Questions tagged [language-specifications]
126 questions
3
votes
1 answer
What variable is being referred to here?
class Test {
int a;
void method() {
a = 1;
int a = a = 2;
a = 3;
}
}
There are lots of as in method. What are they all referring to?
Andy Turner
- 137,514
- 11
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3
votes
1 answer
Why is the Java class file format missing constant pool tag 2?
The JVM specification for Java 1.0.2 lists the following constant pool entry types:
+-----------------------------+-------+
| Constant Type | Value |
+-----------------------------+-------+
| CONSTANT_Class | 7 |
|…
0xbe5077ed
- 4,565
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3
votes
2 answers
Why can you import a class with the same name as a nested class?
Consider the following code:
import java.util.Calendar;
class Demo
{
class Calendar {}
public static void main (String[] args) {
// System.out.println(Calendar.DAY_OF_WEEK); // Would be an error.
}
}
This code compiles fine;…
Andy Turner
- 137,514
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3
votes
4 answers
Why is null check performed after argument list evaluation?
According to C# Language Specification 7.4.3 Function member invocation the runtime processing of function member invocation consists of the following steps, where M is instance function member declared in a reference-type, E is the instance…
Andrew Karpov
- 431
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- 7
3
votes
1 answer
What defect report is Sean Parent referring to in his GBC - Implement Complete Types talk
In Sean Parent's talk Goals for Better Coding - implement Complete Types at 44:10-44:50 Sean says something to the effect of
If I put this [class with a copy assignment operator that accepts its
parameter by value, and also has a move…
SCFrench
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3
votes
1 answer
Is this a typo in the Scala Language Specification on Parameterized Types?
Should U_i not be rather T_i, as shown in the picture below ?
The same typo (IMHO) is also here.
If it is not a typo, then could someone please tell me where the meaning of T_i is specified ?
jhegedus
- 20,244
- 16
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3
votes
1 answer
According to the Scala Language Specification, packages are AnyRef values and have types. How does this make sense?
I am reading through the Scala Language Specification and I have encountered something confusing, namely, the implication that packages are values and they do have types.
Here is how I concluded (maybe incorrectly?) this strange fact from the Scala…
jhegedus
- 20,244
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3
votes
1 answer
Does a syntax-rules expression by itself evaluate to a value in Scheme?
In Chibi and CHICKEN, the following syntax-rules expression evaluates to a procedure:
(syntax-rules () ((_) #f))
Is this just an artifact of how these particular implementations are written? The Scheme language specs do not seem to call out…
Justin Ethier
- 131,333
- 52
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3
votes
0 answers
Is there a language (or language spec) to extract elements from a DAG
I have a problem where I have a huge number of DAGs and I have to visit each DAG, and extract many different sets of items.
This may sound a bit abstract so let me use an example. Xpath or JSONPath are languages that specify how i can extract an…
Vishnu
- 521
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3
votes
1 answer
ACSL specification for a possibly infinite C function
I am trying to specify the behavior of external functions, more precisely, their termination. The ACSL documentation says that the \terminates p; property specifies that if the predicate p holds, then the function is guaranteed to terminate, but…
Anne
- 1,270
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2
votes
2 answers
Is there a specification or standard for Rust?
Is there a specification or standard for Rust? Kind of like the ECMAScript specification for JavaScript?
I found https://github.com/rust-lang/reference, and it says:
This document is not normative. It may include details that are specific to rustc…
user584011
- 41
- 4
2
votes
3 answers
What part of ECMAScript spec mandates that String type is immutable?
I know that String primitive type in Javascript is immutable, via practice and word of mouth. But what combination of rules in the ECMA-262 makes it so? More specifically, why the second line in the following example silently does nothing?
const str…
hijarian
- 2,159
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2
votes
4 answers
is deciding the causality requirements of the java memory model tractable?
The Java Language Specification provides criteria for determining whether a (well-formed) execution satisfies "the causality requirement for the Java memory model". Let's assume that the execution is finite. I'm trying to understand if there's a…
Just Me
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2
votes
3 answers
Can this be legally be done in C++?
Note: the following code is illegal, but a conforming compiler is not required to reject it (and some don't).
In a library I'm working with I have a template function declaration for Foo and a template function definition for Bar in…
BCS
- 75,627
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2
votes
1 answer
Java Specification: reads see writes that occur later in the execution order
I'm now reading Java Language Specification.
§17.4.5-1 said
In this execution, the reads see writes that occur later in the execution order. This may seem counterintuitive, but is allowed by happens-before consistency. Allowing reads to see later…
Dean Xu
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