Processing Text in PicoLisp
Hi List, related to the nice idea of publishing the Rosettacode examples (which would actually be nicer _with_ the task descriptions included) I have a few (probably rather newbie) technical questions about manipulating the file-system and processing text in PicoLisp: 1. How to make, concat, and kill files (and directories) on Linux with PicoLisp? Using the system functions? 2. How to realize the following workflow (from Emacs, using Emacs Lisp) in PicoLisp: You open a text file in an Emacs buffer, goto beginning-of-buffer, do a regexp-search for pattern1. Get the point position of the start of pattern1, then delete all the text between beginning-of-buffer and start-of-pattern1. Do another regexp-search for pattern2, get point position of end-of-pattern2. Then treat end-of-pattern2 like beginning-of-buffer and search for start-of-pattern3 etc. The idea is to identify certain blocks in the text and delete everything around them. Thats a very typical task for Emacs Lisp in Emacs, but I'm not quite sure how to do this in PicoLisp. Probably would need a book with all the Rosettacode examples on my desk to easily look it up ;) 3. Is it possible to use 'prog' or 'let' with 'apply', i.e. apply a whole sequence of functions instead of only one to the 'lst argument? Thanks for any tips. -- cheers, Thorsten -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
Re: Processing Text in PicoLisp
Hi Thorsten. Below I've pasted links to descriptions of functions that might or might not be what you want based on a quick glance on your questions: 1.) http://software-lab.de/doc/refC.html#call 2.) http://software-lab.de/doc/refM.html#match 3.) I don't really get this one, isn't it possible for you to simple loop through the functions in questions with for instance for or mapc and then apply them one by one? Hope that helps. /Henrik Sarvell On Mon, Jul 23, 2012 at 10:35 AM, Thorsten Jolitz tjol...@googlemail.comwrote: Hi List, related to the nice idea of publishing the Rosettacode examples (which would actually be nicer _with_ the task descriptions included) I have a few (probably rather newbie) technical questions about manipulating the file-system and processing text in PicoLisp: 1. How to make, concat, and kill files (and directories) on Linux with PicoLisp? Using the system functions? 2. How to realize the following workflow (from Emacs, using Emacs Lisp) in PicoLisp: You open a text file in an Emacs buffer, goto beginning-of-buffer, do a regexp-search for pattern1. Get the point position of the start of pattern1, then delete all the text between beginning-of-buffer and start-of-pattern1. Do another regexp-search for pattern2, get point position of end-of-pattern2. Then treat end-of-pattern2 like beginning-of-buffer and search for start-of-pattern3 etc. The idea is to identify certain blocks in the text and delete everything around them. Thats a very typical task for Emacs Lisp in Emacs, but I'm not quite sure how to do this in PicoLisp. Probably would need a book with all the Rosettacode examples on my desk to easily look it up ;) 3. Is it possible to use 'prog' or 'let' with 'apply', i.e. apply a whole sequence of functions instead of only one to the 'lst argument? Thanks for any tips. -- cheers, Thorsten -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
Re: Processing Text in PicoLisp
Alexander Burger a...@software-lab.de writes: Hi Alex, thanks a lot, thats what I needed to know, now I have to give it a try. 3. Is it possible to use 'prog' or 'let' with 'apply', i.e. apply a whole sequence of functions instead of only one to the 'lst argument? I'm not sure what you mean here. Perhaps it helps to know that the mapping functions take an arbitrary number of lists? Can you give an example? I will try to get as far as I can and then maybe ask again with a better specified question. -- cheers, Thorsten -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
Enhanced ref doc for the 'for' forms
Hi Alex, For quite some time I've felt that the ref. documentation for the 'for' forms could need some improvements. The 'for' function is a very important function, and for most people who are new to PicoLisp, it will be one of the first functions they will have to learn. At the same time, the 'for' function has so many forms and options that a non-Lisper may have a hard time figuring out how to use it. That's why I have tried to enhance the docs for this function. What I've done is (a) inserted a few br line breaks so that the descriptions of the three forms are separated, and so that it will be a little clearer that the sentence starting with If a clause has NIL or T .. may apply to all the three forms. Then (b) I have organized the examples into three groups, one group for each form, adding examples for the first form (that was entirely missing). Take a look at (and copy what you like from) my enhanced docs here: http://folk.uio.no/jkleiser/pico/doc/refF.html#for Please verify that I have done the three example groups correctly. ;-) /Jon -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
