org.erights.e.elang.evm
Class IfExpr

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.IfExpr

All Implemented Interfaces:

Cloneable, EPrintable, MatchMaker

public class IfExpr

extends EExpr

Safe: BNF: "if" "(" cond-expr ")" "{" then-expr "}" "else" "{" else-expr "}"

Implements the "if" expression. If the cond-expr evaluates to true, the then-expr is evaluated in a child of the scope produced by the cond-expr. Otherwise, the else-expr is evaluated in a child of the outer scope.

Author:

Mark S. Miller

Field Summary

private EExpr	myElse
private EExpr	myTest
private EExpr	myThen

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

IfExpr(SourceSpan optSpan, EExpr test, EExpr then, EExpr els)
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.
EExpr	els() Enabled:
boolean	matchBind(ConstList args, Object specimen, FlexList bindings) Enabled:
protected Object	subEval(EvalContext ctx, boolean forValue) The recursive part that does the work
void	subPrintOn(TextWriter out, int priority) Enabled:
EExpr	test() Enabled:
EExpr	then() 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, qbuild, 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

myTest

private final EExpr myTest

myThen

private final EExpr myThen

myElse

private final EExpr myElse

Constructor Detail

IfExpr

public IfExpr(SourceSpan optSpan,
              EExpr test,
              EExpr then,
              EExpr els)

Enabled:

Method Detail

welcome

public Object welcome(ETreeVisitor visitor)

Enabled:

Specified by:

welcome 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

els

public EExpr els()

Enabled:

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

subPrintOn

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

Enabled:

Specified by:

subPrintOn in class ParseNode

IOException

test

public EExpr test()

Enabled:

then

public EExpr then()

Enabled: