jminusminus

Class JLogicalNotOp

java.lang.Object

jminusminus.JAST

jminusminus.JStatement

jminusminus.JExpression

jminusminus.JUnaryExpression

jminusminus.JLogicalNotOp

 class JLogicalNotOp
extends JUnaryExpression

The AST node for a logical NOT (!) expression.

Field Summary

Fields inherited from class jminusminus.JUnaryExpression

arg

Fields inherited from class jminusminus.JExpression

isStatementExpression, type

Fields inherited from class jminusminus.JAST

compilationUnit, line

Constructor Summary

Constructors

Constructor and Description
JLogicalNotOp(int line, JExpression arg) Construct an AST for a logical NOT expression given its line number, and the operand.

Method Summary

Methods

Modifier and Type	Method and Description
JExpression	analyze(Context context) Analyzing a logical NOT operation means analyzing its operand, insuring it's a boolean, and setting the result to boolean.
void	codegen(CLEmitter output) Generate code for the case where we actually want a boolean value (true or false) computed onto the stack, eg for assignment to a boolean variable.
void	codegen(CLEmitter output, String targetLabel, boolean onTrue) The code generation necessary for branching simply flips the condition on which we branch.

Methods inherited from class jminusminus.JUnaryExpression

writeToStdOut

Methods inherited from class jminusminus.JExpression

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

JLogicalNotOp

public JLogicalNotOp(int line,
             JExpression arg)

Construct an AST for a logical NOT expression given its line number, and the operand.

Parameters:

line - line in which the logical NOT expression occurs in the source file.

arg - the operand.

Method Detail

analyze

public JExpression analyze(Context context)

Analyzing a logical NOT operation means analyzing its operand, insuring it's a boolean, and setting the result to boolean.

Specified by:

analyze in class JExpression

Parameters:

context - context in which names are resolved.

Returns:

the analyzed (and possibly rewritten) AST subtree.

codegen

public void codegen(CLEmitter output)

Generate code for the case where we actually want a boolean value (true or false) computed onto the stack, eg for assignment to a boolean variable.

Specified by:

codegen in class JAST

Parameters:

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

codegen

public void codegen(CLEmitter output,
           String targetLabel,
           boolean onTrue)

The code generation necessary for branching simply flips the condition on which we branch.

Overrides:

codegen in class JExpression

Parameters:

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

targetLabel - the label to which we should branch.

onTrue - do we branch on true?