woodpecker/vendor/github.com/drone/expr/parse/node.go
Matt Leung 4c2ff78d20 Add expression parser evaulator for build filter
Vendor github.com/drone/expr
Vendor github.com/drone/expr/parse
2017-09-08 19:39:24 -07:00

117 lines
2.3 KiB
Go

package parse
// Node is an element in the parse tree.
type Node interface {
node()
}
// ValExpr defines a value expression.
type ValExpr interface {
Node
value()
}
// BoolExpr defines a boolean expression.
type BoolExpr interface {
Node
bool()
}
// An expression is represented by a tree consisting of one
// or more of the following concrete expression nodes.
//
type (
// ComparisonExpr represents a two-value comparison expression.
ComparisonExpr struct {
Operator Operator
Left, Right ValExpr
}
// AndExpr represents an AND expression.
AndExpr struct {
Left, Right BoolExpr
}
// OrExpr represents an OR expression.
OrExpr struct {
Left, Right BoolExpr
}
// NotExpr represents a NOT expression.
NotExpr struct {
Expr BoolExpr
}
// ParenBoolExpr represents a parenthesized boolean expression.
ParenBoolExpr struct {
Expr BoolExpr
}
// BasicLit represents a basic literal.
BasicLit struct {
Kind Literal // INT, REAL, TEXT
Value []byte
}
// ArrayLit represents an array literal.
ArrayLit struct {
Values []ValExpr
}
// Field represents a value lookup by name.
Field struct {
Name []byte
}
)
// Operator identifies the type of operator.
type Operator int
// Comparison operators.
const (
OperatorEq Operator = iota
OperatorLt
OperatorLte
OperatorGt
OperatorGte
OperatorNeq
OperatorIn
OperatorRe
OperatorGlob
OperatorNotIn
OperatorNotRe
OperatorNotGlob
)
// Literal identifies the type of literal.
type Literal int
// The list of possible literal kinds.
const (
LiteralBool Literal = iota
LiteralInt
LiteralReal
LiteralText
)
// node() defines the node in a parse tree
func (x *ComparisonExpr) node() {}
func (x *AndExpr) node() {}
func (x *OrExpr) node() {}
func (x *NotExpr) node() {}
func (x *ParenBoolExpr) node() {}
func (x *BasicLit) node() {}
func (x *ArrayLit) node() {}
func (x *Field) node() {}
// bool() defines the node as a boolean expression.
func (x *ComparisonExpr) bool() {}
func (x *AndExpr) bool() {}
func (x *OrExpr) bool() {}
func (x *NotExpr) bool() {}
func (x *ParenBoolExpr) bool() {}
// value() defines the node as a value expression.
func (x *BasicLit) value() {}
func (x *ArrayLit) value() {}
func (x *Field) value() {}