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#pragma once
#include "SrcPos.h"
/**
* Token generated by the tokenizer.
*/
class Token {
public:
Token(const String &token, const SrcPos &pos) : token(token), pos(pos) {}
// Contents of this token.
String token;
// Where is the starting point of this token?
SrcPos pos;
// Compare the actual token.
inline bool operator ==(const Token &o) const { return token == o.token; }
inline bool operator !=(const Token &o) const { return token != o.token; }
inline bool operator ==(const String &o) const { return token == o; }
inline bool operator !=(const String &o) const { return token != o; }
// Empty token?
inline bool empty() const { return token.size() == 0; }
// Is this a string?
bool isStr() const;
// Extract the string from the token. Assumes isStr().
String strVal() const;
};
// Output.
wostream &operator <<(wostream &to, const Token &t);
/**
* Comment generated by the tokenizer.
*/
class Comment {
public:
Comment() : src(null), fileId(0), begin(0), end(0) {}
Comment(const String &src, nat fileId, nat begin, nat end) : src(&src), fileId(fileId), begin(begin), end(end) {}
// Create a string from this comment. This strips all formatting that is applied to the comment,
// such as leading asterisks.
String str() const;
// Any comment at all?
inline bool empty() const { return begin == end; }
inline bool any() const { return begin > end; }
private:
// Source string.
const String *src;
// Source file.
nat fileId;
// Start and end position.
nat begin;
nat end;
// State used when parsing.
enum State {
start,
start2,
done,
// Single line comments.
singleStart,
singleInside,
singleNewline,
singleHalf,
singleBefore,
// Multi line comments.
multiStart,
multiInside,
multiNewline,
multiBefore,
};
// Parameters for the parsing.
struct Params {
// Number of spaces after the comment 'start'.
nat space;
// Current number of spaces.
nat curr;
// Number of empty lines encountered.
nat empty;
};
// Helper for parsing comments.
static const wchar_t *parse(std::wostringstream &to, State &state, Params &par, wchar_t ch);
};
// Output.
wostream &operator <<(wostream &to, const Comment &c);
/**
* Tokenizer designed to properly tokenize the contents of .bnf files.
* Handles strings and basic operators (including ()[] and {}).
* Also handles comments. Comments have the form // ... \n
*/
class Tokenizer : NoCopy {
public:
// Tokenize data in 'SrcPos::files[pathId]' from 'start'.
Tokenizer(nat pathId);
// Get the next token in the stream. Throws an exception if the end of stream
// has been reached.
Token next();
// Skip current token.
void skip();
// Peek.
Token peek();
// More tokens to get?
bool more() const;
// Get a token and see it is the correct one.
void expect(const String &s);
// Skip the current token if it is 'str'.
bool skipIf(const String &s);
// Get the last comment relevant to the current token.
Comment comment() const;
// Clear the current comment.
void clearComment();
private:
// Source string.
const String src;
// Source id.
nat pathId;
// Current position.
nat pos;
// Current SrcPos.
SrcPos srcPos;
// Start and end of the last comment.
nat commentBegin;
nat commentEnd;
// Different states of the tokenizer.
enum State {
sStart,
sText,
sOperator,
sString,
sComment,
sMlComment,
sPreproc,
sPreprocExtend,
sDone,
};
// The next found token.
Token nextToken;
// Find the next token.
Token findNext();
// Do one step in the state-machine.
void processChar(nat &start, State &state, bool &firstComment);
// Advance a srcPos.
void advance(SrcPos &pos, nat from, nat to) const;
};
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