All Questions
147 questions
1
vote
1
answer
454
views
How to build the antlr grammar provided?
I would like to build a cpp parser using cpp and I'm using ANTLR4. I notice there is this 'grammar' section from the official github antlr grammar github and I've downloaded it. While opening the CPP ...
- 13
-1
votes
1
answer
86
views
How can I fix my ambiguity in bison file? [closed]
I m working on a simple interpreter and I m using bison and flex for my lexer and parser.I have a problem when it comes to the parser :
progr :decl_classes decl_gvars decl_functions block {...
2
votes
1
answer
53
views
Template Circulation Definition
I am creating an intrusive pointer as follows:
class RefCounted {};
template <typename T>
concept RefCountedDerived = std::is_base_of_v<RefCounted, T>;
template <RefCountedDerived T&...
- 95
-3
votes
1
answer
592
views
What is the precedence and associativity of operators?
What is the precedence and associativity of operators in C++?
Who defines operator precedence and associativity, and how does it relate to order of evaluation? explains how those properties emerge ...
- 41.1k
0
votes
1
answer
191
views
Why are curly braces {} NOT considered an operator in C++? [closed]
I've checked official operator list, but didn't see {} appear in any list of operator (either redefinable or non-redefinable).
As far as I know, {} is used to specify a block of code, and also used to ...
- 355
-1
votes
3
answers
793
views
Why is int*& used to declare a reference to a pointer instead of int&*
I thought & and * were just syntactical conventions to declare pointers and references, but when trying to declare a reference to an int*, I have to use int*& otherwise I get this error:
...
- 279
0
votes
2
answers
137
views
mismatched input in ANTLR4
I'm new to ANTLR. I don't see any problem with my grammar, but when I run the parse tree, ANTLR gives me mismatched input message. Could anyone help me explain why I get that?
Here is my lexer
lexer ...
- 45
2
votes
1
answer
118
views
Is (multi-word type name){expression-list} legal?
Consider:
(long long){1};
It’s not a C-style cast expression per [expr.cast]/1:
The result of the expression (T) cast-expression is of type T. The result is an lvalue if T is an lvalue reference ...
0
votes
2
answers
83
views
How to analyze complicated type expressions in C++?
Things seem to become complicated when dealing with compound C++ types.
For example, how to analyze the type of token fp in the codes below?
int *f(int *p, int a)
{
return p + a;
}
int *(*fp())(...
- 23
2
votes
1
answer
277
views
Trying to parse nested expressions with boost spirit x3
My ultimate goal is to write a hlsl shading language parser. My first experience with parsing has been by following bob nystrom's "crafting interpreters".
The issue I am currently facing is ...
0
votes
1
answer
390
views
ANTLR4 parse tree doesn't contain rule names
ANTLR4 doesn't show rule names in parse tree.
For example, 1 + 2 is printed as:
Code in main:
std::string test = "1 + 2";
ANTLRInputStream input(test);
GrammarLexer lexer(&...
- 830
0
votes
2
answers
205
views
for loop IR generation in Bison
Consider the following grammar rule:
forstmt: for openparentheses nexpr semicolon expr semicolon nexpr closeparentheses stmt {}
nexpr: expr { }
| %empty { }
expr: .
.
.
// ...
- 338
0
votes
1
answer
424
views
how to read c++ iso standard? i mean the way
I'm reading n4860 now and i have some curiosity about this.
i don't know how to explain it so i will just show an example.
now i'm looking "unordered_set" and the draft said
template<...
- 387
2
votes
1
answer
107
views
How is C++ syntactic evolution managed?
Separate from frontend implementers' experiences, are there formal standards that syntactic extensions to the C++ grammar are required to meet? That is, are proposed extensions subjected to any form ...
- 1,057
1
vote
0
answers
42
views
language grammar problem for allocate memory in our project
I find a 'new' code in our project, like:
class A
{
public:
A(int x);
};
void func()
{
A* pA = nullptr;
new (pA) A(123); // what is this line meaning?
}
the 'new' function just like
void* ...
- 81