+ # Keeps the frame count in memory to find when to stop
+ # and launch the command prompt after a step out call
+ var step_stack_count = 1
+
+ # Triggers a step over an instruction in a nit program
+ var stop_after_step_over_trigger = true
+
+ # Triggers a step out of an instruction
+ var stop_after_step_out_trigger= false
+
+ # Triggers a step in a instruction (enters a function
+ # if the instruction is a function call)
+ var step_in_trigger = false
+
+ # HashMap containing the breakpoints bound to a file
+ var breakpoints = new HashMap[String, HashSet[Breakpoint]]
+
+ # Contains the current file
+ var curr_file = ""
+
+ # Aliases hashmap (maps an alias to a variable name)
+ var aliases = new HashMap[String, String]
+
+ # Set containing all the traced variables and their related frame
+ private var traces = new HashSet[TraceObject]
+
+ # Map containing all the positions for the positions of the arguments traced
+ # In a function call
+ private var fun_call_arguments_positions = new HashMap[Int, TraceObject]
+
+ # Triggers the remapping of a trace object in the local context after a function call
+ var aftermath = false
+
+ # Used to prevent the case when the body of the function called is empty
+ # If it is not, then, the remapping won't be happening
+ var frame_count_aftermath = 1
+
+ # Auto continues the execution until the end or until an error is encountered
+ var autocontinue = false
+
+ #######################################################################
+ ## Execution of statement function ##
+ #######################################################################
+
+ # Main loop, every call to a debug command is done here
+ redef fun stmt(n: nullable AExpr)
+ do
+ if n == null then return
+
+ var frame = self.frame
+ var old = frame.current_node
+ frame.current_node = n
+
+ if not self.autocontinue then
+ if not n isa ABlockExpr then
+ steps_fun_call(n)
+
+ breakpoint_check(n)
+
+ check_funcall_and_traced_args(n)
+
+ remap(n)
+
+ check_if_vars_are_traced(n)
+ end
+ end
+
+ n.stmt(self)
+ frame.current_node = old
+ end
+
+ # Does the same as an usual send, except it will modify the call chain on the first call when injecting code at Runtime using the debugger.
+ # Instead of creating a pristine Frame, it will copy the actual values of the frame, and re-inject them after execution in the current context.
+ fun rt_send(mproperty: MMethod, args: Array[Instance]): nullable Instance
+ do
+ var recv = args.first
+ var mtype = recv.mtype
+ var ret = send_commons(mproperty, args, mtype)
+ if ret != null then return ret
+ var propdef = mproperty.lookup_first_definition(self.mainmodule, mtype)
+ return self.rt_call(propdef, args)
+ end
+
+ # Same as a regular call but for a runtime injected module
+ #
+ fun rt_call(mpropdef: MMethodDef, args: Array[Instance]): nullable Instance
+ do
+ args = call_commons(mpropdef, args)
+ return rt_call_without_varargs(mpropdef, args)
+ end
+
+ # Common code to call and this function
+ #
+ # Call only executes the variadic part, this avoids
+ # double encapsulation of variadic parameters into an Array
+ fun rt_call_without_varargs(mpropdef: MMethodDef, args: Array[Instance]): nullable Instance
+ do
+ if self.modelbuilder.toolcontext.opt_discover_call_trace.value and not self.discover_call_trace.has(mpropdef) then
+ self.discover_call_trace.add mpropdef
+ self.debug("Discovered {mpropdef}")
+ end
+ assert args.length == mpropdef.msignature.arity + 1 else debug("Invalid arity for {mpropdef}. {args.length} arguments given.")
+
+ # Look for the AST node that implements the property
+ var mproperty = mpropdef.mproperty
+ if self.modelbuilder.mpropdef2npropdef.has_key(mpropdef) then
+ var npropdef = self.modelbuilder.mpropdef2npropdef[mpropdef]
+ self.parameter_check(npropdef, mpropdef, args)
+ if npropdef isa AConcreteMethPropdef then
+ return npropdef.rt_call(self, mpropdef, args)
+ else
+ print "Error, invalid propdef to call at runtime !"
