Expression

java.lang.Object
- gnu.mapping.PropertySet
- - gnu.mapping.Procedure
  - - gnu.mapping.Procedure0
    - - gnu.expr.Expression

All Implemented Interfaces:

Named, Printable, javax.xml.transform.SourceLocator, org.xml.sax.Locator

Direct Known Subclasses:

AccessExp, ApplyExp, BeginExp, BlockExp, CaseExp, ErrorExp, ExitExp, IfExp, LangExp, QuoteExp, ScopeExp, SynchronizedExp, TryExp
```
public abstract class Expression
extends Procedure0
implements Printable, SourceLocator
```
Abstract class for syntactic forms that evaluate to a value. Scheme S-expressions get re-written to these before evaluation.

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`flags`
`protected static int`	`NEXT_AVAIL_FLAG`
`static Expression[]`	`noExpressions`
`protected Type`	`type`
`static int`	`VALIDATED`

Fields inherited from class gnu.mapping.Procedure
compilerKey, compilerXKey, validateApplyKey, validateXApplyKey

Fields inherited from class gnu.mapping.PropertySet
nameKey

Constructor Summary

Constructors
Constructor and Description

Expression()

Constructors
Constructor and Description
`Expression()`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`apply(CallContext ctx)` Evaluate the expression.
`java.lang.Object`	`apply0()`
`protected Type`	`calculateType()`
`Keyword`	`checkLiteralKeyword()` Is this a keyword argument? In the future this will return non-null only for explicit literal non-quoted Keywords.
`void`	`compile(Compilation comp, Declaration lhs)` Compile an expression with checking suitable for a known Declaration.
`abstract void`	`compile(Compilation comp, Target target)`
`void`	`compile(Compilation comp, Type type)`
`static void`	`compileButFirst(Expression exp, Compilation comp)` Compile all but the first sub-"statement".
`void`	`compileWithPosition(Compilation comp, Target target)` Same as compile, but emit line number beforehard.
`void`	`compileWithPosition(Compilation comp, Target target, Expression position)` Same as 2-argument compileWithPosition, but use some other Expression's line number.
`protected static Expression`	`deepCopy(Expression exp)`
`static Expression[]`	`deepCopy(Expression[] exps, IdentityHashTable mapper)`
`static Expression`	`deepCopy(Expression exp, IdentityHashTable mapper)` Make a deep copy of this expression, if possible.
`protected Expression`	`deepCopy(IdentityHashTable mapper)`
`java.lang.Object`	`eval(CallContext ctx)`
`java.lang.Object`	`eval(Environment env)`
`int`	`getColumnNumber()` Return current column number.
`java.lang.String`	`getFileName()` Normally same as getSystemId.
`boolean`	`getFlag(int flag)`
`int`	`getFlags()`
`int`	`getLineNumber()` Get the line number of (the start of) this Expression.
`java.lang.String`	`getPublicId()`
`java.lang.String`	`getSystemId()`
`Type`	`getType()` Return the Type used to represent the values of this Expression.
`Type`	`getTypeRaw()`
`boolean`	`isSingleValue()`
`boolean`	`isStableSourceLocation()` True if position is unlikely to change.
`static Expression`	`makeWhile(java.lang.Object cond, java.lang.Object body, Compilation parser)` Helper method to create a `while' statement.
`int`	`match0(CallContext ctx)` Pass zero arguments.
`Expression`	`maybeSetLine(Expression old)`
`protected abstract boolean`	`mustCompile()`
`boolean`	`neverReturns()` True if the expression provably never returns.
`void`	`print(Consumer out)`
`abstract void`	`print(gnu.kawa.io.OutPort ps)`
`void`	`printLineColumn(gnu.kawa.io.OutPort out)` Print line and column number if specified.
`void`	`setFile(java.lang.String filename)`
`void`	`setFlag(boolean setting, int flag)`
`void`	`setFlag(int flag)`
`void`	`setLine(Compilation comp)` Set line number from current position in `Compilation`.
`Expression`	`setLine(Expression old)`
`void`	`setLine(int lineno)`
`void`	`setLine(int lineno, int colno)`
`void`	`setLocation(SourceLocator location)` Copies the current location.
`void`	`setType(Type type)`
`boolean`	`side_effects()` True if evaluating may have side-effects.
`java.lang.String`	`toString()`
`Expression`	`validateApply(ApplyExp exp, InlineCalls visitor, Type required, Declaration decl)` Apply inlining transformations on a given ApplyExp.
`java.lang.Object`	`valueIfConstant()` Return value if it is constant, or null if non-constant or unknown.
`protected <R,D> R`	`visit(ExpVisitor<R,D> visitor, D d)`
`protected <R,D> void`	`visitChildren(ExpVisitor<R,D> visitor, D d)`

