Regular Expressions in OCaml - regex

I want to use regexps in OCaml and it seems that Str module provides these functionalities.
So I tried with a simple program:
open Str
let regx = regexp "."
but it gives me the following error
File "lol.ml", line 1, characters 0-1:
Error: Error while linking lol.cmo:
Reference to undefined global `Str'
As if module is not present but if I remove open Str it says that regexp is an unbound value.
I don't get what kind of issue it is, Str should be a standard module (according to http://caml.inria.fr/pub/docs/old-311/libref/Str.html) so I'm clueless.. the only think I thought is that signature (mli) is present but implementation (ml) is not.
I'm running Objective Caml version 3.11.0 according to ocaml tool.
Can anyone help me figuring this out?
Thanks in advance

From the manual:
Programs that use the str library must be linked as follows:
ocamlc other options str.cma other files
ocamlopt other options str.cmxa other files

Or you can put
#load "str.cma";;
if you are doing it in the interpreter

As an alternative to the Str module there's also Re2.
Install it using opam install re2
Use the module in your_file.ml like this:
open Re2.Std
open Re2.Infix
let change input_text = Re2.rewrite_exn ~/"change this" "to that" input_text
let () = printf "%s" (change "change this")
Compile with ocamlbuild -use-ocamlfind -package re2 -package core -tag thread your_file.byte

Related

Frama-C Aluminum "Unbound module GMenu"

On Fedora 21, I compiled the Frama-C Aluminum distribution from source after installing all its prerequisites. My version of OCaml is 4.02.3. Frama-C and the Frama-C GUI work fine. I am trying to follow section 2.3, "The ViewCfg plug-in" of the Frama-C Plug-In Development Guide. However, in section 2.3.4, "Extending the Frama-C GUI", after I add the GUI extension code and run it using the "-load-script" option, I get the following message:
File "cfg_print.ml", line 87, characters 19-43:
Error: Unbound module GMenu
[kernel] user error: compilation of 'cfg_print.ml' failed
Lines 86-87 read:
let cfg_selector
(popup_factory:GMenu.menu GMenu.factory) main_ui ~button:_ localizable =
I googled "unbound module gmenu" but didn't find anything useful. I also never ran into this error while using the Neon and Sodium versions of Frama-C. Interestingly, if I skip that section and follow section 2.3.5, "Splitting files and writing a Makefile", I no longer get the "Unbound module GMenu" message, and the example works fine.
If I had to guess, when I use the "-load-script" option, Frama-C (or my version of OCaml, whatever the case may be) apparently cannot find the Gtk libraries for some reason. But if I use make, OCaml can find the Gtk libraries. Is there something possibly wrong with the way I installed Frama-C and/or the Gtk libraries? How can I check this, or more importantly, how can I fix this?
Your Frama-C installation is probably ok. What you observe is a bug that was introduced when we transitioned to OCamlfind. We will fix it for Frama-C Silicium.
In case you really want to use a script, here is the patch that you need to apply to the sources of Frama-C:
--- a/src/kernel_services/plugin_entry_points/dynamic.ml
+++ b/src/kernel_services/plugin_entry_points/dynamic.ml
## -236,7 +236,7 ## let load_script base =
else
Format.fprintf fmt "%s -c" Config.ocamlc ;
Format.fprintf fmt " -w Ly -warn-error A -I %s" Config.libdir ;
- if !Config.is_gui then Format.pp_print_string fmt " -I +lablgtk" ;
+ if !Config.is_gui then Format.pp_print_string fmt " -package lablgtk2" ;
List.iter (fun p -> Format.fprintf fmt " -I %s" p) !load_path ;
Format.fprintf fmt " %s.ml" base ;
Format.pp_print_flush fmt () ;