+ return null
+ end
+ else if mproperty.name == "init" then
+ var nclassdef = self.modelbuilder.mclassdef2nclassdef[mpropdef.mclassdef]
+ self.parameter_check(nclassdef, mpropdef, args)
+ return nclassdef.call(self, mpropdef, args)
+ else
+ fatal("Fatal Error: method {mpropdef} not found in the AST")
+ abort
+ end
+ end
+
+ # Evaluates dynamically a snippet of Nit code
+ # `nit_code` : Nit code to be executed
+ fun eval(nit_code: String)
+ do
+ var local_toolctx = modelbuilder.toolcontext
+ local_toolctx.dbg = self
+ var e = local_toolctx.parse_something(nit_code)
+ if e isa AExpr then
+ nit_code = "print " + nit_code
+ e = local_toolctx.parse_something(nit_code)
+ end
+ if e isa AModule then
+ local_toolctx.had_error = false
+ modelbuilder.load_rt_module(self.mainmodule, e, "rt_module")
+ local_toolctx.run_phases([e])
+ if local_toolctx.had_error then
+ modelbuilder.model.try_remove_module(e.mmodule.as(not null))
+ local_toolctx.dbg = null
+ return
+ end
+ var mmod = e.mmodule
+ if mmod != null then
+ self.mainmodule = mmod
+ var local_classdefs = mmod.mclassdefs
+ var sys_type = mmod.sys_type
+ if sys_type == null then
+ print "Fatal error, cannot find Class Sys !\nAborting"
+ abort
+ end
+ var mobj = new MutableInstance(sys_type)
+ init_instance(mobj)
+ var initprop = mmod.try_get_primitive_method("init", sys_type.mclass)
+ if initprop != null then
+ self.send(initprop, [mobj])
+ end
+ var mainprop = mmod.try_get_primitive_method("main", sys_type.mclass)
+ if mainprop != null then
+ self.rt_send(mainprop, [mobj])
+ end
+ else
+ print "Error while loading_rt_module"
+ end
+ else
+ print "Error when parsing, e = {e.class_name}"
+ end
+ local_toolctx.dbg = null
+ end
+
+ # Encpasulates the behaviour for step over/out
+ private fun steps_fun_call(n: AExpr)
+ do
+ if self.stop_after_step_over_trigger then
+ if self.frames.length <= self.step_stack_count then
+ n.debug("Execute stmt {n.to_s}")
+ while read_cmd do end
+ end
+ else if self.stop_after_step_out_trigger then
+ if frames.length < self.step_stack_count then
+ n.debug("Execute stmt {n.to_s}")
+ while read_cmd do end
+ end
+ else if step_in_trigger then
+ n.debug("Execute stmt {n.to_s}")
+ while read_cmd do end
+ end
+ end
+
+ # Checks if a breakpoint is encountered, and launches the debugging prompt if true
+ private fun breakpoint_check(n: AExpr)
+ do
+ var currFileNameSplit = self.frame.current_node.location.file.filename.to_s.split_with("/")
+
+ self.curr_file = currFileNameSplit[currFileNameSplit.length-1]
+
+ var breakpoint = find_breakpoint(curr_file, n.location.line_start)
+
+ if breakpoints.keys.has(curr_file) and breakpoint != null then
+
+ breakpoint.check_in
+
+ if not breakpoint.is_valid
+ then
+ remove_breakpoint(curr_file, n.location.line_start)
+ end
+
+ n.debug("Execute stmt {n.to_s}")
+ while read_cmd do end
+ end
+ end
+
+ # Check if a variable of current expression is traced
+ # Then prints and/or breaks for command prompt
+ private fun check_if_vars_are_traced(n: AExpr)
+ do
+ var identifiers_in_instruction = get_identifiers_in_current_instruction(n.location.text)
+
+ for i in identifiers_in_instruction do
+ var variable = seek_variable(i, frame)
+ for j in self.traces do
+ if j.is_variable_traced_in_frame(i, frame) then
+ n.debug("Traced variable {i} used")
+ if j.break_on_encounter then while read_cmd do end
+ break
+ end
+ end
+ end
+ end
+
+ # Function remapping all the traced objects to match their name in the local context
+ private fun remap(n: AExpr)
+ do
+ if self.aftermath then
+
+ # Trace every argument variable pre-specified
+ if self.frame_count_aftermath < frames.length and fun_call_arguments_positions.length > 0 then
