Package org.codehaus.groovy.syntax

Class CSTNode

java.lang.Object
org.codehaus.groovy.syntax.CSTNode
Direct Known Subclasses:
Reduction, Token
public abstract class CSTNode extends Object
Abstract base class for nodes in the concrete syntax tree (CST) produced by parsing. Every CST node has a Token as its root element, which indicates the node's type. This class provides methods for querying node meaning, type, structure, and converting between different node representations.
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    CSTNode()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    CSTNode
    add(CSTNode element)
    Adds an element to this node.
    void
    addChildrenOf(CSTNode of)
    Adds all children of the specified node to this node.
    abstract Reduction
    asReduction()
    Converts this node to a Reduction.
    boolean
    canMean(int type)
    Returns true if this node can be coerced to the specified type.
    int
    children()
    Returns the number of child elements (excluding the root).
    abstract CSTNode
    get(int index)
    Returns the element at the specified index, or null if not found.
    CSTNode
    get(int index, boolean safe)
    Returns the element at the specified index, or Token.NULL if the element is not found and safe is true.
    String
    getDescription()
    Returns a human-readable description of this node's semantic meaning.
    int
    getMeaning()
    Returns the current semantic meaning (interpretation) of this node.
    int
    getMeaningAs(int[] types)
    Returns the first matching meaning of the specified types.
    abstract Token
    getRoot()
    Returns the root token of this node.
    Token
    getRoot(boolean safe)
    Returns the root token of this node, returning Token.NULL if the actual root is null and safe is true.
    String
    getRootText()
    Returns the text content of the root token.
    int
    getStartColumn()
    Returns the starting column number of this node in the source.
    int
    getStartLine()
    Returns the starting line number of this node in the source.
    int
    getType()
    Returns the actual syntactic type of this node as determined by the parser.
    boolean
    hasChildren()
    Returns true if this node has any children (non-root elements).
    boolean
    isA(int type)
    Returns true if this node's meaning matches the specified type.
    boolean
    isAllOf(int[] types)
    Returns true if this node's meaning matches all of the specified types.
    boolean
    isAnExpression()
    Returns true if this node represents a complete expression.
    boolean
    isEmpty()
    Returns true if this node is completely empty (no root element).
    boolean
    isOneOf(int[] types)
    Returns true if this node's meaning matches any of the specified types.
    void
    markAsExpression()
    Marks this node as a complete expression.
    CSTNode
    set(int index, CSTNode element)
    Sets the element at the specified index.
    CSTNode
    setMeaning(int meaning)
    Sets the semantic meaning (interpretation) of this node.
    abstract int
    size()
    Returns the number of elements in this node (including the root).
    String
    toString()
    Returns a formatted string representation of this node and its children.
    void
    write(PrintWriter writer)
    Writes a formatted representation of this node to the specified writer.
    protected void
    write(PrintWriter writer, String indent)
    Writes a formatted representation of this node to the specified writer, with indentation for readability.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • CSTNode

      public CSTNode()

  • Method Details

    • getMeaning

      public int getMeaning()
      Returns the current semantic meaning (interpretation) of this node. For nodes without a root, returns Types.UNKNOWN.
      Returns:
      the node's meaning type from Types

    • setMeaning

      public CSTNode setMeaning(int meaning)
      Sets the semantic meaning (interpretation) of this node. The meaning may differ from the node's actual type and is often assigned during semantic analysis after parsing.
      Parameters:
      meaning - the new meaning type from Types
      Returns:
      this node for convenience chaining

    • getType

      public int getType()
      Returns the actual syntactic type of this node as determined by the parser. For nodes without a root, returns Types.UNKNOWN.
      Returns:
      the node's type from Types

    • canMean

      public boolean canMean(int type)
      Returns true if this node can be coerced to the specified type. This is determined by the type hierarchy defined in Types.
      Parameters:
      type - the type to check against
      Returns:
      true if coercion is possible

    • isA

      public boolean isA(int type)
      Returns true if this node's meaning matches the specified type.
      Parameters:
      type - the type to check
      Returns:
      true if the node's meaning is of the specified type

    • isOneOf

      public boolean isOneOf(int[] types)
      Returns true if this node's meaning matches any of the specified types.
      Parameters:
      types - an array of types to check
      Returns:
      true if the node's meaning matches at least one of the types

