Instruction file imported from OzCog/opencog-unified (.github/instructions/opencog-cpp.instructions.md). Copyright stays with the author.

--- description: 'OpenCog C++ coding standards and patterns. Stacks with cmake-vcpkg and cpp-language-service-tools instructions.' applyTo: '**/.cc, **/.cpp, **/.h, **/.hpp, **/*.cxx'

OpenCog C++ Coding Standards

Naming Conventions

• Classes: CamelCase (e.g., AtomSpace, TruthValue, HandleSeq)
• Functions: snake_case (e.g., get_handle, add_atom)
• Member variables: _underscore_prefix (e.g., _atomspace, _name)
• Constants: ALL_CAPS (e.g., MAX_ARITY, DEFAULT_TV)
• Namespaces: opencog (always)

Include Guards

#ifndef _OPENCOG_COMPONENT_CLASS_H
#define _OPENCOG_COMPONENT_CLASS_H
// ...
#endif // _OPENCOG_COMPONENT_CLASS_H

Common Types

using namespace opencog;

Handle h;                    // Atom reference
HandleSeq hs;               // std::vector<Handle>
HandleSet hset;             // std::unordered_set<Handle>
AtomSpace* as;              // AtomSpace pointer
TruthValuePtr tv;           // shared_ptr<TruthValue>
ValuePtr vp;                // shared_ptr<Value>
Type t;                     // Atom type ID

Factory Functions (prefer over constructors)

Handle h = as->add_node(CONCEPT_NODE, "name");
Handle l = as->add_link(INHERITANCE_LINK, {h1, h2});
TruthValuePtr tv = createSimpleTruthValue(0.9, 0.8);

Error Handling

• Use OC_ASSERT(condition, "message") from cogutil
• Throw InvalidParamException for bad inputs
• Throw RuntimeException for unexpected states
• Never silently swallow exceptions

Build Integration

• Every .cc file must be listed in component's CMakeLists.txt
• Headers go in opencog/component-name/
• Implementation goes alongside headers or in src/
• Tests in tests/component-name/