|---|---|
| committer | Martin Odersky <odersky@gmail.com> | 2003-09-15 20:20:14 +0000 |
| commit | dc6ec50a08dcd17aa65a73701abd6963b78a00bc (patch) | |
| tree | 00e884ffbe6776f51be59bb249012190ab757a08 /doc | |
| parent | 1b77651f90d9b4132e419409295f0d3c6153cf41 (diff) | |
| download | scala-dc6ec50a08dcd17aa65a73701abd6963b78a00bc.tar.gz scala-dc6ec50a08dcd17aa65a73701abd6963b78a00bc.tar.bz2 scala-dc6ec50a08dcd17aa65a73701abd6963b78a00bc.zip | |
*** empty log message ***
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/reference/ScalaReference.tex | 29 |
1 files changed, 13 insertions, 16 deletions
diff --git a/doc/reference/ScalaReference.tex b/doc/reference/ScalaReference.tex index 5954615d5b..a53c8798c5 100644 --- a/doc/reference/ScalaReference.tex +++ b/doc/reference/ScalaReference.tex @@ -942,7 +942,7 @@ the type definition Dcl ::= val ValDcl {`,' ValDcl} ValDcl ::= id `:' Type Def ::= val PatDef {`,' PatDef} - PatDef ::= Pattern `=' Expr + PatDef ::= Pattern2 [`:' Type] `=' Expr \end{lstlisting} A value declaration ~\lstinline@val $x$: $T$@~ introduces $x$ as a name of a value of @@ -2915,7 +2915,7 @@ A semicolon preceding the \code{while} symbol of a do loop expression is ignored Enumerator ::= Generator {`;' Enumerator} Enumerator ::= Generator | Expr - Generator ::= val Pattern `<-' Expr + Generator ::= val Pattern1 `<-' Expr \end{lstlisting} A comprehension ~\lstinline@for ($\enums\,$) yield $e$@~ evaluates expression $e$ for each @@ -3241,23 +3241,22 @@ written. \label{sec:patterns} \syntax\begin{lstlisting} -Pattern ::= TreePattern { `|' TreePattern } - -TreePattern ::= varid `:' Type +Pattern ::= Pattern1 { `|' Pattern1 } +Pattern1 ::= varid `:' Type | `_' `:' Type - | SimplePattern [ '*' |'?' | '+' ] - | SimplePattern { id SimplePattern } - +Pattern2 ::= SimplePattern [ '*' |'?' | '+' ] + | SimplePattern { id SimplePattern } SimplePattern ::= varid [ '@' SimplePattern ] | `_' | literal | StableId [ `(' [Patterns] `)' ] | `(' Patterns `)' | - Patterns ::= Pattern {`,' Pattern} \end{lstlisting} +\todo{Why can patterns be empty?} + A pattern is built from constants, constructors, variables and regular operators. Pattern matching tests whether a given value (or sequence of values) has the shape defined by a pattern, and, if it does, binds @@ -4172,7 +4171,7 @@ grammar. Enumerators ::= Generator {`;' Enumerator} Enumerator ::= Generator | Expr - Generator ::= val Pattern `<-' Expr + Generator ::= val Pattern1 `<-' Expr Block ::= {BlockStat `;'} [Expr] BlockStat ::= Import | Def @@ -4184,20 +4183,18 @@ grammar. Constr ::= StableId [TypeArgs] [`(' [Exprs] `)'] - Pattern ::= TreePattern { `|' TreePattern } - - TreePattern ::= varid `:' Type + Pattern ::= Pattern1 { `|' Pattern1 } + Pattern1 ::= varid `:' Type | `_' `:' Type - | SimplePattern [ '*' | '?' | '+' ] + | Pattern2 + Pattern2 ::= SimplePattern [ '*' | '?' | '+' ] | SimplePattern { id SimplePattern } - SimplePattern ::= varid [ '@' SimplePattern ] | `_' | literal | StableId [ `(' [Patterns] `)' ] | `(' Patterns `)' | - Patterns ::= Pattern {`,' Pattern} TypeParamClause ::= `[' TypeParam {`,' TypeParam} `]' |