diff options
Diffstat (limited to 'vendor/github.com/pelletier/go-toml/v2/unstable/ast.go')
-rw-r--r-- | vendor/github.com/pelletier/go-toml/v2/unstable/ast.go | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/vendor/github.com/pelletier/go-toml/v2/unstable/ast.go b/vendor/github.com/pelletier/go-toml/v2/unstable/ast.go new file mode 100644 index 00000000..b60d9bfd --- /dev/null +++ b/vendor/github.com/pelletier/go-toml/v2/unstable/ast.go @@ -0,0 +1,136 @@ +package unstable + +import ( + "fmt" + "unsafe" + + "github.com/pelletier/go-toml/v2/internal/danger" +) + +// Iterator over a sequence of nodes. +// +// Starts uninitialized, you need to call Next() first. +// +// For example: +// +// it := n.Children() +// for it.Next() { +// n := it.Node() +// // do something with n +// } +type Iterator struct { + started bool + node *Node +} + +// Next moves the iterator forward and returns true if points to a +// node, false otherwise. +func (c *Iterator) Next() bool { + if !c.started { + c.started = true + } else if c.node.Valid() { + c.node = c.node.Next() + } + return c.node.Valid() +} + +// IsLast returns true if the current node of the iterator is the last +// one. Subsequent calls to Next() will return false. +func (c *Iterator) IsLast() bool { + return c.node.next == 0 +} + +// Node returns a pointer to the node pointed at by the iterator. +func (c *Iterator) Node() *Node { + return c.node +} + +// Node in a TOML expression AST. +// +// Depending on Kind, its sequence of children should be interpreted +// differently. +// +// - Array have one child per element in the array. +// - InlineTable have one child per key-value in the table (each of kind +// InlineTable). +// - KeyValue have at least two children. The first one is the value. The rest +// make a potentially dotted key. +// - Table and ArrayTable's children represent a dotted key (same as +// KeyValue, but without the first node being the value). +// +// When relevant, Raw describes the range of bytes this node is refering to in +// the input document. Use Parser.Raw() to retrieve the actual bytes. +type Node struct { + Kind Kind + Raw Range // Raw bytes from the input. + Data []byte // Node value (either allocated or referencing the input). + + // References to other nodes, as offsets in the backing array + // from this node. References can go backward, so those can be + // negative. + next int // 0 if last element + child int // 0 if no child +} + +// Range of bytes in the document. +type Range struct { + Offset uint32 + Length uint32 +} + +// Next returns a pointer to the next node, or nil if there is no next node. +func (n *Node) Next() *Node { + if n.next == 0 { + return nil + } + ptr := unsafe.Pointer(n) + size := unsafe.Sizeof(Node{}) + return (*Node)(danger.Stride(ptr, size, n.next)) +} + +// Child returns a pointer to the first child node of this node. Other children +// can be accessed calling Next on the first child. Returns an nil if this Node +// has no child. +func (n *Node) Child() *Node { + if n.child == 0 { + return nil + } + ptr := unsafe.Pointer(n) + size := unsafe.Sizeof(Node{}) + return (*Node)(danger.Stride(ptr, size, n.child)) +} + +// Valid returns true if the node's kind is set (not to Invalid). +func (n *Node) Valid() bool { + return n != nil +} + +// Key returns the children nodes making the Key on a supported node. Panics +// otherwise. They are guaranteed to be all be of the Kind Key. A simple key +// would return just one element. +func (n *Node) Key() Iterator { + switch n.Kind { + case KeyValue: + value := n.Child() + if !value.Valid() { + panic(fmt.Errorf("KeyValue should have at least two children")) + } + return Iterator{node: value.Next()} + case Table, ArrayTable: + return Iterator{node: n.Child()} + default: + panic(fmt.Errorf("Key() is not supported on a %s", n.Kind)) + } +} + +// Value returns a pointer to the value node of a KeyValue. +// Guaranteed to be non-nil. Panics if not called on a KeyValue node, +// or if the Children are malformed. +func (n *Node) Value() *Node { + return n.Child() +} + +// Children returns an iterator over a node's children. +func (n *Node) Children() Iterator { + return Iterator{node: n.Child()} +} |