+
+ var ids_in_fun_def = get_identifiers_in_current_instruction(get_function_arguments(frame.mpropdef.location.text))
+
+ for i in fun_call_arguments_positions.keys do
+ self.fun_call_arguments_positions[i].add_frame_variable(frame, ids_in_fun_def[i])
+ end
+ end
+
+ self.aftermath = false
+ end
+ end
+
+ # If the current instruction is a function call
+ # We analyse its signature and the position of traced arguments if the call
+ # For future remapping when inside the function
+ private fun check_funcall_and_traced_args(n: AExpr) do
+ # If we have a function call, we need to see if any of the arguments is traced (including the caller)
+ # if it is, next time we face an instruction, we'll trace the local version on the traced variable in the next frame
+ if n isa ACallExpr then
+ self.aftermath = true
+ self.frame_count_aftermath = frames.length
+ fun_call_arguments_positions.clear
+ var fun_arguments = get_identifiers_in_current_instruction(get_function_arguments(n.location.text))
+
+ for i in self.traces do
+ for j in [0 .. fun_arguments.length - 1] do
+ if i.is_variable_traced_in_frame(fun_arguments[j],frame) then
+ fun_call_arguments_positions[j] = i
+ end
+ end
+ end
+ end
+ end
+
+ #######################################################################
+ ## Processing commands functions ##
+ #######################################################################
+
+ fun read_cmd: Bool
+ do
+ printn "> "
+ return process_debug_command(gets)
+ end
+
+ # Takes a user command as a parameter
+ #
+ # Returns a boolean value, representing whether or not to
+ # continue reading commands from the console input
+ fun process_debug_command(command:String): Bool
+ do
+ # Step-out command
+ if command == "finish"
+ then
+ return step_out
+ # Step-in command
+ else if command == "s"
+ then
+ return step_in
+ # Step-over command
+ else if command == "n" then
+ return step_over
+ # Opens a new NitIndex prompt on current model
+ else if command == "nitx" then
+ new NitIndex.with_infos(modelbuilder, self.mainmodule).prompt
+ return true
+ # Continues execution until the end
+ else if command == "c" then
+ return continue_exec
+ else if command == "nit" then
+ printn "$~> "
+ command = gets
+ var nit_buf = new Buffer
+ while not command == ":q" do
+ nit_buf.append(command)
+ nit_buf.append("\n")
+ printn "$~> "
+ command = gets
+ end
+ step_in
+ eval(nit_buf.to_s)
+ else if command == "quit" then
+ exit(0)
+ else if command == "abort" then
+ print stack_trace
+ exit(0)
+ else
+ var parts_of_command = command.split_with(' ')
+ # Shows the value of a variable in the current frame
+ if parts_of_command[0] == "p" or parts_of_command[0] == "print" then
+ print_command(parts_of_command)
+ # Places a breakpoint on line x of file y
+ else if parts_of_command[0] == "break" or parts_of_command[0] == "b"
+ then
+ process_place_break_fun(parts_of_command)
+ # Places a temporary breakpoint on line x of file y
+ else if parts_of_command[0] == "tbreak" and (parts_of_command.length == 2 or parts_of_command.length == 3)
+ then
+ process_place_tbreak_fun(parts_of_command)
+ # Removes a breakpoint on line x of file y
+ else if parts_of_command[0] == "d" or parts_of_command[0] == "delete" then
+ process_remove_break_fun(parts_of_command)
+ # Sets an alias for a variable
+ else if parts_of_command.length == 3 and parts_of_command[1] == "as"
+ then
+ add_alias(parts_of_command[0], parts_of_command[2])
+ # Modifies the value of a variable in the current frame
+ else if parts_of_command.length >= 3 and parts_of_command[1] == "=" then
+ process_mod_function(parts_of_command)
+ # Traces the modifications on a variable
