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1. Top results related to what are the function of dictionary in c compiler and interpreter design

   • What are the differences between using pure C with a C compiler and the "C part" of a C++ compiler?

     Top Answer

     Answered Sep 06, 2010 · 34 votes

     There are a lot of minor nitpicks. One that strikes me as being the most obvious is that in C++, you have to cast the return value of malloc. Also structs are automatically typedefed in C++.

     Always use a C compiler for C code, not C++. C++ isn't perfectly compatible with C.

     A few others:

     • In C, declaring void func(); declares a function that hasn't specifed what its arguments are, whereas in C++, void func(); is equivalent to the C void func(void)', taking no arguments;
     • Prototypes are required in C++, whereas it's generally just a warning in C;
     • The type of character constants (like 'a') is int in C and char in C++;
     • The type of string literals is char [] in C and const char [] in C++;
     • Some legitimate variable names in C, like class, are reserved keywords in C++.

     For all those who don't believe me and are downvoting, check out this C code:

     #include <stdlib.h>-int main(int argc, char **argv) { int *i = malloc(sizeof(int));- return 0;}-

     Compilation under gcc is fine, but compilation under g++ gives the following errors:

     test.c: In function `int main(int, char**)':test.c:4: error: invalid conversion from `void*' to `int*'-

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     1/5

   • What are the Roles of Java Compiler and Interpreter?

     Compiler and Interpreter are two different ways to translate a program from programming or scripting language to machine language. In this article let’s discuss on what are the roles of the Compiler and Interpreter in Java.

     Java Compiler

     A compiler in Java translates the entire source code into a machine-code file or any intermediate code, and that file is then executed. It is platform-independent. A bytecode is basically an intermediate code generated by the compiler after the compilation of its source code. Java compiler can be operated by using the “Javac.exe” command from the command prompt. Some of the compiler options are given below:

     • -help: it prints a summary of standard options.
     • -version: returns the compiler information.
     • -verbose: verbose output i.e., it includes information about each source file compiled and each class loaded.
     • -nowarn: it is used to turn off warnings. 

      

     Java Compiler Step By Step

      

     Roles of...

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     2/5

   • What are the Roles of Java Compiler and Interpreter?

     Compiler and Interpreter are two different ways to translate a program from programming or scripting language to machine language. In this article let’s discuss on what are the roles of the Compiler and Interpreter in Java.

     Java Compiler

     A compiler in Java translates the entire source code into a machine-code file or any intermediate code, and that file is then executed. It is platform-independent. A bytecode is basically an intermediate code generated by the compiler after the compilation of its source code. Java compiler can be operated by using the “Javac.exe” command from the command prompt. Some of the compiler options are given below:

     • -help: it prints a summary of standard options.
     • -version: returns the compiler information.
     • -verbose: verbose output i.e., it includes information about each source file compiled and each class loaded.
     • -nowarn: it is used to turn off warnings. 

      

     Java Compiler Step By Step

      

     Roles of...

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     3/5

   • What are the different between calling constructor and calling function pointer of constructor in C++

     Top Answer

     Answered Jan 28, 2024 · 0 votes

     Calling a constructor and calling a function pointer of a constructor in C++ are very similar in the sense that they are both quite impossible:

     • You cannot call a constructor in C++.
     • You cannot obtain a pointer to a constructor in C++.

     According to the C++ spec about constructors:

     Constructors have no names and cannot be called directly.

     So, in C++, you do not call constructors. The language does that for you when you use the new keyword, when you declare an object on the stack, etc. The expression new MyClass() might look like a constructor invocation, and it does in fact contain a constructor invocation, and so it might be mistaken for a constructor invocation, but that's not what it is; it is a "new expression", which includes, among other things, an invocation of a constructor. But the other things are crucial: you cannot just skip them and directly invoke the constructor.

     Function pointers of constructors do not exist because normally you cannot take the address of a constructor. If you examine the names exported by the DLL, and somehow figure out which name corresponds to the constructor, and use that name to obtain the entry point of that constructor from the DLL, you are cheating: you are doing something which is not normally supported by the language. As a result, you should not attempt to invoke that entry point. A constructor is only supposed to be invoked by the language.

     Also according to the C++ spec:

     A constructor is a special non-static member function of a class.

     (Emphasis mine.)

