This package contains the implementation of a universal REPL (Read-Eval-Print-Loop) which can be used on top of a Curry compiler. Thus, if the Curry compiler supports some standard options (see below), it can be extended to a simple interactive programming environment.
The specification of the concrete compiler is provided as an element of type
REPL.Compiler.CCDescription. The entry point of the REPL is the operation
mainREPL defined in module
REPL.Main. The directory
examples contains example specifications.
Basically, the REPL translates each expression to be evaluated into a program with a
main operation. This program is compiled and then executed. In order to implement this kind of REPL, it should be possible to invoke the Curry compiler
cc as follows:
cc [-vn] [-iDIR] ... [-iDIR] [--parse-options="PO"] [-c|--compile] MOD
-vn: verbosity with 0<=n<=4
DIRto search for imported modules
-c: compile only
PO: options passed to the Curry front end
MOD: the module to be compiled containing an operation
This command should compile module
MOD (and, if necessary, all imported modules) and create an executable
MOD which executes the operation
main in this module.
MOD might be a hierarchical module name, e.g.,
Dir.Mod. In this case, the executable
Dir.Mod is generated where the source code of the module is stored in
If the option
--compile is provided, the executable is not generated. This might be reasonable to compile all modules in order to check for errors and speed up later compilations without re-compiling all imports.
If the module name is prefixed by a path, e.g.,
dir1/dir2/Mod, then we change into the directory of the path (
dir1/dir2) and compile the main module there.
Options beyond this general usage might depend on the compiler. For instance, each compiler might implement a different set of search strategies. Here are some examples of options and their values:
The actual options are specified by data of type
CCOption (see module
In order to use a Curry compiler together with CPM, it has to support some options so that CPM can interact with the compiler. The Curry REPL implements these options provided that the Curry compiler itself provides options about its version. If
cc is the executable of the compiler, the following options must exist:
cc --compiler-name: Shows that name of the compiler (which occurs in compiler dependencies of package specifications) and quits.
cc --numeric-version: Shows the compiler version quits.
cc --base-version: Shows the version of the base libraries implemented by the compiler and quits.
These options can also be combined. In this case the information is shown in subsequent lines, as shown in this example for PAKCS:
> pakcs --compiler-name --numeric-version --base-version pakcs 3.3.0 3.0.0
The intermediate files produced by the compiler should be stored in the directory
relative to the directory of the source file. If the source file is a hierarchical module, the same hierarchy is used relative to
When CPM starts a Curry system (via
cypm curry), it sets the environment variable
CURRYPATH to the load path of all included packages and passes the option
--nocypm to the executable of the Curry system. Usually, when a Curry system is started, it should query CPM (by
cypm deps -p) to get the value of
CURRYPATH to load modules. The option
--nocypm is intended to turn off this behavior.
If CPM installs an executable, it passes the following options (REPL commands) to the compiler:
> cc :set v0 :load MAINMOD :save :quit
v0 is replaced by
v1 in debug mode). The execution of this command should install the executable