Re: Processing Text in PicoLisp
Henrik Sarvell hsarv...@gmail.com writes: Hi Henrik, Below I've pasted links to descriptions of functions that might or might not be what you want based on a quick glance on your questions: 1.) http://software-lab.de/doc/refC.html#call 2.) http://software-lab.de/doc/refM.html#match Thanks, I will look those up (have to get used to do these things without regexp, but it does make sense somehow, since regexp sometimes appear like textbook examples for the meaning og 'cryptic'. 3.) I don't really get this one, isn't it possible for you to simple loop through the functions in questions with for instance for or mapc and then apply them one by one? That question was obviously not well formulated, I think I give it a try now with the info I got and maybe ask again later on based on what I got. -- cheers, Thorsten -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
Re: Enhanced ref doc for the 'for' forms
Hi Jon, For quite some time I've felt that the ref. documentation for the 'for' forms could need some improvements. The 'for' function is a Very true! What I've done is (a) inserted a few br line breaks so that the descriptions of the three forms are separated, and so that it will be a little clearer that the sentence starting with If a clause has NIL or T .. may apply to all the three forms. Then (b) I have organized the examples into three groups, one group for each form, adding examples for the first form (that was entirely missing). Take a look at (and copy what you like from) my enhanced docs here: http://folk.uio.no/jkleiser/pico/doc/refF.html#for Great! You are right, now it is much better. Many thanks! I've incorporated your changes. Cheers, - Alex -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
Upper limit for list lenght in PicoLisp?
Hi List, I have a rather strange problem: I want to (from within Emacs) ,-- | (setq X (list string1 ... string200)) `-- and it seems PicoLisp just freezes - no error messages, but no output either, and the process seems to be frozen. Now when I split the list into , | (setq Y (list string1 ... string100)) | (setq Z (list string101 ... string200)) ` both evaluations work, and quite fast. I could make Y even smaller and Z bigger - until a certain limit (Y = 25, Z = ca. 180 or so), and both assignments work just fine. But when I add both parts together, PicoLisp freezes again when assigning X. Is there something like an upper limit for how many Strings can be in a list in PicoLisp? Or might that be Emacs related? 200 or 300 are not really that big numbers ... -- cheers, Thorsten -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
Re: Upper limit for list lenght in PicoLisp?
Hi Thorsten, Is there something like an upper limit for how many Strings can be in a list in PicoLisp? Or might that be Emacs related? No, there is no limit. Neither to the length of the command line (if you use the built-in line editor). How did you invoke PicoLisp? Does this also happen if you invoke just as $ pil + i.e. PicoLisp alone, without Emacs? Cheers, - Alex -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
Re: Upper limit for list lenght in PicoLisp?
Alexander Burger a...@software-lab.de writes: Hi Alex, Is there something like an upper limit for how many Strings can be in a list in PicoLisp? Or might that be Emacs related? No, there is no limit. Neither to the length of the command line (if you use the built-in line editor). How did you invoke PicoLisp? Does this also happen if you invoke just as $ pil + i.e. PicoLisp alone, without Emacs? No, that works, although there are is someting strange happening too: some of the strings in the list are replaces by NIL, and it seems as if the '\' that signals a linebreak in an Emacs buffer is somehow misinterpreted as an escaping backslash , | wiki/Binary_strings wiki/Bitmap | wiki/Bitmap/Bresenham%27s_line_algorithm | wiki/Bitmap/B%C3%A9zier_curves/Cubic | wiki/Bitmap/B%C3%A9zier_curves/Quadratic wiki/Bitmap/Flood_fill | wiki/Bitmap/Histogram wiki/Bitmap/Midpoint_circle_algorithm | wiki/Bitmap/PPM_conversion_through_a_pipe | wiki/Bitmap/Read_a_PPM_file | wiki/Bitmap/Read_an_image_through_a_pipe | wiki/Bitmap/Write_a_PPM_file wiki/Bitwise_IO | wiki/Bitwise_operations wiki/Boolean_values wiki/Box_the_compass | wiki/Break_OO_privacy wiki/Brownian_tree wiki/Bulls_and_cows | wiki/Bulls_and_cows/Player wiki/Caesar_cipher wiki/Calendar | wiki/Calendar_-_for_%22real%22_programmers | wiki/Call_a_foreign-language_function wiki/Call_a_function | wiki/Call_a_function_in_a_shared_library wiki/Call_an_object_method | wiki/Case-sensitivity_of_identifiers wiki/Catalan_numbers | wiki/Character_codes wiki/Character_matching wiki/Chat_server | wiki/Checkpoint_synchronization wiki/Chess_player | wiki/Chess_player/PicoLisp ` becomes ,-- | wiki/Binary_strings wiki/Bitmap | wiki/Bitmap/Bresenham%27s_line_algorithm\ NIL NIL NIL | NIL NIL NIL NIL NIL NIL NIL NIL NIL | NIL NIL NIL NIL NIL NIL NIL NIL NIL | NIL NIL NIL NIL NIL NIL NIL | \wiki/Chat_server wiki/Checkpoint_synchronization | wiki/Chess_player wiki/Chess_player/PicoLisp `-- So it looks more like an Emacs (PicoLisp mode) related problem. -- cheers, Thorsten -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
