jminusminus

Class JArrayExpression

java.lang.Object

jminusminus.JAST

jminusminus.JStatement

jminusminus.JExpression

jminusminus.JArrayExpression

All Implemented Interfaces:

JLhs

 class JArrayExpression
extends JExpression
implements JLhs

The AST for an array indexing operation. It has an expression denoting an array object and an expression denoting an integer index.

Field Summary

Fields inherited from class jminusminus.JExpression

isStatementExpression, type

Fields inherited from class jminusminus.JAST

compilationUnit, line

Constructor Summary

Constructors

Constructor and Description
JArrayExpression(int line, JExpression theArray, JExpression indexExpr) Construct an AST node for an array indexing operation.

Method Summary

Methods

Modifier and Type	Method and Description
JExpression	analyze(Context context) Perform semantic analysis on an array indexing expression such as A[i].
JExpression	analyzeLhs(Context context) Analyzing the array expression as an Lvalue is like analyzing it for its Rvalue.
void	codegen(CLEmitter output) Perform code generation from the JArrayExpression using the specified code emitter.
void	codegenDuplicateRvalue(CLEmitter output) Generate the code required for duplicating the Rvalue that is on the stack becuase it is to be used in a surrounding expression, as in a[i] = x = or x = y--.
void	codegenLoadLhsLvalue(CLEmitter output) Generate the code required for setting up an Lvalue, eg for use in an assignment.
void	codegenLoadLhsRvalue(CLEmitter output) Generate the code required for loading an Rvalue for this variable, eg for use in a +=.
void	codegenStore(CLEmitter output) Generate the code required for doing the actual assignment.
void	writeToStdOut(PrettyPrinter p) Write the information pertaining to this AST to STDOUT.

Methods inherited from class jminusminus.JExpression

codegen, isStatementExpression, type

Methods inherited from class jminusminus.JAST

line, partialCodegen

Methods inherited from class java.lang.Object

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

Constructor Detail

JArrayExpression

public JArrayExpression(int line,
                JExpression theArray,
                JExpression indexExpr)

Construct an AST node for an array indexing operation.

Parameters:

line - line in which the operation occurs in the source file.

theArray - the array we're indexing.

indexExpr - the index expression.

Method Detail

analyze

public JExpression analyze(Context context)

Perform semantic analysis on an array indexing expression such as A[i].

Specified by:

analyze in class JExpression

Parameters:

context - context in which names are resolved.

Returns:

the analyzed (and possibly rewritten) AST subtree.

analyzeLhs

public JExpression analyzeLhs(Context context)

Analyzing the array expression as an Lvalue is like analyzing it for its Rvalue.

Specified by:

analyzeLhs in interface JLhs

Parameters:

context - context in which names are resolved.

Returns:

the analyzed (and possibly rewritten) AST subtree.

codegen

public void codegen(CLEmitter output)

Perform code generation from the JArrayExpression using the specified code emitter. Generate the code necessary for loading the Rvalue.

Specified by:

codegen in class JAST

Parameters:

output - the code emitter (basically an abstraction for producing the .class file).

codegenLoadLhsLvalue

public void codegenLoadLhsLvalue(CLEmitter output)

Generate the code required for setting up an Lvalue, eg for use in an assignment. Here, this requires loading the array and the index.

Specified by:

codegenLoadLhsLvalue in interface JLhs

Parameters:

output - the code emitter (basically an abstraction for producing the .class file).

codegenLoadLhsRvalue

public void codegenLoadLhsRvalue(CLEmitter output)

Generate the code required for loading an Rvalue for this variable, eg for use in a +=. Here, this requires duplicating the array and the index on the stack and doing an array load.

Specified by:

codegenLoadLhsRvalue in interface JLhs

Parameters:

output - the code emitter (basically an abstraction for producing the .class file).

codegenDuplicateRvalue

public void codegenDuplicateRvalue(CLEmitter output)

Generate the code required for duplicating the Rvalue that is on the stack becuase it is to be used in a surrounding expression, as in a[i] = x = or x = y--. Here this means copying it down two locations (beneath the array and index).

Specified by:

codegenDuplicateRvalue in interface JLhs

Parameters:

output - the code emitter (basically an abstraction for producing the .class file).

codegenStore

public void codegenStore(CLEmitter output)

Generate the code required for doing the actual assignment. Here, this requires an array store.

Specified by:

codegenStore in interface JLhs

Parameters:

output - the code emitter (basically an abstraction for producing the .class file).

writeToStdOut

public void writeToStdOut(PrettyPrinter p)

Description copied from class: JAST

Write the information pertaining to this AST to STDOUT.

Specified by:

writeToStdOut in class JAST

Parameters:

p - for pretty printing with indentation.