+ else if parts_of_command.length >= 2 and parts_of_command[0] == "trace" then
+ process_trace_command(parts_of_command)
+ # Untraces the modifications on a variable
+ else if parts_of_command.length == 2 and parts_of_command[0] == "untrace" then
+ process_untrace_command(parts_of_command)
+ else
+ print "Unknown command \"{command}\""
+ end
+ end
+ return true
+ end
+
+ #######################################################################
+ ## Processing specific command functions ##
+ #######################################################################
+
+ # Sets the flags to step-over an instruction in the current file
+ fun step_over: Bool
+ do
+ self.step_stack_count = frames.length
+ self.stop_after_step_over_trigger = true
+ self.stop_after_step_out_trigger = false
+ self.step_in_trigger = false
+ return false
+ end
+
+ #Sets the flags to step-out of a function
+ fun step_out: Bool
+ do
+ self.stop_after_step_over_trigger = false
+ self.stop_after_step_out_trigger = true
+ self.step_in_trigger = false
+ self.step_stack_count = frames.length
+ return false
+ end
+
+ # Sets the flags to step-in an instruction
+ fun step_in: Bool
+ do
+ self.step_in_trigger = true
+ self.stop_after_step_over_trigger = false
+ self.stop_after_step_out_trigger = false
+ return false
+ end
+
+ # Sets the flags to continue execution
+ fun continue_exec: Bool
+ do
+ self.stop_after_step_over_trigger = false
+ self.stop_after_step_out_trigger = false
+ self.step_in_trigger = false
+ return false
+ end
+
+ # Prints the demanded variable in the command
+ #
+ # The name of the variable in in position 1 of the array 'parts_of_command'
+ fun print_command(parts_of_command: Array[String])
+ do
+ if parts_of_command[1] == "*" then
+ var map_of_instances = frame.map
+
+ var keys = map_of_instances.iterator
+
+ print "Variables collection : \n"
+
+ for instance in map_of_instances.keys do
+ print "Variable {instance.to_s}, Instance {map_of_instances[instance].to_s}"
+ end
+
+ print "\nEnd of current instruction \n"
+ else if parts_of_command[1] == "stack" then
+ print self.stack_trace
+ else if parts_of_command[1].chars.has('[') and parts_of_command[1].chars.has(']') then
+ process_array_command(parts_of_command)
+ else
+ var instance = seek_variable(get_real_variable_name(parts_of_command[1]), frame)
+
+ if instance != null
+ then
+ print_instance(instance)
+ else
+ print "Cannot find variable {parts_of_command[1]}"
+ end
+ end
+ end
+
+ # Processes the input string to know where to put a breakpoint
+ fun process_place_break_fun(parts_of_command: Array[String])
+ do
+ var bp = get_breakpoint_from_command(parts_of_command)
+ if bp != null then
+ place_breakpoint(bp)
+ end
+ end
+
+ # Returns a breakpoint containing the informations stored in the command
+ fun get_breakpoint_from_command(parts_of_command: Array[String]): nullable Breakpoint
+ do
+ if parts_of_command[1].is_numeric then
+ return new Breakpoint(parts_of_command[1].to_i, curr_file)
+ else if parts_of_command.length >= 3 and parts_of_command[2].is_numeric then
+ return new Breakpoint(parts_of_command[2].to_i, parts_of_command[1])
+ else
+ return null
+ end
+ end
+
+ # Processes the command of removing a breakpoint on specified line and file
+ fun process_remove_break_fun(parts_of_command: Array[String])
+ do
+ if parts_of_command[1].is_numeric then
+ remove_breakpoint(self.curr_file, parts_of_command[1].to_i)
+ else if parts_of_command.length >= 3 and parts_of_command[2].is_numeric then
+ remove_breakpoint(parts_of_command[1], parts_of_command[2].to_i)
+ end
+ end
+
+ # Processes an array print command
+ fun process_array_command(parts_of_command: Array[String])
+ do