     A constructor assumes that memory has been allocated, and proceeds to initialize that memory. The language takes care of the memory allocation, but invoking the constructor directly does not. Since a constructor is non-static, it expects an uninitialized this to be passed to it, but you are not allocating any memory and you are not passing anything to the constructor. The result is exactly as expected: a crash.

     And besides, think about it: the constructor could not be internally allocating the memory, because how would it work then if the object was allocated on the stack? And how would it work if the constructor was being invoked by the constructor of a derived class which presumably occupies more memory?

     You can get your DLL to work by using a factory method. A factory method is a public static method which executes new ClassA() and returns the result, or declares ClassA() and returns it by value. Then, obtain the address of the factory method from the DLL, and invoke it.

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   • What are the differences between a Just-in-Time-Compiler and an Interpreter?

     Top Answer

     Answered Mar 11, 2010 · 38 votes

     Just-in-time compilation is the conversion of non-native code, for example bytecode, into native code just before it is executed.

     From Wikipedia:

     JIT builds upon two earlier ideas in run-time environments: bytecode compilation and dynamic compilation. It converts code at runtime prior to executing it natively, for example bytecode into native machine code.

     An interpreter executes a program. It may or may not have a jitter.

     Again, from Wikipedia:

     An interpreter may be a program that either

     • executes the source code directly
     • translates source code into some efficient intermediate representation (code) and immediately executes this
     • explicitly executes stored precompiled code made by a compiler which is part of the interpreter system

     Both the standard Java and .NET distributions have JIT compilation, but it is not required by the standards. The JIT compiler in .NET and C# are of course different because the intermediate bytecode is different. The principle is the same though.

     Other Answers

     Answered Nov 18, 2014 · 60 votes

     I've always found that a more abstract explanation sometimes helps. Let's say that you are trying to ask everyone in Mexico "Hello. How are you?" (your source language) Of course, you'll first need to translate it to Spanish (the native language of the country). That translation would be "Hola. Como estas?"

     If you know Spanish, there would be no need for you to translate (native code / assembler). You just ask "Hola. Como estas?"

     If you don't know Spanish, there are 3 ways to deal with it.

     The first is to get a Spanish Dictionary (a compiler) and look up what the Spanish words are before you go. Perhaps you realize that "Hola. Que tal?" is one syllable shorter (compiler optimization) and use that instead. This is language compilation; you are converting the information to the native language beforehand.

     The second is where you look up the words in the Spanish Dictionary while you are standing in front of the first person and then store the result (looking up the words just-in-time). The advantage here is that you could get a Mandarin Dictionary and then do the same experiment in China without having to keep ten sticky notes (binaries for different platforms) of translated phrases.

     The third is where you look up the words while you are standing in front of each person. In essence, you interpret the words for each person separately (you act as an interpreter). The advantage here is that any changes are instantly reflected with the next person (you could change to asking "Hello. What color is your dog?" without having to fly home and restart - you don't need to recompile the phrases).

     • Translating beforehand means you can ask people fastest (pre-compiliation); you don't need to even bring the dictionary with you.
     • Translating when you see the first person in each country is almost as fast as translating beforehand but still allows you to travel to multiple countries without needing to go home to get a dictionary but means that you need to bring several dictionaries with you (a platform independent runtime).
     • Translating on demand is much slower but allows you to change the words without traveling home (source distributed language).

     Other Answers

     Answered Mar 24, 2016 · 24 votes

     An interpreter generates and executes machine code instructions on the fly for each instruction, regardless of whether it has previously been executed. A JIT caches the instructions that have been previously interpreted to machine code, and reuses those native machine code instructions thus saving time & resources by not having to re-interpret statements that have already been interpreted.

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2. www.geeksforgeeks.org › implementation-on-map-orImplementation on Map or Dictionary Data Structure in C

   www.geeksforgeeks.org › implementation-on-map-or

   • Cached

   Mar 27, 2023 · Functions used to implement Map in C. The getIndex function searches for a key in the keys array and returns its index if found, or -1 if not found. The insert function inserts a key-value pair into the map. If the key already exists, it updates the value. The get function returns the value of a key in the map, or -1 if the key is not found.

