CIDER:

The Curry Integrated Development EnviRonment

(Version of August 9, 2004)

• a program editor with the usual functionality,
• various tools for analyzing properties of functions in Curry programs (types, overlapping definitions, complete definitions, non-determinism, operational completeness, dependencies etc),
• a tool for drawing dependency graphs,
• a graphical debugger, i.e., a visualization of the evaluation of expressions.

To get an impression of the use of CIDER, here is the main window after starting CIDER and loading a program:

The main window in the middle is an editor window for editing the current program. On the left- and right-hand side, there is a list of the top-level functions in the current file and a list of the currently available analysis tools, respectively. After selecting a function and an analysis in the corresponding list boxes, the function is analyzed and the analysis result is either shown in the bottom window (if it is a textual result) or, if it is a graph, it is visualized with the graph visualization tool daVinci. Currently, CIDER offers the following analysis tools (which are useful but not very complex and mainly included for demonstration issues):

• Get Type: Compute the function's type.
• Overlapping Rules: Is the function defined by overlapping rules that might cause non-deterministic evaluations even for ground expressions?
• Pattern Complete: Is the function completely defined, i.e., reducible on all ground constructor terms?
• Pattern Matching: Shows the pattern matching behavior, i.e., a definition of the function in form of case expressions.
• Solution Complete: Is the function able to compute all solutions? (This is the case if this and all functions used in derivations are flexible.)
• Set-Valued: Does the function might have more than one result to a ground call (due to a non-deterministic definition)?
• Indeterminism: Does the function behave indeterministically, i.e., has a time-dependent behavior (e.g., due to the use of external communication)?
• Depends on: Call dependency, i.e., all functions that might be called during the evaluation of a call to this function.
• Dependency Graph: Show the dependency graph for this function.
• Called By: Compute the list of all functions that call this function in their defining rules.
• Dead Code: Compute the list of all top-level functions that are not reachable from this function.

Finally, CIDER contains also a graphical debugger/tracer to visualize the evaluation of expressions. Currently, the debugger always starts with the evaluation of the expression "main" w.r.t. the currently loaded program, i.e., if one wants to visualize the evaluation of an expression e, one has to add the definition "main = e" to the current program. The debugger always shows the expressions as trees although some parts of the expressions are actually shared. If a shared subexpression is reduced, all shared identical subexpressions are also reduced in the same step in order to be conform with Curry's operational semantics. The subexpression reduced in the next step (the next redex) is always emphasized in red (similarly, a variable is emphasized in red if it will be bound in the next step). One can trace forward and backward through all evaluation steps. Furthermore, one can also set a breakpoint to skip larger parts of a computation. However, the evaluator used by the debugger is not very fast since it is based on a meta-evaluator for Curry programs implemented in Curry. A snapshot of the debugger is shown in the following picture:

Implementation

Requirements for installing CIDER: Since CIDER is implemented in Curry, it requires an installed Curry system. The implementation uses various system libraries (for distributed programming, GUI programming, etc) which are available in the PAKCS distribution. Thus, you should have PAKCS (Version 1.6) installed in order to compile CIDER. Since the implementation is mainly based on the Tk library of PAKCS, you need also a Tcl/Tk implementation (including the windowing shell wish) which can be downloaded here. If you want to use the graph visualization tool, you need also an installed daVinci system which can be downloaded here.

Short overview of CIDER

This short description of a system demonstration of CIDER provides an introduction into the main functionality of CIDER.

An Integrated Development Environment for Declarative Multi-Paradigm Programming

This paper describes the functionality of CIDER and the main ideas behind the implementation of CIDER. It also contains a short description how to extend the functionality of CIDER (e.g., adding new program analyses).

Diploma thesis (in German)

This is a diploma thesis on CIDER, written by Johannes Koj (the main implementor of CIDER). This thesis contains details about the design and implementation of CIDER.