org.erights.e.elang.evm
Class AssignExpr

java.lang.Object
  |
  +--org.erights.e.elang.evm.ParseNode
        |
        +--org.erights.e.elang.evm.ENode
              |
              +--org.erights.e.elang.evm.EExpr
                    |
                    +--org.erights.e.elang.evm.AssignExpr

All Implemented Interfaces:

Cloneable, EPrintable, MatchMaker

public class AssignExpr

extends EExpr

Safe: BNF: varName ":=" eExpr

Changes the binding for 'varName' in the current environment to be the value of 'eExpr'. 'varName' must already be bound. Equivalent to

      (&varName) setValue(eExpr); eExpr

 

except that eExpr is only evaluated once. Therefore, the value returned is the value of eExpr, rather than the value stored in the slot (since setValue may do arbitrary coercions).

Author:

Mark S. Miller

Field Summary

private AtomicExpr	myNoun
private EExpr	myRValue

Fields inherited from class org.erights.e.elang.evm.ENode

Fields inherited from class org.erights.e.elang.evm.ParseNode

NUM_PR, PR_ASSIGN, PR_CALL, PR_COMP, PR_EEXPR, PR_LISTPATT, PR_ORDER, PR_PATTERN, PR_PRIM, PR_START

Constructor Summary

AssignExpr(SourceSpan optSpan, AtomicExpr noun, EExpr rValue)
Enabled:

Method Summary

protected StaticScope	computeStaticScope() When staticScope() is first requested on a given node, it calls computeStaticScope() to do the actual computation, which is then remembered.
boolean	matchBind(ConstList args, Object specimen, FlexList bindings) Enabled:
NounExpr	noun() Enabled:
Astro	qbuild(QuasiBuilder qbuilder) Enabled:
EExpr	rValue() Enabled:
protected Object	subEval(EvalContext ctx, boolean forValue) The recursive part that does the work
void	subPrintOn(TextWriter out, int priority) Enabled:
Object	welcome(ETreeVisitor visitor) Enabled:

Methods inherited from class org.erights.e.elang.evm.EExpr

__printOn, appendAllTo, appendTo, eval, eval, evalBool, printAsBlockOn, substitute, transform

Methods inherited from class org.erights.e.elang.evm.ENode

cleanCopy, copy, getOptPatternMap, getOptScopeMap, getPatternMap, getScopeMap, setPatternMap, setScopeMap, staticScope, synEnv

Methods inherited from class org.erights.e.elang.evm.ParseNode

asText, getOptSpan, lnPrintOn, lnPrintOn, matchBind, matchBind, matchBind, printListOn, toString

Methods inherited from class java.lang.Object

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

Field Detail

myNoun

private final AtomicExpr myNoun

myRValue

private final EExpr myRValue

Constructor Detail

AssignExpr

public AssignExpr(SourceSpan optSpan,
                  AtomicExpr noun,
                  EExpr rValue)

Enabled:

Method Detail

welcome

public Object welcome(ETreeVisitor visitor)

Enabled:

Specified by:

welcome in class ENode

qbuild

public Astro qbuild(QuasiBuilder qbuilder)

Enabled:

Overrides:

qbuild in class ENode

computeStaticScope

protected StaticScope computeStaticScope()

Description copied from class: ENode

When staticScope() is first requested on a given node, it calls computeStaticScope() to do the actual computation, which is then remembered.

Specified by:

computeStaticScope in class ENode

subEval

protected Object subEval(EvalContext ctx,
                         boolean forValue)

Description copied from class: EExpr

The recursive part that does the work

Specified by:

subEval in class EExpr

matchBind

public boolean matchBind(ConstList args,
                         Object specimen,
                         FlexList bindings)

Enabled:

Specified by:

matchBind in interface MatchMaker

Specified by:

matchBind in class ParseNode

noun

public NounExpr noun()

Enabled:

rValue

public EExpr rValue()

Enabled:

subPrintOn

public void subPrintOn(TextWriter out,
                       int priority)
                throws IOException

Enabled:

Specified by:

subPrintOn in class ParseNode

IOException