bytecode

const (
	// OpConstant defines a constant that will be referred to by index
	// in the bytecode.
	OpConstant Opcode = iota
	// OpGetGlobal retrieves a symbol from the symbol table at the
	// specified index.
	OpGetGlobal
	// OpSetGlobal adds a symbol to the specified index in the symbol
	// table.
	OpSetGlobal
	// OpAdd instructs the virtual machine to perform an addition.
	OpAdd
	// OpSubtract instructs the virtual machine to perform a subtraction.
	OpSubtract
	// OpMultiply instructs the virtual machine to perform a multiplication.
	OpMultiply
	// OpDivide instructs the virtual machine to perform a division.
	OpDivide
	// OpModulo instructs the virtual machine to perform a modulo operation.
	// Modulo returns the remainder of dividing the left side of an expression
	// by the right.
	OpModulo
	// OpTrue represents the boolean literal true.
	OpTrue
	// OpFalse represents the boolean literal false.
	OpFalse
	// OpNot represents the not unary operator, which performs logical
	// negation on a boolean operand.
	OpNot
	// OpMinus represents the minus unary operator, which negates the
	// value of a numeric operand.
	OpMinus
	// OpEqual represents the equality operator.
	OpEqual
	// OpNotEqual represents the inequality operator.
	OpNotEqual
	// OpNumLessThan represents a less than operator for numeric
	// operands.
	OpNumLessThan
	// OpNumLessThanEqual represents a less than or equal operator for
	// numeric operands.
	OpNumLessThanEqual
	// OpNumGreaterThan represents a greater than operator for numeric
	// operands.
	OpNumGreaterThan
	// OpNumGreaterThanEqual represents a greater than or equal operator
	// for numeric operands.
	OpNumGreaterThanEqual
	// OpStringLessThan represents a less than operator for string
	// operands. Strings are compared using lexicographic order.
	OpStringLessThan
	// OpStringLessThanEqual represents a less than or equal operator for
	// string operands. Strings are compared using lexicographic order.
	OpStringLessThanEqual
	// OpStringGreaterThan represents a greater than operator for string
	// operands. Strings are compared using lexicographic order.
	OpStringGreaterThan
	// OpStringGreaterThanEqual represents a greater than or equal operator
	// for string operands. Strings are compared using lexicographic order.
	OpStringGreaterThanEqual
	// OpStringConcatenate represents a + operator used to concatenate two
	// strings.
	OpStringConcatenate
	// OpArray represents an array literal, the operand N is the length of
	// the array, and instructs the vm to pop N elements from the stack.
	OpArray
	// OpArrayConcatenate represents a + operator used to concatenate two
	// arrays.
	OpArrayConcatenate
	// OpArrayRepeat represents a * operator used to repeat an array a
	// number of times.
	OpArrayRepeat
	// OpMap represents a map literal, the operand N is the length of
	// the map multiplied by 2. This length N represents the total length
	// of the flattened map in the stack, where keys and values have been
	// pushed sequentially (k1, v1, k2, v2...).
	OpMap
	// OpIndex represents an index operator used on an array, map or
	// string variable.
	OpIndex
	// OpSetIndex represents an index operator on the left hand side of
	// an assignment.
	OpSetIndex
	// OpSlice represents a slice operator used on an array or string. The top
	// three elements are read from the stack and are the end index, start index
	// and the data structure being operated on. OpNone is used as a default
	// when the start or end are not specified by the user program.
	OpSlice
	// OpNone represents an unspecified value used where values are
	// optional and unspecified such as the start and end value of a
	// slice index, or the values in a step range.
	OpNone
	// OpJump will force the virtual machine to jump to the instruction
	// address within its operand.
	OpJump
	// OpJumpOnFalse will pop the top element of the stack as a
	// boolean and evaluate it. It will jump to the instruction address
	// in its operand if the condition evaluates to false.
	OpJumpOnFalse
)

const (
	// GlobalScope is the top level scope of an evy program.
	GlobalScope SymbolScope = "GLOBAL"
)