Module jdk.jshell

Package jdk.jshell

Class SourceCodeAnalysis

java.lang.Object

jdk.jshell.SourceCodeAnalysis

public abstract class SourceCodeAnalysis
extends Object

Provides analysis utilities for source code input. Optional functionality that provides for a richer interactive experience. Includes completion analysis: Is the input a complete snippet of code? Do I need to prompt for more input? Would adding a semicolon make it complete? Is there more than one snippet? etc. Also includes completion suggestions, as might be used in tab-completion.

Since:

9

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	SourceCodeAnalysis.Attribute	A span attribute which can be used to derive a coloring.
static enum	SourceCodeAnalysis.Completeness	Describes the completeness of the given input.
static interface	SourceCodeAnalysis.CompletionInfo	The result of analyzeCompletion(String input).
static interface	SourceCodeAnalysis.Documentation	A documentation for a candidate for continuation of the given user's input.
static final record	SourceCodeAnalysis.Highlight	Assigns attributes usable for coloring to spans inside a snippet.
static final class	SourceCodeAnalysis.QualifiedNames	List of possible qualified names.
static interface	SourceCodeAnalysis.SnippetWrapper	The wrapping of a snippet of Java source into valid top-level Java source.
static interface	SourceCodeAnalysis.Suggestion	A candidate for continuation of the given user's input.

Method Summary

Modifier and Type	Method	Description
abstract SourceCodeAnalysis.CompletionInfo	analyzeCompletion(String input)	Given an input string, find the first snippet of code (one statement, definition, import, or expression) and evaluate if it is complete.
abstract String	analyzeType(String code, int cursor)	Infer the type of the given expression.
abstract List<SourceCodeAnalysis.Suggestion>	completionSuggestions(String input, int cursor, int[] anchor)	Compute possible follow-ups for the given input.
abstract Collection<Snippet>	dependents(Snippet snippet)	Returns a collection of Snippets which might need updating if the given Snippet is updated.
abstract List<SourceCodeAnalysis.Documentation>	documentation(String input, int cursor, boolean computeJavadoc)	Compute documentation for the given user's input.
abstract List<SourceCodeAnalysis.Highlight>	highlights(String snippet)	Returns a collection of Highlights which can be used to color the given snippet.
abstract SourceCodeAnalysis.QualifiedNames	listQualifiedNames(String code, int cursor)	List qualified names known for the simple name in the given code immediately to the left of the given cursor position.
abstract List<Snippet>	sourceToSnippets(String input)	Converts the source code of a snippet into a Snippet object (or list of Snippet objects in the case of some var declarations, e.g.: int x, y, z;).
abstract SourceCodeAnalysis.SnippetWrapper	wrapper(Snippet snippet)	Returns the wrapper information for the Snippet.
abstract List<SourceCodeAnalysis.SnippetWrapper>	wrappers(String input)	Returns the wrapper information for the snippet within the input source string.

Methods declared in class java.lang.Object

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

Method Details

analyzeCompletion

public abstract SourceCodeAnalysis.CompletionInfo analyzeCompletion(String input)

Given an input string, find the first snippet of code (one statement, definition, import, or expression) and evaluate if it is complete.

Parameters:

input - the input source string

Returns:

a CompletionInfo instance with location and completeness info

completionSuggestions

public abstract List<SourceCodeAnalysis.Suggestion> completionSuggestions(String input,
 int cursor,
 int[] anchor)

Compute possible follow-ups for the given input. Uses information from the current JShell state, including type information, to filter the suggestions.

Parameters:

input - the user input, so far

cursor - the current position of the cursors in the given input text

anchor - outgoing parameter - when an option will be completed, the text between the anchor and cursor will be deleted and replaced with the given option

Returns:

list of candidate continuations of the given input.

documentation

public abstract List<SourceCodeAnalysis.Documentation> documentation(String input,
 int cursor,
 boolean computeJavadoc)

Compute documentation for the given user's input. Multiple Documentation objects may be returned when multiple elements match the user's input (like for overloaded methods).

Parameters:

input - the snippet the user wrote so far

cursor - the current position of the cursors in the given input text

computeJavadoc - true if the javadoc for the given input should be computed in addition to the signature

Returns:

the documentations for the given user's input, if multiple elements match the input, multiple Documentation objects are returned.

analyzeType

public abstract String analyzeType(String code,
 int cursor)

Infer the type of the given expression. The expression spans from the beginning of code to the given cursor position. Returns null if the type of the expression cannot be inferred.

Parameters:

code - the expression for which the type should be inferred

cursor - current cursor position in the given code

Returns:

the inferred type, or null if it cannot be inferred

listQualifiedNames

public abstract SourceCodeAnalysis.QualifiedNames listQualifiedNames(String code,
 int cursor)

List qualified names known for the simple name in the given code immediately to the left of the given cursor position. The qualified names are gathered by inspecting the classpath used by eval (see JShell.addToClasspath(java.lang.String)).

Parameters:

code - the expression for which the candidate qualified names should be computed

cursor - current cursor position in the given code

Returns:

the known qualified names

wrapper

public abstract SourceCodeAnalysis.SnippetWrapper wrapper(Snippet snippet)

Returns the wrapper information for the Snippet. The wrapper changes as the environment changes, so calls to this method at different times may yield different results.

Parameters:

snippet - the Snippet from which to retrieve the wrapper

Returns:

information on the wrapper

wrappers

public abstract List<SourceCodeAnalysis.SnippetWrapper> wrappers(String input)

Returns the wrapper information for the snippet within the input source string.

Wrapper information for malformed and incomplete snippets also generate wrappers. The list is in snippet encounter order. The wrapper changes as the environment changes, so calls to this method at different times may yield different results.

The input should be exactly one complete snippet of source code, that is, one expression, statement, variable declaration, method declaration, class declaration, or import. To break arbitrary input into individual complete snippets, use analyzeCompletion(String).

The wrapper may not match that returned by wrapper(Snippet), were the source converted to a Snippet.

Parameters:

input - the source input from which to generate wrappers

Returns:

a list of wrapper information

sourceToSnippets

public abstract List<Snippet> sourceToSnippets(String input)

Converts the source code of a snippet into a Snippet object (or list of Snippet objects in the case of some var declarations, e.g.: int x, y, z;). Does not install the snippets: declarations are not accessible by other snippets; imports are not added. Does not execute the snippets.

Queries may be done on the Snippet object. The Snippet.id() will be "*UNASSOCIATED*". The returned snippets are not associated with the JShell instance, so attempts to pass them to JShell methods will throw an IllegalArgumentException. They will not appear in queries for snippets -- for example, JShell.snippets().

Restrictions on the input are as in JShell.eval.

Only preliminary compilation is performed, sufficient to build the Snippet. Snippets known to be erroneous, are returned as ErroneousSnippet, other snippets may or may not be in error.

Parameters:

input - The input String to convert

Returns:

usually a singleton list of Snippet, but may be empty or multiple

Throws:

IllegalStateException - if the JShell instance is closed.

dependents

public abstract Collection<Snippet> dependents(Snippet snippet)

Returns a collection of Snippets which might need updating if the given Snippet is updated. The returned collection is designed to be inclusive and may include many false positives.

Parameters:

snippet - the Snippet whose dependents are requested

Returns:

the collection of dependents

highlights

public abstract List<SourceCodeAnalysis.Highlight> highlights(String snippet)

Returns a collection of Highlights which can be used to color the given snippet.

The returned Highlights do not overlap, and are sorted by their start position.

Parameters:

snippet - the snippet for which the Highlights should be computed

Returns:

the computed Highlights.

Since:

19