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package ini
// ASTKind represents different states in the parse table
// and the type of AST that is being constructed
type ASTKind int
// ASTKind* is used in the parse table to transition between
// the different states
const (
ASTKindNone = ASTKind(iota)
ASTKindStart
ASTKindExpr
ASTKindEqualExpr
ASTKindStatement
ASTKindSkipStatement
ASTKindExprStatement
ASTKindSectionStatement
ASTKindNestedSectionStatement
ASTKindCompletedNestedSectionStatement
ASTKindCommentStatement
ASTKindCompletedSectionStatement
)
func (k ASTKind) String() string {
switch k {
case ASTKindNone:
return "none"
case ASTKindStart:
return "start"
case ASTKindExpr:
return "expr"
case ASTKindStatement:
return "stmt"
case ASTKindSectionStatement:
return "section_stmt"
case ASTKindExprStatement:
return "expr_stmt"
case ASTKindCommentStatement:
return "comment"
case ASTKindNestedSectionStatement:
return "nested_section_stmt"
case ASTKindCompletedSectionStatement:
return "completed_stmt"
case ASTKindSkipStatement:
return "skip"
default:
return ""
}
}
// AST interface allows us to determine what kind of node we
// are on and casting may not need to be necessary.
//
// The root is always the first node in Children
type AST struct {
Kind ASTKind
Root Token
RootToken bool
Children []AST
}
func newAST(kind ASTKind, root AST, children ...AST) AST {
return AST{
Kind: kind,
Children: append([]AST{root}, children...),
}
}
func newASTWithRootToken(kind ASTKind, root Token, children ...AST) AST {
return AST{
Kind: kind,
Root: root,
RootToken: true,
Children: children,
}
}
// AppendChild will append to the list of children an AST has.
func (a *AST) AppendChild(child AST) {
a.Children = append(a.Children, child)
}
// GetRoot will return the root AST which can be the first entry
// in the children list or a token.
func (a *AST) GetRoot() AST {
if a.RootToken {
return *a
}
if len(a.Children) == 0 {
return AST{}
}
return a.Children[0]
}
// GetChildren will return the current AST's list of children
func (a *AST) GetChildren() []AST {
if len(a.Children) == 0 {
return []AST{}
}
if a.RootToken {
return a.Children
}
return a.Children[1:]
}
// SetChildren will set and override all children of the AST.
func (a *AST) SetChildren(children []AST) {
if a.RootToken {
a.Children = children
} else {
a.Children = append(a.Children[:1], children...)
}
}
// Start is used to indicate the starting state of the parse table.
var Start = newAST(ASTKindStart, AST{})
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