Context

Holds the variables and consts of a script stack frame. The global context can be accessed by climbing the Context.parent chain until reaching the Context whose parent is null. This allows native functions to define local and global variables. Note that calling a native function does not create a stack frame so one could write a native function that adds local variables to the stack frame where it was called.

class Context {

this(Context par, string nam);

this(Interpreter interpreter);

ScriptAny* lookupVariableOrConst(string varName, bool isConst);

void unsetVariable(string name);

bool declareVariableOrConst(string nam, ScriptAny value, bool isConst);

bool variableOrConstExists(string name);

ScriptAny* reassignVariable(string name, ScriptAny newValue, bool failedBecauseConst);

void forceSetVarOrConst(string name, ScriptAny value, bool isConst);

void forceRemoveVarOrConst(string name);

Context getGlobalContext();

void insertLabel(string label);

Interpreter interpreter();

bool labelExists(string label);

void removeLabelFromCurrent(string label);

Context parent();

string name();

string toString();

}

Constructors

this this(Context par, string nam): Constructs a new Context.
this this(Interpreter interpreter): Constructs a global context

Members

Functions

declareVariableOrConst bool declareVariableOrConst(string nam, ScriptAny value, bool isConst): Attempt to declare and assign a new variable in the current context. Returns false if it already exists.
forceRemoveVarOrConst void forceRemoveVarOrConst(string name): Forces the removal of a const or variable in the current context.
forceSetVarOrConst void forceSetVarOrConst(string name, ScriptAny value, bool isConst): Force sets a variable or const no matter if the variable was declared already or is const. This is used by the host application to set globals or locals.
getGlobalContext Context getGlobalContext(): climb context stack until finding one without a parent
insertLabel void insertLabel(string label): inserts a label into the list of valid labels
interpreter Interpreter interpreter(): Retrieves the interpreter object from the top level context
labelExists bool labelExists(string label): checks context stack for a label
lookupVariableOrConst ScriptAny* lookupVariableOrConst(string varName, bool isConst): Attempts to look up existing variable or const throughout the stack. If found, returns a pointer to the variable location, and if it is const, sets isConst to true. Note, this pointer should not be stored by native functions because the variable table may be modified between function calls.
name string name(): returns the name property of the Context
parent Context parent(): returns the parent property
reassignVariable ScriptAny* reassignVariable(string name, ScriptAny newValue, bool failedBecauseConst): Attempts to reassign a variable anywhere in the stack and returns a pointer to the variable or null if the variable doesn't exist or is const. If the failure is due to const, failedBecauseConst is set to true. Note: this pointer should not be stored by native functions due to modifications to the variable table that may invalidate it and result in undefined behavior.
removeLabelFromCurrent void removeLabelFromCurrent(string label): removes a label from the existing context
toString string toString(): Returns a string representing the type and name
unsetVariable void unsetVariable(string name): Removes a variable from anywhere on the Context stack it is located. This function cannot be used to unset consts.
variableOrConstExists bool variableOrConstExists(string name): Searches the entire Context stack for a variable starting with the current context and climbing the parent chain.

Context

Constructors

Members

Functions

Meta

Source