3. stackoverflow.com › questions › 4384359data structures - Quick Way to Implement Dictionary in C ...

   stackoverflow.com › questions › 4384359

   • Cached

   Section 6.6 of The C Programming Language presents a simple dictionary (hashtable) data structure. I don't think a useful dictionary implementation could get any simpler than this. For your convenience, I reproduce the code here. struct nlist { /* table entry: */. struct nlist *next; /* next entry in chain */. char *name; /* defined name */.

   Code sample

   struct nlist {

     struct nlist *next;

     char *name;

     char *defn;

   };...

   See more on stackoverflow

4. People also ask

   What is the difference between compiler and interpreter?

   • An interpreter translates one line at a time and then executes it. Example: Perl, Python and Matlab. A compiler is a program that converts the entire source code of a programming language into executable machine code for a CPU. An interpreter takes a source program and runs it line by line, translating each line as it comes to it.

   Language Processors: Assembler, Compiler and Interpreter

   www.geeksforgeeks.org/language-processors-assembler-compiler-and-interpreter/

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   Does C# use both compiler and interpreter?

   • It takes the program, one line at a time, and translates each line before running it: It translates the first line and runs it, then translates the second line and runs it etc. Compiler characteristics: Interpreter characteristics: so c# uses both compiler and interpreter? That's not correct. Both languages are both compiled and interpreted.

   How does an interpreter/compiler work - Stack Overflow

   stackoverflow.com/questions/2377273/how-does-an-interpreter-compiler-work

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   What does a compiler do?

   • Compiler The language processor that reads the complete source program written in high-level language as a whole in one go and translates it into an equivalent program in machine language is called a Compiler. Example: C, C++, C#. In a compiler, the source code is translated to object code successfully if it is free of errors.

   Language Processors: Assembler, Compiler and Interpreter

   www.geeksforgeeks.org/language-processors-assembler-compiler-and-interpreter/

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   Do I need an interpreter if I compile a program?

   • If you compile a program into something the machine understands, then you dont need an interpreter. Moreover, the point of the question is the difference between the object code produced by a compiler and the midcode (eg: bytecode) produced for example by a Java compiler that is then interpreted by a real Interpreter each time its run.

   How does an interpreter/compiler work - Stack Overflow

   stackoverflow.com/questions/2377273/how-does-an-interpreter-compiler-work

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5. www.geeksforgeeks.org › language-processorsLanguage Processors: Assembler, Compiler and Interpreter

   www.geeksforgeeks.org › language-processors

   • Cached

   Mar 8, 2024 · Interpreter. A compiler is a program that converts the entire source code of a programming language into executable machine code for a CPU. An interpreter takes a source program and runs it line by line, translating each line as it comes to it. The compiler takes a large amount of time to analyze the entire source code but the overall execution ...

6. www3.nd.edu › ~dthain › compilerbookSecond Edition Prof. Douglas Thain - University of Notre Dame

   www3.nd.edu › ~dthain › compilerbook

   Introduction to Compilers and Language Design Second Edition Prof. Douglas Thain University of Notre Dame

   • File Size: 1MB

   • Page Count: 247

7. rdw.rowan.edu › cgi › viewcontentCompiler Design: Theory, Tools, and Examples - Rowan University

   rdw.rowan.edu › cgi › viewcontent

   The concepts of compiler design are applied to a case study which is an implementation of a subset of Java which I call Decaf. Chapters 2, 4, 5, and 6 each include a section devoted to explaining how the relevant part of the Decaf compiler is designed. This public domain software is presented in full in the appendices and is available on the ...

8. www.cs.usfca.edu › ~galles › compilerdesignModern Compiler Design - University of San Francisco

   www.cs.usfca.edu › ~galles › compilerdesign

   in the body of yywrap instead of in the main program, without changing the output of the program. Also, since the regular expressions: . \n. { printf("%s",yytext); } { printf("%s", yytext); } just implement the default action, we could remove them without affecting the output of our program.

9. www.cs.toronto.edu › Week7-Compilers-LibrariesCompilers, Interpreters, Libraries - Department of Computer ...

   www.cs.toronto.edu › Week7-Compilers-Libraries

   Compiler vs. Interpreter • Somehow we need to convert a program into machine code (object code). • A compiler passes over a whole program before translating it into object code. • An interpreter reads and executes one line of code at a time. • An interpreter is a compiled program (often written in C).