    • isAllOf

      public boolean isAllOf(int[] types)
      Returns true if this node's meaning matches all of the specified types.
      Parameters:
      types - an array of types to check
      Returns:
      true if the node's meaning matches all of the types

    • getMeaningAs

      public int getMeaningAs(int[] types)
      Returns the first matching meaning of the specified types. Useful for determining which of several possible meanings this node has.
      Parameters:
      types - an array of types to check
      Returns:
      the first matching type, or Types.UNKNOWN if no match is found

    • isEmpty

      public boolean isEmpty()
      Returns true if this node is completely empty (no root element).
      Returns:
      true if empty, false otherwise

    • size

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

    • hasChildren

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

    • children

      public int children()
      Returns the number of child elements (excluding the root).
      Returns:
      the number of children

    • get

      public abstract CSTNode get(int index)
      Returns the element at the specified index, or null if not found.
      Parameters:
      index - the element index (0 for root)
      Returns:
      the element at the index, or null

    • get

      public CSTNode get(int index, boolean safe)
      Returns the element at the specified index, or Token.NULL if the element is not found and safe is true.
      Parameters:
      index - the element index
      safe - if true, returns Token.NULL instead of null for missing elements
      Returns:
      the element at the index, Token.NULL if safe and missing, or null

    • getRoot

      public abstract Token getRoot()
      Returns the root token of this node. By convention, all nodes have a Token as their root element (at index 0), which indicates the syntactic type of the node.
      Returns:
      the root token, or null if the node is empty

    • getRoot

      public Token getRoot(boolean safe)
      Returns the root token of this node, returning Token.NULL if the actual root is null and safe is true.
      Parameters:
      safe - if true, returns Token.NULL instead of null
      Returns:
      the root token

    • getRootText

      public String getRootText()
      Returns the text content of the root token. Uses getRoot(true) to ensure a non-null root.
      Returns:
      the text of the root token

    • getDescription

      public String getDescription()
      Returns a human-readable description of this node's semantic meaning.
      Returns:
      a description string from Types

    • getStartLine

      public int getStartLine()
      Returns the starting line number of this node in the source.
      Returns:
      the line number (1-based), or -1 if not known

    • getStartColumn

      public int getStartColumn()
      Returns the starting column number of this node in the source.
      Returns:
      the column number (1-based), or -1 if not known

    • markAsExpression

      public void markAsExpression()
      Marks this node as a complete expression. Not all node types support this operation.
      Throws:
      GroovyBugError - if this node type does not support marking

    • isAnExpression

      public boolean isAnExpression()
      Returns true if this node represents a complete expression.
      Returns:
      true if this is an expression

    • add

      public CSTNode add(CSTNode element)
      Adds an element to this node. Not all node types support this operation.
      Parameters:
      element - the element to add
      Returns:
      the added element
      Throws:
      GroovyBugError - if this node type does not support adding

    • addChildrenOf

      public void addChildrenOf(CSTNode of)
      Adds all children of the specified node to this node. Skips the root element and copies only the children.
      Parameters:
      of - the source node whose children are to be copied

    • set

      public CSTNode set(int index, CSTNode element)
      Sets the element at the specified index. Not all node types support this operation.
      Parameters:
      index - the element index
      element - the element to set
      Returns:
      the set element
      Throws:
      GroovyBugError - if this node type does not support setting

    • asReduction

      public abstract Reduction asReduction()
      Converts this node to a Reduction. If this node is already a Reduction, returns itself.
      Returns:
      this node as a Reduction

    • toString

      public String toString()
      Returns a formatted string representation of this node and its children.
      Overrides:
      toString in class Object
      Returns:
      the formatted node tree as a string

    • write

      public void write(PrintWriter writer)
      Writes a formatted representation of this node to the specified writer.
      Parameters:
      writer - the PrintWriter to write to

    • write

      protected void write(PrintWriter writer, String indent)
      Writes a formatted representation of this node to the specified writer, with indentation for readability. The indentation is increased for each level of recursion to show the tree structure.
      Parameters:
      writer - the PrintWriter to write to
      indent - the indentation string to prepend to each line