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