IsUnknown reports whether a variable is unknown or contains any value that is unknown.

MustNewLiteralNode wraps NewLiteralNode and panics if an error is returned, thus allowing valid literal nodes to be easily assigned to global variables.

NewLiteralNode returns a new literal node representing the given literal Go value, which must correspond to one of the primitive types supported by HIL.

NewVariable creates a new Variable for the given value.

This is a special type used by Terraform to mark "unknown" values.

InitPos is an initiaial position value.

Arithmetic represents a node where the result is arithmetic of two or more operands in the order given.

BasicScope is a simple scope that looks up variables and functions using a map.

Call represents a function call.

Function defines a function that can be executed by the engine.

Index represents an indexing operation into another data structure.

LiteralNode represents a single literal value, such as "foo" or 42 or 3.14159.

Output represents the root node of all interpolation evaluations.

Pos is the starting position of an AST node.

Stack is a stack of Node.

Variable is a variable value for execution given as input to the engine.

VariableAccess represents a variable access.

Node is the interface that all AST nodes must implement.

Scope is the interface used to look up variables and functions while evaluating.

ArithmeticOp is the operation to use for the math.

Type is the type of any value.

Visitors are just implementations of this function.