#ifndef FISH_OPERATION_CONTEXT_H #define FISH_OPERATION_CONTEXT_H #include #include "common.h" class environment_t; class parser_t; class job_group_t; /// A common helper which always returns false. bool no_cancel(); /// A operation_context_t is a simple property bag which wraps up data needed for highlighting, /// expansion, completion, and more. /// It contains the following triple: /// 1. A parser. This is often null. If not null, it may be used to execute fish script. If null, /// then this is a background operation and fish script must not be executed. /// 2. A variable set. This is never null. This may differ from the variables in the parser. /// 3. A cancellation checker. This is a function which you may call to detect that the operation /// is no longer necessary and should be cancelled. class operation_context_t { public: // The parser, if this is a foreground operation. If this is a background operation, this may be // nullptr. std::shared_ptr parser; // The set of variables. It is the creator's responsibility to ensure this lives as log as the // context itself. const environment_t &vars; /// The job group of the parental job. /// This is used only when expanding command substitutions. If this is set, any jobs created by /// the command substitions should use this tree. std::shared_ptr job_group{}; // A function which may be used to poll for cancellation. cancel_checker_t cancel_checker; // Invoke the cancel checker. \return if we should cancel. bool check_cancel() const { return cancel_checker(); } // \return an "empty" context which contains no variables, no parser, and never cancels. static operation_context_t empty(); // \return an operation context that contains only global variables, no parser, and never // cancels. static operation_context_t globals(); /// Construct from the full triple of a parser, vars, and cancel checker. operation_context_t(std::shared_ptr parser, const environment_t &vars, cancel_checker_t cancel_checker); /// Construct from vars alone. explicit operation_context_t(const environment_t &vars) : operation_context_t(nullptr, vars, no_cancel) {} ~operation_context_t(); }; #endif