Re: Basic Lisp Compiler: How to tell which functions to compile?
On Tue, Aug 10, 2010 at 12:43 AM, Jules julesjac...@gmail.com wrote: It is impossible (undecidable) to tell precisely which functions a function will call. Therefore you will need to consider not exactly set of functions that a function will call, but some superset of that. Why not take as your superset all functions? That is, always compile all functions. There is a smaller decidable superset: all functions occurring in the static call graph for a function. But, I agree, most compilers would just compile everything and it's probably a better idea. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Basic Lisp Compiler: How to tell which functions to compile?
Hello everyone, Just for educational purposes, I'm writing a simple lisp compiler and am stuck on a small problem. I'm trying to write a function called (compile-function), which will take a function as input and compile it. If that function calls other functions, I would like (compile- function) to automatically compile the called functions as well. But I'm stuck on how to tell whether a function will be called or not. Particularly when functions are passed around as objects. So the question is this: Given a function f, how can I find all the functions that f depends on? Thanks a lot for your help -Patrick -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Basic Lisp Compiler: How to tell which functions to compile?
On Aug 9, 7:54 pm, CuppoJava patrickli_2...@hotmail.com wrote: Hello everyone, Just for educational purposes, I'm writing a simple lisp compiler and am stuck on a small problem. I'm trying to write a function called (compile-function), which will take a function as input and compile it. If that function calls other functions, I would like (compile- function) to automatically compile the called functions as well. But I'm stuck on how to tell whether a function will be called or not. Particularly when functions are passed around as objects. So the question is this: Given a function f, how can I find all the functions that f depends on? I don't think that's feasible, if it's even possible in the first place. Functions that the parent function calls directly you can of course try to compile whatever you encounter in a function call form; just check if the operator is a known global function, and compile it. However, if the operator is a local variable (ie. a function passed as a parameter) there's no reliable way to find out what function it is. It might even be a runtime-generated function (by eval) Since you can't know what functions will be called, the generated code must somehow verify that it's calling a function in the first place, perhaps invoke the compiler (if all functions must be compiled), and then execute it. -- Jarkko -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Basic Lisp Compiler: How to tell which functions to compile?
Thanks for the reply Jarkko. That helps quite a lot. I have some hacks in place that works most of the time, but was stuck trying to figure out a general solution. Knowing that there isn't one puts my mind at ease. -Patrick On Aug 9, 1:56 pm, Jarkko Oranen chous...@gmail.com wrote: On Aug 9, 7:54 pm, CuppoJava patrickli_2...@hotmail.com wrote: Hello everyone, Just for educational purposes, I'm writing a simple lisp compiler and am stuck on a small problem. I'm trying to write a function called (compile-function), which will take a function as input and compile it. If that function calls other functions, I would like (compile- function) to automatically compile the called functions as well. But I'm stuck on how to tell whether a function will be called or not. Particularly when functions are passed around as objects. So the question is this: Given a function f, how can I find all the functions that f depends on? I don't think that's feasible, if it's even possible in the first place. Functions that the parent function calls directly you can of course try to compile whatever you encounter in a function call form; just check if the operator is a known global function, and compile it. However, if the operator is a local variable (ie. a function passed as a parameter) there's no reliable way to find out what function it is. It might even be a runtime-generated function (by eval) Since you can't know what functions will be called, the generated code must somehow verify that it's calling a function in the first place, perhaps invoke the compiler (if all functions must be compiled), and then execute it. -- Jarkko -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Basic Lisp Compiler: How to tell which functions to compile?
As far as I know, the book Lisp In Small Pieces should be a tremendous help for anyone who builds a Lisp interpreter or compiler. You might want to check it out. On Mon, Aug 9, 2010 at 2:21 PM, CuppoJava patrickli_2...@hotmail.comwrote: Thanks for the reply Jarkko. That helps quite a lot. I have some hacks in place that works most of the time, but was stuck trying to figure out a general solution. Knowing that there isn't one puts my mind at ease. -Patrick On Aug 9, 1:56 pm, Jarkko Oranen chous...@gmail.com wrote: On Aug 9, 7:54 pm, CuppoJava patrickli_2...@hotmail.com wrote: Hello everyone, Just for educational purposes, I'm writing a simple lisp compiler and am stuck on a small problem. I'm trying to write a function called (compile-function), which will take a function as input and compile it. If that function calls other functions, I would like (compile- function) to automatically compile the called functions as well. But I'm stuck on how to tell whether a function will be called or not. Particularly when functions are passed around as objects. So the question is this: Given a function f, how can I find all the functions that f depends on? I don't think that's feasible, if it's even possible in the first place. Functions that the parent function calls directly you can of course try to compile whatever you encounter in a function call form; just check if the operator is a known global function, and compile it. However, if the operator is a local variable (ie. a function passed as a parameter) there's no reliable way to find out what function it is. It might even be a runtime-generated function (by eval) Since you can't know what functions will be called, the generated code must somehow verify that it's calling a function in the first place, perhaps invoke the compiler (if all functions must be compiled), and then execute it. -- Jarkko -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.comclojure%2bunsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Basic Lisp Compiler: How to tell which functions to compile?
It is impossible (undecidable) to tell precisely which functions a function will call. Therefore you will need to consider not exactly set of functions that a function will call, but some superset of that. Why not take as your superset all functions? That is, always compile all functions. On Aug 9, 6:54 pm, CuppoJava patrickli_2...@hotmail.com wrote: Hello everyone, Just for educational purposes, I'm writing a simple lisp compiler and am stuck on a small problem. I'm trying to write a function called (compile-function), which will take a function as input and compile it. If that function calls other functions, I would like (compile- function) to automatically compile the called functions as well. But I'm stuck on how to tell whether a function will be called or not. Particularly when functions are passed around as objects. So the question is this: Given a function f, how can I find all the functions that f depends on? Thanks a lot for your help -Patrick -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
