glslang/hlsl/hlslTokenStream.cpp
John Kessenich 1cc1a2813e HLSL: 1) Implement lookahead buffers/stacks for token advance/recede, 2) use it for cast operation.
The grammar now accepts type casts, like "(int)x", but that
has to be disambiguated from "(a + b)", needed deeper lookahead
and backing up than what existed so far.
2016-06-03 16:57:53 -06:00

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//
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#include "hlslTokenStream.h"
namespace glslang {
void HlslTokenStream::pushPreToken(const HlslToken& tok)
{
assert(preTokenStackSize == 0);
preTokenStack = tok;
++preTokenStackSize;
}
HlslToken HlslTokenStream::popPreToken()
{
assert(preTokenStackSize == 1);
--preTokenStackSize;
return preTokenStack;
}
void HlslTokenStream::pushTokenBuffer(const HlslToken& tok)
{
tokenBuffer = tok;
}
HlslToken HlslTokenStream::popTokenBuffer()
{
return tokenBuffer;
}
// Load 'token' with the next token in the stream of tokens.
void HlslTokenStream::advanceToken()
{
pushTokenBuffer(token);
if (preTokenStackSize > 0)
token = popPreToken();
else
scanner.tokenize(token);
}
void HlslTokenStream::recedeToken()
{
pushPreToken(token);
token = popTokenBuffer();
}
// Return the current token class.
EHlslTokenClass HlslTokenStream::peek() const
{
return token.tokenClass;
}
// Return true, without advancing to the next token, if the current token is
// the expected (passed in) token class.
bool HlslTokenStream::peekTokenClass(EHlslTokenClass tokenClass) const
{
return peek() == tokenClass;
}
// Return true and advance to the next token if the current token is the
// expected (passed in) token class.
bool HlslTokenStream::acceptTokenClass(EHlslTokenClass tokenClass)
{
if (peekTokenClass(tokenClass)) {
advanceToken();
return true;
}
return false;
}
} // end namespace glslang