Re: Processing Text in PicoLisp
Alexander Burger a...@software-lab.de writes: For making files where you will usually use 'out', and write directly to the file. To concat two files, you could do: (out c (in a (echo)) (in b (echo))) Erasing a file is not implemented as a PicoLisp function. You can simply call 'rm' (call 'rm c) Is there a way to make 'out' write directories too? ,- | (out /new/dir/newfile (in a (echo)) (in b (echo))) `- (This doesn't work for me) Or do I have to use something like ,-- | (call 'mkdir /new/dir/) `-- then ,--- | (call 'cd /new/dir/) `--- then , | (out newfile (in a (echo)) (in b (echo))) | ` ? -- cheers, Thorsten -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
Re: Upper limit for list lenght in PicoLisp?
Alexander Burger a...@software-lab.de writes: Hi Alex, You said that you call it as (setq X (list string1 ... string200)) Note that this evaluates the transient symbols string1 etc., so if one of them has a value NIL (or anything else), it will be included in the list. What you actually want to do is (setq X '(string1 ... string200)) yes, definitely... thanks -- cheers, Thorsten -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
Re: Processing Text in PicoLisp
AFAIK out doesn't do auto dir creation or any dir creation for that matter. Looks good but the cd thing should not be necessary, just use the absolute path in the last call. Note that you can use info to check stuff, could possibly be used in a function that checks a certain path from top to bottom and creates any missing dirs on the way. Ie if new exists it will create dir. On Mon, Jul 23, 2012 at 10:15 PM, Thorsten Jolitz tjol...@googlemail.comwrote: Alexander Burger a...@software-lab.de writes: For making files where you will usually use 'out', and write directly to the file. To concat two files, you could do: (out c (in a (echo)) (in b (echo))) Erasing a file is not implemented as a PicoLisp function. You can simply call 'rm' (call 'rm c) Is there a way to make 'out' write directories too? ,- | (out /new/dir/newfile (in a (echo)) (in b (echo))) `- (This doesn't work for me) Or do I have to use something like ,-- | (call 'mkdir /new/dir/) `-- then ,--- | (call 'cd /new/dir/) `--- then , | (out newfile (in a (echo)) (in b (echo))) | ` ? -- cheers, Thorsten -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
Re: Processing Text in PicoLisp
Henrik Sarvell hsarv...@gmail.com writes: AFAIK out doesn't do auto dir creation or any dir creation for that matter. ok Note that you can use info to check stuff, could possibly be used in a function that checks a certain path from top to bottom and creates any missing dirs on the way. Ie if new exists it will create dir. didn't know about info, thats definitely usefull, thanks -- cheers, Thorsten -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
Re: Processing Text in PicoLisp
Hi Thorsten, Is there a way to make 'out' write directories too? No, 'out' just creates or opens a file for writing. Or do I have to use something like ,-- | (call 'mkdir /new/dir/) `-- Yes. But this works only if /new/ already exists. If /new/ is also missing, you can create the complete path with (call 'mkdir -p /new/dir/) (BTW, do you really want to write to the root directory /?) ,--- | (call 'cd /new/dir/) `--- then , | (out newfile (in a (echo)) (in b (echo))) | ` No. 'cd' is a shell builtin, and cannot be used wit 'call'. There are two lisp functions for that, 'cd' and 'chdir' (cd /new/dir/) or (chdir /new/dir/ .. body ..) The difference is that 'chdir' executes the body and then restores the original working directory (also if an exception (throw) occurs within the body). (chdir /new/dir/ (out newfile ..)) But in general I would be careful with 'cd' and 'chdir', as it modifies the working directory of the whole process. For example, a and b above will not be found (as the directory is new), and you must use ../../a or something like that. Better is usually to call (let Dir /new/dir/ (call 'mkdir -p Dir) (out (pack Dir newfile) (in a ...)) ) Cheers, - Alex -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
