Class CSTNode

  • Direct Known Subclasses:
    Reduction, Token

    public abstract class CSTNode
    extends Object
    An abstract base class for nodes in the concrete syntax tree that is the result of parsing. Note that the CSTNode is inextricably linked with the Token in that every CSTNode has a Token as its root.
    See Also:
    Token, Reduction, Types
    • Constructor Summary

      Constructors 
      Constructor Description
      CSTNode()  
    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      CSTNode add​(CSTNode element)
      Adds an element to the node.
      void addChildrenOf​(CSTNode of)
      Adds all children of the specified node to this one.
      abstract Reduction asReduction()
      Creates a Reduction from this node.
      boolean canMean​(int type)
      Returns true if the node can be coerced to the specified type.
      int children()
      Returns the number of non-root elements in the node.
      abstract CSTNode get​(int index)
      Returns the specified element, or null.
      CSTNode get​(int index, boolean safe)
      Returns the specified element, or Token.NULL if safe is set and the specified element is null (or doesn't exist).
      String getDescription()
      Returns a description of the node.
      int getMeaning()
      Returns the meaning of this node.
      int getMeaningAs​(int[] types)
      Returns the first matching meaning of the specified types.
      abstract Token getRoot()
      Returns the root of the node.
      Token getRoot​(boolean safe)
      Returns the root of the node, the Token that indicates its type.
      String getRootText()
      Returns the text of the root.
      int getStartColumn()
      Returns the starting column of the node.
      int getStartLine()
      Returns the starting line of the node.
      int getType()
      Returns the actual type of the node.
      boolean hasChildren()
      Returns true if the node has any non-root elements.
      boolean isA​(int type)
      Returns true if the node's meaning matches the specified type.
      boolean isAllOf​(int[] types)
      Returns true if the node's meaning matches all of the specified types.
      boolean isAnExpression()
      Returns true if the node is a complete expression.
      boolean isEmpty()
      Returns true if the node is completely empty (no root, even).
      boolean isOneOf​(int[] types)
      Returns true if the node's meaning matches any of the specified types.
      void markAsExpression()
      Marks the node a complete expression.
      CSTNode set​(int index, CSTNode element)
      Sets an element node in at the specified index.
      CSTNode setMeaning​(int meaning)
      Sets the meaning for this node (and its root Token).
      abstract int size()
      Returns the number of elements in the node (including root).
      String toString()
      Formats the node as a String and returns it.
      void write​(PrintWriter writer)
      Formats the node and writes it to the specified Writer.
      protected void write​(PrintWriter writer, String indent)
      Formats the node and writes it to the specified Writer.
    • Constructor Detail

      • CSTNode

        public CSTNode()
    • Method Detail

      • getMeaning

        public int getMeaning()
        Returns the meaning of this node. If the node isEmpty(), returns the type of Token.NULL.
      • setMeaning

        public CSTNode setMeaning​(int meaning)
        Sets the meaning for this node (and its root Token). Not valid if the node isEmpty(). Returns the node, for convenience.
      • getType

        public int getType()
        Returns the actual type of the node. If the node isEmpty(), returns the type of Token.NULL.
      • canMean

        public boolean canMean​(int type)
        Returns true if the node can be coerced to the specified type.
      • isA

        public boolean isA​(int type)
        Returns true if the node's meaning matches the specified type.
      • isOneOf

        public boolean isOneOf​(int[] types)
        Returns true if the node's meaning matches any of the specified types.
      • isAllOf

        public boolean isAllOf​(int[] types)
        Returns true if the node's meaning matches all of the specified types.
      • getMeaningAs

        public int getMeaningAs​(int[] types)
        Returns the first matching meaning of the specified types. Returns Types.UNKNOWN if there are no matches.
      • isEmpty

        public boolean isEmpty()
        Returns true if the node is completely empty (no root, even).
      • size

        public abstract int size()
        Returns the number of elements in the node (including root).
      • hasChildren

        public boolean hasChildren()
        Returns true if the node has any non-root elements.
      • children

        public int children()
        Returns the number of non-root elements in the node.
      • get

        public abstract CSTNode get​(int index)
        Returns the specified element, or null.
      • get

        public CSTNode get​(int index,
                           boolean safe)
        Returns the specified element, or Token.NULL if safe is set and the specified element is null (or doesn't exist).
      • getRoot

        public abstract Token getRoot()
        Returns the root of the node. By convention, all nodes have a Token as the first element (or root), which indicates the type of the node. May return null if the node isEmpty().
      • getRoot

        public Token getRoot​(boolean safe)
        Returns the root of the node, the Token that indicates its type. Returns a Token.NULL if safe and the actual root is null.
      • getRootText

        public String getRootText()
        Returns the text of the root. Uses getRoot(true) to get the root, so you will only receive null in return if the root token returns it.
      • getDescription

        public String getDescription()
        Returns a description of the node.
      • getStartLine

        public int getStartLine()
        Returns the starting line of the node. Returns -1 if not known.
      • getStartColumn

        public int getStartColumn()
        Returns the starting column of the node. Returns -1 if not known.
      • markAsExpression

        public void markAsExpression()
        Marks the node a complete expression. Not all nodes support this operation!
      • isAnExpression

        public boolean isAnExpression()
        Returns true if the node is a complete expression.
      • add

        public CSTNode add​(CSTNode element)
        Adds an element to the node. Returns the element for convenience. Not all nodes support this operation!
      • addChildrenOf

        public void addChildrenOf​(CSTNode of)
        Adds all children of the specified node to this one. Not all nodes support this operation!
      • set

        public CSTNode set​(int index,
                           CSTNode element)
        Sets an element node in at the specified index. Returns the element for convenience. Not all nodes support this operation!
      • asReduction

        public abstract Reduction asReduction()
        Creates a Reduction from this node. Returns self if the node is already a Reduction.
      • toString

        public String toString()
        Formats the node as a String and returns it.
        Overrides:
        toString in class Object
      • write

        public void write​(PrintWriter writer)
        Formats the node and writes it to the specified Writer.
      • write

        protected void write​(PrintWriter writer,
                             String indent)
        Formats the node and writes it to the specified Writer. The indent is prepended to each output line, and is increased for each recursion.