+ var index_of_first_brace = parts_of_command[1].index_of('[')
+ var variable_name = get_real_variable_name(parts_of_command[1].substring(0,index_of_first_brace))
+ var braces = parts_of_command[1].substring_from(index_of_first_brace)
+
+ var indexes = remove_braces(braces)
+
+ var index_array = new Array[Array[Int]]
+
+ if indexes != null then
+ for index in indexes do
+ var temp_indexes_array = process_index(index)
+ if temp_indexes_array != null then
+ index_array.push(temp_indexes_array)
+ #print index_array.last
+ end
+ end
+ end
+
+ var instance = seek_variable(variable_name, frame)
+
+ if instance != null then
+ print_nested_collection(instance, index_array, 0, variable_name, "")
+ else
+ print "Cannot find variable {variable_name}"
+ end
+ end
+
+ # Processes the modification function to modify a variable dynamically
+ #
+ # Command of type variable = value
+ fun process_mod_function(parts_of_command: Array[String])
+ do
+ parts_of_command[0] = get_real_variable_name(parts_of_command[0])
+ var parts_of_variable = parts_of_command[0].split_with(".")
+
+ if parts_of_variable.length > 1 then
+ var last_part = parts_of_variable.pop
+ var first_part = parts_of_command[0].substring(0,parts_of_command[0].length - last_part.length - 1)
+ var papa = seek_variable(first_part, frame)
+
+ if papa != null and papa isa MutableInstance then
+ var attribute = get_attribute_in_mutable_instance(papa, last_part)
+
+ if attribute != null then
+ modify_argument_of_complex_type(papa, attribute, parts_of_command[2])
+ end
+ end
+ else
+ var target = seek_variable(parts_of_variable[0], frame)
+ if target != null then
+ modify_in_frame(target, parts_of_command[2])
+ end
+ end
+ end
+
+ # Processes the untrace variable command
+ #
+ # Command pattern : "untrace variable"
+ fun process_untrace_command(parts_of_command: Array[String])
+ do
+ var variable_name = get_real_variable_name(parts_of_command[1])
+ if untrace_variable(variable_name) then
+ print "Untraced variable {parts_of_command[1]}"
+ else
+ print "{parts_of_command[1]} is not traced"
+ end
+ end
+
+ # Processes the trace variable command
+ #
+ # Command pattern : "trace variable [break/print]"
+ fun process_trace_command(parts_of_command: Array[String])
+ do
+ var variable_name = get_real_variable_name(parts_of_command[1])
+ var breaker:Bool
+
+ if seek_variable(variable_name, frame) == null then
+ print "Cannot find a variable called {parts_of_command[1]}"
+ return
+ end
+
+ if parts_of_command.length == 3 then
+ if parts_of_command[2] == "break" then
+ breaker = true
+ else
+ breaker = false
+ end
+ else
+ breaker = false
+ end
+
+ trace_variable(variable_name, breaker)
+
+ print "Successfully tracing {parts_of_command[1]}"
+ end
+
+ #######################################################################
+ ## Trace Management functions ##
+ #######################################################################
+
+ # Effectively untraces the variable called *variable_name*
+ #
+ # Returns true if the variable exists, false otherwise
+ private fun untrace_variable(variable_name: String): Bool
+ do
+ var to_remove: nullable TraceObject = null
+ for i in self.traces do
+ if i.is_variable_traced_in_frame(variable_name, frame) then
+ to_remove = i
+ end
+ end
+
+ if to_remove != null then
+ self.traces.remove(to_remove)
+ return true
+ else
+ return false
+ end
+ end
+
+ # Effectively traces the variable *variable_name* either in print or break mode depending on the value of breaker (break if true, print if false)
+ #
+ private fun trace_variable(variable_name: String, breaker: Bool)
+ do
+ for i in self.traces do
+ if i.is_variable_traced_in_frame(variable_name, frame) then
