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| author | Den Shabalin <den.shabalin@gmail.com> | 2013-07-08 20:44:24 +0200 |
|---|---|---|
| committer | Eugene Burmako <xeno.by@gmail.com> | 2013-07-08 21:12:14 +0200 |
| commit | cbe5362a62904a88de78e3b068a544612e46c0cc (patch) | |
| tree | 1f6ebff8e3739751d9c7240678ef366b80f427ab /src/compiler/scala/tools/nsc/ast/parser/Parsers.scala | |
| parent | b5f703f145a17c9cdbfede9192189630c2a9829c (diff) | |
| download | scala-cbe5362a62904a88de78e3b068a544612e46c0cc.tar.gz scala-cbe5362a62904a88de78e3b068a544612e46c0cc.tar.bz2 scala-cbe5362a62904a88de78e3b068a544612e46c0cc.zip | |
adds the lookahead routine to the parser
Introduces a scoping operator used to temporarily look into the future.
Backs up scanner data before evaluating a block and restores it after.
Not used anywhere, only necessary for the upcoming quasiquote patch
in order to reliably detect and accordingly process holes in quasiquoted
Scala syntax.
Diffstat (limited to 'src/compiler/scala/tools/nsc/ast/parser/Parsers.scala')
| -rw-r--r-- | src/compiler/scala/tools/nsc/ast/parser/Parsers.scala | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala index 40439a5379..a89a994377 100644 --- a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala +++ b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala @@ -156,6 +156,17 @@ self => def newScanner(): Scanner = new SourceFileScanner(source) + /** Scoping operator used to temporarily look into the future. + * Backs up scanner data before evaluating a block and restores it after. + */ + def lookingAhead[T](body: => T): T = { + val snapshot = (new ScannerData{}).copyFrom(in) + in.nextToken() + val res = body + in copyFrom snapshot + res + } + val in = newScanner() in.init() |