interpreter

问题 So these questions came to mind because (due to adding an extra zero in a call to a power function) I learned that the python "int" type can be arbitrarily large, atleast until the interpreter runs out of memory to allocate. That prompted me to do an experiment: import sys n = 10000 print(2 ** n) print(len(str(2 ** n))) print(type(2 ** n)) print(sys.maxsize) print(len(str(sys.maxsize))) print(type(sys.maxsize)) This generates the output:

问题 In a Scala code, I'd like to create an interpreter that will evaluate some strings which are Scala code, e.g., using ScriptEngine. But I'd like to pass the current variable and type definitions to it so that the code in the strings can use them, as if the new interpreter is forked from the current interpreter. With ScriptEngine I could use use the "put" method to put bindings into it, but this needs to be explicit and for each variable. And, there's no way to pass a class definition, or a

问题 I've been writing up a micro-mini-lisp based on the encoding in minilisp, the McCarthy paper (as emended by the Roots of Lisp), and using a (possibly objectionable) style based on the J Incunabulum. And using the PP_NARG macro from here. I was also motivated by my previous project, a codegolf'ed lambda calculus interpreter which I later discovered to be eerily similar to the 1999 ioccc Lisp interpreter, particularly in the use of cursors rather than pointers to refer to memory addresses. It

问题 How are functions stored in a variable? According to MDN In JavaScript, functions are first-class objects, because they can have properties and methods just like any other object. What distinguishes them from other objects is that functions can be called. In brief, they are Function objects. Suppose this scenario, var fn = function () {}; fn.attr = 3; console.log(fn); //prints function() {} console.log(Object.keys(fn)); //prints ["attr"] If a function is an object shouldn't it have keys and

问题 In section 4, Tables, in The Implementation of Lua 5.0 there is and example: local t = {100, 200, 300, x = 9.3} So we have t[4] == nil . If I write t[0] = 0 , this will go to hash part . If I write t[5] = 500 where it will go? Array part or hash part ? I would eager to hear answer for Lua 5.1, Lua 5.2 and LuaJIT 2 implementation if there is difference. 回答1: Contiguous integer keys starting from 1 always go in the array part. Keys that are not positive integers always go in the hash part.

问题 As the title indicates, are there any C/C++ bytecode compilers/interpreters? I'm writing an application in an interpreted language that depends on certain libraries that are fully cross-compilable (there are no special flags to indicate code changes during compilation for a certain platform) but are written in C and C++. Rather than shipping n-platform-specific-libs with each platform, it would be nice to ship one set of libs which are interpreted by one platform specific interpreter.

问题 I am trying to make a small interpreting program with JavaScript/jQuery. So what I want is that when the user enter some text in the textarea the program should interpret that text and print the output in another text area. Till now I have achieved this: https://jsfiddle.net/7462hbv1/ With this I am able to catch each of the string that the user inputs in the text area. But now I want that when the user for example enter: number a =1 number b=2 number sum=0 sum =a +b print sum the program

问题 I am looking in to the performance issues of the loop like structures in Python and found the following statements: Besides the syntactic benefit of list comprehensions, they are often as fast or faster than equivalent use of map. (Performance Tips) List comprehensions run a bit faster than equivalent for-loops (unless you're just going to throw away the result). (Python Speed) I am wondering what difference under the hood gives list comprehension this advantage. Thanks. 回答1: Test one :

问题 I need to develop an application that will read and understand text file in which I'll find a custom language that describe a list of operations (ie cooking recipe). This language has not been defined yet, but it will probably take one of the following shape : C++ like code (This code is randomly generated, just for example purpose) : begin repeat(10) { bar(toto, 10, 1999, xxx); } result = foo(xxxx, 10); if(foo == ok) { ... } else { ... } end XML code (This code is randomly generated, just

问题 I've a DSL written using Xtext. What I want is to execute that DSL to perform something good out of it. I wrote myDslGenerator class implementing the interface IGenerator in xtend to generate java code and it's working fine. I've two questions; What is the difference between Interpreter and Code Generator? Aren't both for executing DSL? How to write an interpreter? Any step by step tutorial link? I found many tutorial to generate code using xtend but couldn't find any for writing an