Compiling program that uses Lwt_term

I have the following code in OCaml:
open Lwt
open Lwt_term
let () = Lwt_main.run (
lwt l = Lwt_read_line.read_line ~prompt:[text "foo> "] ())
when I try to compile using
ocamlfind ocamlc -package lwt cli.ml - o cli.byte
it I get the following error:
File "cli.ml", line 2, characters 0-13:
Error: Unbound module Lwt_term
I know it's unrelated to the problem above, but from utop I can open Lwt but I still can't open Lwt_term. What am I doing wrong?
Source file is located there so I bet that you need lwt.text package
Not really a real answer to the original question, but I have ended up using Core to accomplish it. The enlightenment came from finding the readline_test.ml file in a tests folder in the Core library (https://github.com/janestreet/core_extended/blob/master/lib_test/readline_test.ml).
Following that example it was really easy to implement readline-like functionality.

emacs flycheck syntax checher for cpp file

I am using Emacs 24.3.1 to edit a .cpp file and when I activate M-x flycheck-mode, it shows the state being (C++/l FlyC- Abbrev), where FlyC- means it did not find a suitable syntax checker.
I can't see anything looking like a C++ checher in the list I get from flycheck-select-checker:
Possible completions are:
bash coffee-coffeelint css-csslint
emacs-lisp emacs-lisp-checkdoc go-build
go-gofmt go-test haml
html-tidy javascript-jshint json-jsonlint
lua perl php
php-phpcs python-flake8 python-pyflakes
python-pylint rst ruby
rust-rustc sass scss
sh tex-chktex tex-lacheck
xml-xmlstarlet zsh
Any ideas what might be missing?
I have both c/c++-clang and c/c++-cppcheck when I run flycheck-select-checker. Perhaps you're using an out of date flycheck?

clang_complete vim extension not working with STL

I have installed clang and clang_complete on a Linux system.
I added the following lines to my .vimrc:
let g:clang_user_options='|| exit 0'
set completeopt-=preview
Auto-completion works for my own code. However, it doesn't work with STL container. Even when I just type std::, I see a "user defined completion - pattern not found" at the bottom of the screen. What is the problem?
I use Vim 7.3 and clang_complete 1.8
The workaround is to tell clang_complete to use the clang library (instead of binary) for parsing. This is done by adding the following line to .vimrc:
let g:clang_use_library=1

Error: Unbound value Ppl.manager_alloc_strict

I just installed a package called Ppl, here is the result of find -name "*ppl.*" under /usr/:
./lib/libppl.so.7.1.0
./lib/libppl.so.7
./lib/libcloog-ppl.so.0
./local/share/man/man3/libppl.3
./local/share/aclocal/ppl.m4
./local/include/ppl.hh
./local/lib/libppl.so
./local/lib/libppl.la
./local/lib/libppl.a
./local/lib/libppl.so.9
./local/lib/libppl.so.9.0.0
But when I run the following code by ocamlc -I /usr/local/lib/ocaml/3.11.2/apron -I /usr/local/lib/ocaml/3.11.2/gmp/ -I /usr/local/lib/ -c file.ml, I got an error Unbound value Ppl.manager_alloc_strict.
open Apron;;
open Mpqf;;
open Format;;
let print_array = Abstract0.print_array;;
let lincons1_array_print fmt x =
Lincons1.array_print fmt x
;;
let generator1_array_print fmt x =
Generator1.array_print fmt x
;;
let manpk = Polka.manager_alloc_strict();;
let manbox = Box.manager_alloc ();;
let manoct = Oct.manager_alloc ();;
let manppl = Ppl.manager_alloc_strict();;
...
Does anyone know what happened? Thank you very much!
You've showed us the library, but not anything regarding the OCaml interface to the library -- cmx or cmxa for native compilation. Just as the comment I left prior, do the same thing with where Ppl package for OCaml is. OCaml is not interfacing with the C library directly (.a, .so), but through a compiled interface (cmxa or cmi files).
You might also consider using the ocamlbuild system. You can tag modules with external dependencies, and have the build system find the package (via ocamlfind, or hard-coded).