+ print "This variable is already traced"
+ return
+ end
+ end
+
+ var trace_object: TraceObject
+
+ if breaker then
+ trace_object = new TraceObject(true)
+ else
+ trace_object = new TraceObject(false)
+ end
+
+ # We trace the current variable found for the current frame
+ trace_object.add_frame_variable(self.frame, variable_name)
+
+ var position_of_variable_in_arguments = get_position_of_variable_in_arguments(frame, variable_name)
+
+ # Start parsing the frames starting with the parent of the current one, until the highest
+ # When the variable traced is declared locally, the loop stops
+ for i in [1 .. frames.length-1] do
+
+ # If the variable was reported to be an argument of the previous frame
+ if position_of_variable_in_arguments != -1 then
+
+ var local_name = get_identifiers_in_current_instruction(get_function_arguments(frames[i].current_node.location.text))[position_of_variable_in_arguments]
+
+ position_of_variable_in_arguments = get_position_of_variable_in_arguments(frames[i], local_name)
+
+ trace_object.add_frame_variable(frames[i], local_name)
+ else
+ break
+ end
+ end
+
+ self.traces.add(trace_object)
+ end
+
+ # If the variable *variable_name* is an argument of the function being executed in the frame *frame*
+ # The function returns its position in the arguments
+ # Else, it returns -1
+ private fun get_position_of_variable_in_arguments(frame: Frame, variable_name: String): Int
+ do
+ var identifiers = get_identifiers_in_current_instruction(get_function_arguments(frame.mpropdef.location.text))
+ for i in [0 .. identifiers.length-1] do
+ # If the current traced variable is an argument of the current function, we trace its parent (at least)
+ if identifiers[i] == variable_name then return i
+ end
+ return -1
+ end
+
+ # Gets all the identifiers of an instruction (uses the rules of Nit as of Mar 05 2013)
+ #
+ fun get_identifiers_in_current_instruction(instruction: AbstractString): Array[String]
+ do
+ var result_array = new Array[String]
+ var instruction_buffer = new Buffer
+
+ var trigger_char_escape = false
+ var trigger_string_escape = false
+ var trigger_concat_in_string = false
+
+ for i in instruction.chars do
+ if trigger_char_escape then
+ if i == '\'' then trigger_char_escape = false
+ else if trigger_string_escape then
+ if i == '{' then
+ trigger_concat_in_string = true
+ trigger_string_escape = false
+ else if i == '\"' then trigger_string_escape = false
+ else
+ if i.is_alphanumeric or i == '_' then
+ instruction_buffer.add(i)
+ else if i == '.' then
+ if instruction_buffer.is_numeric or (instruction_buffer.chars[0] >= 'A' and instruction_buffer.chars[0] <= 'Z') then
+ instruction_buffer.clear
+ else
+ result_array.push(instruction_buffer.to_s)
+ instruction_buffer.add(i)
+ end
+ else if i == '\'' then
+ trigger_char_escape = true
+ else if i == '\"' then
+ trigger_string_escape = true
+ else if i == '}' then
+ trigger_concat_in_string = false
+ trigger_string_escape = true
+ else
+ if instruction_buffer.length > 0 and not instruction_buffer.is_numeric and not (instruction_buffer.chars[0] >= 'A' and instruction_buffer.chars[0] <= 'Z') then result_array.push(instruction_buffer.to_s)
+ instruction_buffer.clear
+ end
+ end
+ end
+
+ if instruction_buffer.length > 0 and not instruction_buffer.is_numeric and not (instruction_buffer.chars[0] >= 'A' and instruction_buffer.chars[0] <= 'Z') then result_array.push(instruction_buffer.to_s)
+
+ return result_array
+ end
+
+ # Takes a function call or declaration and strips all but the arguments
+ #
+ fun get_function_arguments(function: AbstractString): String
+ do
+ var buf = new Buffer
+ var trigger_copy = false
