FieldPath (General SQL Parser Java Library Core 4.1.0.5 API)

Object
- gudusoft.gsqlparser.resolver2.model.FieldPath

```
public class FieldPath
extends Object
```
Represents a field path for deep/record field access in structured types.
In BigQuery, Snowflake, and other databases with STRUCT/RECORD types, column references can include field paths like customer.address.city. This class captures the field path portion (segments beyond the base column).

Design principles:
- Immutable - once created, cannot be modified
- Only stores segments beyond the base column (e.g., for customer.address.city, if base column is customer, fieldPath stores ["address", "city"])
- Empty fieldPath means no field access (regular column reference)
Example:
```
 -- SQL: SELECT customer.address.city FROM orders
 -- base column: customer
 -- fieldPath: ["address", "city"]
 
```
See Also:

ColumnSource.getFieldPath()

Field Summary

Fields
Modifier and Type Field and Description

static FieldPath EMPTY
Empty field path singleton for regular column references

Fields
Modifier and Type	Field and Description
`static FieldPath`	`EMPTY` Empty field path singleton for regular column references

Constructor Summary

Constructors
Constructor and Description

FieldPath(List<String> segments)
Create a FieldPath from a list of segments.

Constructors
Constructor and Description
`FieldPath(List<String> segments)` Create a FieldPath from a list of segments.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`FieldPath`	`append(FieldPath other)` Create a new FieldPath with additional segments appended.
`FieldPath`	`append(String segment)` Create a new FieldPath with an additional segment appended.
`boolean`	`equals(Object o)`
`String`	`get(int index)` Get a segment by index.
`String`	`getFirst()` Get the first segment (immediate field).
`String`	`getLast()` Get the last segment (deepest field).
`List<String>`	`getSegments()` Get the field path segments.
`int`	`hashCode()`
`boolean`	`isEmpty()` Check if this field path is empty (no field access).
`static FieldPath`	`of(List<String> segments)` Create a FieldPath from a list of segments.
`static FieldPath`	`of(String... segments)` Create a FieldPath from multiple segments.
`static FieldPath`	`of(String segment)` Create a FieldPath from a single segment.
`int`	`size()` Get the number of segments in this field path.
`FieldPath`	`subPath(int fromIndex)` Create a sub-path starting from the given index.
`String`	`toFullReference(String baseColumn)` Convert to full reference string with base column.
`String`	`toString()` Convert to dot-separated string representation.

Methods inherited from class Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - EMPTY
```
public static final FieldPath EMPTY
```
    Empty field path singleton for regular column references
- Constructor Detail
  - FieldPath
```
public FieldPath(List<String> segments)
```
    Create a FieldPath from a list of segments.
    
    Parameters:
    
    segments - The field path segments (will be copied)
- Method Detail
  - of
```
public static FieldPath of(String segment)
```
    Create a FieldPath from a single segment.
    
    Parameters:
    
    segment - The single field segment
    
    Returns:
    
    A new FieldPath with one segment
  - of
```
public static FieldPath of(String... segments)
```
    Create a FieldPath from multiple segments.
    
    Parameters:
    
    segments - The field segments
    
    Returns:
    
    A new FieldPath
  - of
```
public static FieldPath of(List<String> segments)
```
    Create a FieldPath from a list of segments.
    
    Parameters:
    
    segments - The field segments
    
    Returns:
    
    A new FieldPath, or EMPTY if null/empty
  - getSegments
```
public List<String> getSegments()
```
    Get the field path segments.
    
    Returns:
    
    Unmodifiable list of segments
  - size
```
public int size()
```
    Get the number of segments in this field path.
    
    Returns:
    
    Number of segments
  - isEmpty
```
public boolean isEmpty()
```
    Check if this field path is empty (no field access).
    
    Returns:
    
    true if empty
  - getFirst
```
public String getFirst()
```
    Get the first segment (immediate field).
    
    Returns:
    
    First segment, or null if empty
  - getLast
```
public String getLast()
```
    Get the last segment (deepest field).
    
    Returns:
    
    Last segment, or null if empty
  - get
```
public String get(int index)
```
    Get a segment by index.
    
    Parameters:
    
    index - The index
    
    Returns:
    
    The segment at that index
    
    Throws:
    
    IndexOutOfBoundsException - if index is invalid
  - append
```
public FieldPath append(String segment)
```
    Create a new FieldPath with an additional segment appended.
    
    Parameters:
    
    segment - The segment to append
    
    Returns:
    
    New FieldPath with the segment appended
  - append
```
public FieldPath append(FieldPath other)
```
    Create a new FieldPath with additional segments appended.
    
    Parameters:
    
    other - The FieldPath to append
    
    Returns:
    
    New FieldPath with all segments
  - subPath
```
public FieldPath subPath(int fromIndex)
```
    Create a sub-path starting from the given index.
    
    Parameters:
    
    fromIndex - Start index (inclusive)
    
    Returns:
    
    New FieldPath with segments from fromIndex
  - toString
```
public String toString()
```
    Convert to dot-separated string representation.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    String like "address.city", or empty string if empty
  - toFullReference
```
public String toFullReference(String baseColumn)
```
    Convert to full reference string with base column.
    
    Parameters:
    
    baseColumn - The base column name
    
    Returns:
    
    String like "customer.address.city"
  - equals
```
public boolean equals(Object o)
```
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object

Class FieldPath

Field Summary

Constructor Summary

Method Summary

Methods inherited from class Object

Field Detail

EMPTY

Constructor Detail

FieldPath

Method Detail

of

of

of

getSegments

size

isEmpty

getFirst

getLast

get

append

append

subPath

toString

toFullReference

equals

hashCode