Revision: 18050
Author: [email protected]
Date: Mon Nov 25 13:12:41 2013 UTC
Log: Experimental scanner: Add base class ScannerBase.
This way Parser and PreParser can hold a ScannerBase*, which points to the
implementation of ScannerBase for the current encoding.
The work is done in pure virtual Scan(); the implementation of Scan is
specialized for each encoding.
[email protected]
BUG=
Review URL: https://codereview.chromium.org/85733002
http://code.google.com/p/v8/source/detail?r=18050
Modified:
/branches/experimental/parser/src/lexer/experimental-scanner.h
=======================================
--- /branches/experimental/parser/src/lexer/experimental-scanner.h Mon Nov
25 12:59:45 2013 UTC
+++ /branches/experimental/parser/src/lexer/experimental-scanner.h Mon Nov
25 13:12:41 2013 UTC
@@ -57,35 +57,39 @@
class UnicodeCache;
-struct ScannerLocation {
- ScannerLocation(int b, int e) : beg_pos(b), end_pos(e) { }
- ScannerLocation() : beg_pos(0), end_pos(0) { }
+// Base class for scanners for different encodings. The meat is the pure
virtual
+// Scan() which each of them specializes.
+class ScannerBase {
+ public:
+ struct Location {
+ Location(int b, int e) : beg_pos(b), end_pos(e) { }
+ Location() : beg_pos(0), end_pos(0) { }
- bool IsValid() const {
- return beg_pos >= 0 && end_pos >= beg_pos;
- }
+ bool IsValid() const {
+ return beg_pos >= 0 && end_pos >= beg_pos;
+ }
- static ScannerLocation invalid() { return ScannerLocation(-1, -1); }
+ static Location invalid() { return Location(-1, -1); }
- int beg_pos;
- int end_pos;
-};
+ int beg_pos;
+ int end_pos;
+ };
-template<typename YYCTYPE>
-class ExperimentalScanner {
- public:
- explicit ExperimentalScanner(
- YYCTYPE* source,
- YYCTYPE* source_end,
- Isolate* isolate);
+ explicit ScannerBase(Isolate* isolate)
+ : unicode_cache_(isolate->unicode_cache()),
+ has_line_terminator_before_next_(true),
+ harmony_numeric_literals_(false),
+ harmony_modules_(false),
+ harmony_scoping_(false) {
+ }
- ~ExperimentalScanner();
+ virtual ~ScannerBase() { }
// Returns the next token and advances input.
Token::Value Next() {
has_line_terminator_before_next_ = false;
current_ = next_;
- Scan(); // will fill in next_.
+ Scan(); // Virtual! Will fill in next_.
return current_.token;
}
@@ -94,14 +98,16 @@
// Returns the location information for the current token
// (the token last returned by Next()).
- ScannerLocation location() {
- return ScannerLocation(current_.beg_pos, current_.end_pos);
+ Location location() {
+ return Location(current_.beg_pos, current_.end_pos);
}
// One token look-ahead (past the token returned by Next()).
Token::Value peek() const { return next_.token; }
- ScannerLocation peek_location() const { return next_.location; }
+ Location peek_location() const {
+ return Location(next_.beg_pos, next_.end_pos);
+ }
UnicodeCache* unicode_cache() { return unicode_cache_; }
@@ -170,8 +176,8 @@
uc32 ScanOctalEscape(uc32 c, int length) { return 0; } // FIXME
- ScannerLocation octal_position() const {
- return ScannerLocation(0, 0); // FIXME
+ Location octal_position() const {
+ return Location(0, 0); // FIXME
}
void clear_octal_position() { } // FIXME
@@ -184,30 +190,28 @@
// be empty).
bool ScanRegExpFlags() { return false; } // FIXME
- private:
+ protected:
struct TokenDesc {
Token::Value token;
int beg_pos;
int end_pos;
};
- void Scan();
+ virtual void Scan() = 0;
+ virtual uc32 ScanHexNumber(int length) = 0;
- bool ValidIdentifierStart();
- bool ValidIdentifierPart();
- uc32 ScanHexNumber(int length);
+ bool ValidIdentifierPart() {
+ return unicode_cache_->IsIdentifierPart(ScanHexNumber(4));
+ }
+
+ bool ValidIdentifierStart() {
+ return unicode_cache_->IsIdentifierStart(ScanHexNumber(4));
+ }
UnicodeCache* unicode_cache_;
- YYCTYPE* buffer_;
- YYCTYPE* buffer_end_;
- YYCTYPE* start_;
- YYCTYPE* cursor_;
- YYCTYPE* marker_;
bool has_line_terminator_before_next_;
- YYCTYPE yych;
-
TokenDesc current_; // desc for current token (as returned by Next())
TokenDesc next_; // desc for next token (one token look-ahead)
@@ -216,23 +220,41 @@
bool harmony_scoping_;
};
-const byte* ReadFile(const char* name, Isolate* isolate, int* size, int
repeat);
+
+template<typename YYCTYPE>
+class ExperimentalScanner : public ScannerBase {
+ public:
+ explicit ExperimentalScanner(
+ YYCTYPE* source,
+ YYCTYPE* source_end,
+ Isolate* isolate);
+
+ virtual ~ExperimentalScanner();
+
+ virtual void Scan();
+ virtual uc32 ScanHexNumber(int length);
+
+ private:
+ YYCTYPE yych;
+ YYCTYPE* buffer_;
+ YYCTYPE* buffer_end_;
+ YYCTYPE* start_;
+ YYCTYPE* cursor_;
+ YYCTYPE* marker_;
+};
+
template<typename YYCTYPE>
ExperimentalScanner<YYCTYPE>::ExperimentalScanner(
YYCTYPE* source,
YYCTYPE* source_end,
Isolate* isolate)
- : unicode_cache_(isolate->unicode_cache()),
- has_line_terminator_before_next_(true),
- harmony_numeric_literals_(false),
- harmony_modules_(false),
- harmony_scoping_(false) {
- buffer_ = source;
- buffer_end_ = source_end;
- start_ = buffer_;
- cursor_ = buffer_;
- marker_ = buffer_;
+ : ScannerBase(isolate),
+ buffer_(source),
+ buffer_end_(source_end),
+ start_(source),
+ cursor_(source),
+ marker_(source) {
Scan();
}
@@ -258,18 +280,7 @@
}
return x;
}
-
-
-template<typename YYCTYPE>
-bool ExperimentalScanner<YYCTYPE>::ValidIdentifierPart() {
- return unicode_cache_->IsIdentifierPart(ScanHexNumber(4));
-}
-
-template<typename YYCTYPE>
-bool ExperimentalScanner<YYCTYPE>::ValidIdentifierStart() {
- return unicode_cache_->IsIdentifierStart(ScanHexNumber(4));
-}
} }
--
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