+
+ for i in function.chars do
+ if i == ')' then break
+ if trigger_copy then buf.add(i)
+ if i == '(' then trigger_copy = true
+ end
+
+ return buf.to_s
+ end
+
+ #######################################################################
+ ## Alias management functions ##
+ #######################################################################
+
+ # Adds a new alias to the tables
+ fun add_alias(var_represented: String, alias: String)
+ do
+ self.aliases[alias] = var_represented
+ end
+
+ # Gets the real name of a variable hidden by an alias
+ fun get_variable_name_by_alias(alias: String): nullable String
+ do
+ if self.aliases.keys.has(alias) then
+ return self.aliases[alias]
+ end
+
+ return null
+ end
+
+ # Gets the variable named by name, whether it is an alias or not
+ fun get_real_variable_name(name: String): String
+ do
+ var explode_string = name.split_with(".")
+ var final_string = new Buffer
+ for i in explode_string do
+ var alias_resolved = get_variable_name_by_alias(i)
+ if alias_resolved != null then
+ final_string.append(get_real_variable_name(alias_resolved))
+ else
+ final_string.append(i)
+ end
+ final_string.append(".")
+ end
+
+ return final_string.substring(0,final_string.length-1).to_s
+ end
+
+ #######################################################################
+ ## Print functions ##
+ #######################################################################
+
+ # Prints an object instance and its attributes if it has some
+ #
+ # If it is a primitive type, its value is directly printed
+ fun print_instance(instance: Instance)
+ do
+ print "Printing innards of a variable"
+
+ if instance isa MutableInstance then
+ var attributes = instance.attributes
+ print "Object : {instance}"
+
+ for current_attribute in attributes.keys do
+ print "Attribute : {current_attribute.to_s} \nValeur : {attributes[current_attribute].to_s}"
+ end
+ else
+ print "Found variable {instance}"
+ end
+
+ print "Stopping printing innards of a variable"
+ end
+
+ # Prints the attributes demanded in a SequenceRead
+ # Used recursively to print nested collections
+ fun print_nested_collection(instance: Instance, indexes: Array[Array[Int]], depth: Int, variable_name: String, depth_string: String)
+ do
+ var collection: nullable SequenceRead[Object] = null
+ var real_collection_length: nullable Int = null
+
+ if instance isa MutableInstance then
+ real_collection_length = get_collection_instance_real_length(instance)
+ collection = get_primary_collection(instance)
+ end
+
+ if collection != null and real_collection_length != null then
+ for i in indexes[depth] do
+ if i >= 0 and i < real_collection_length then
+ if depth == indexes.length-1 then
+ print "{variable_name}{depth_string}[{i}] = {collection[i]}"
+ else
+ var item_i = collection[i]
+
+ if item_i isa MutableInstance then
+ print_nested_collection(item_i, indexes, depth+1, variable_name, depth_string+"[{i}]")
+ else
+ print "The item at {variable_name}{depth_string}[{i}] is not a collection"
+ print item_i
+ end
+ end
+ else
+ print "Out of bounds exception : i = {i} and collection_length = {real_collection_length.to_s}"
+
+ if i < 0 then
+ continue
+ else if i >= real_collection_length then
+ break
+ end
+ end
+ end
+ else
+ if collection == null then
+ print "Cannot find {variable_name}{depth_string}"
+ else if real_collection_length != null then
+ print "Cannot find attribute length in {instance}"
+ else
+ print "Unknown error."
+ abort
+ end
+ end
+ end
+
+ #######################################################################
+ ## Variable Exploration functions ##
+ #######################################################################
+