Methods inherited from class gnu.mapping.Procedure0
apply1, apply2, apply3, apply4, applyN, numArgs

Methods inherited from class gnu.mapping.Procedure
apply, check0, check1, check2, check3, check4, checkArgCount, checkN, getReturnType, getSetter, getSourceLocation, isSideEffectFree, match1, match2, match3, match4, matchN, maxArgs, maxArgs, minArgs, minArgs, set0, set1, setN, setSetter, setSourceLocation

Methods inherited from class gnu.mapping.PropertySet
getName, getProperty, getSymbol, removeProperty, setName, setProperty, setProperty, setSymbol

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - noExpressions
```
public static final Expression[] noExpressions
```
  - type
```
protected Type type
```
  - flags
```
protected int flags
```
  - VALIDATED
```
public static final int VALIDATED
```
    See Also:
    Constant Field Values
  - NEXT_AVAIL_FLAG
```
protected static final int NEXT_AVAIL_FLAG
```
    See Also:
    Constant Field Values
- Constructor Detail
  - Expression
```
public Expression()
```
- Method Detail
  - eval
```
public final java.lang.Object eval(CallContext ctx)
                            throws java.lang.Throwable
```
    Throws:
    
    java.lang.Throwable
  - eval
```
public final java.lang.Object eval(Environment env)
                            throws java.lang.Throwable
```
    Throws:
    
    java.lang.Throwable
  - mustCompile
```
protected abstract boolean mustCompile()
```
  - match0
```
public final int match0(CallContext ctx)
```
    Description copied from class: Procedure
    
    Pass zero arguments.
    
    Overrides:
    
    match0 in class Procedure
    
    Returns:
    non-negative if the match succeeded, else negative.
  - apply0
```
public final java.lang.Object apply0()
                              throws java.lang.Throwable
```
    Specified by:
    
    apply0 in class Procedure0
    
    Throws:
    
    java.lang.Throwable
  - apply
```
public void apply(CallContext ctx)
           throws java.lang.Throwable
```
    Evaluate the expression. This is named apply rather than eval so it is compatible with the full-tail-call calling convention, and we can stash an Expression in CallContext's proc field. FIXME - are we making use of this?
    
    Overrides:
    
    apply in class Procedure
    
    Throws:
    
    java.lang.Throwable
  - print
```
public final void print(Consumer out)
```
    Specified by:
    
    print in interface Printable
  - print
```
public abstract void print(gnu.kawa.io.OutPort ps)
```
  - printLineColumn
```
public void printLineColumn(gnu.kawa.io.OutPort out)
```
    Print line and column number if specified. This is a helper routineintended for use by print(OutPort).
  - compile
```
public abstract void compile(Compilation comp,
           Target target)
```
  - compileWithPosition
```
public final void compileWithPosition(Compilation comp,
                       Target target)
```
    Same as compile, but emit line number beforehard.
  - compileWithPosition
```
public final void compileWithPosition(Compilation comp,
                       Target target,
                       Expression position)
```
    Same as 2-argument compileWithPosition, but use some other Expression's line number.
  - compile
```
public final void compile(Compilation comp,
           Type type)
```
  - compile
```
public final void compile(Compilation comp,
           Declaration lhs)
```
    Compile an expression with checking suitable for a known Declaration. Leaves the result on the stack (i.e. does not assign to the lhs). It does coerce the value to a suitable type for the lhs, and throw a hopefully-informative WrongType exception on failure.
  - compileButFirst
```
public static void compileButFirst(Expression exp,
                   Compilation comp)
```
    Compile all but the first sub-"statement". A kludge used for constructor methods, since if the first "statement" is a super-constructor we need to inject initializer expressions.
  - deepCopy
```
public static Expression deepCopy(Expression exp,
                  IdentityHashTable mapper)
```
    Make a deep copy of this expression, if possible.
    
    Parameters:
    mapper - used to lookup parts (expressions, declarations) that have been translated in the parent. Needed for copied Declarations and BlockExps.
    
    Returns:
    a copy, or null if we can't copy.
  - deepCopy
```
public static Expression[] deepCopy(Expression[] exps,
                    IdentityHashTable mapper)
```
  - deepCopy
```
protected static Expression deepCopy(Expression exp)
```
  - deepCopy
```
protected Expression deepCopy(IdentityHashTable mapper)
```
  - visit
```
protected <R,D> R visit(ExpVisitor<R,D> visitor,
            D d)
```
  - visitChildren
```
protected <R,D> void visitChildren(ExpVisitor<R,D> visitor,
                       D d)
```
  - validateApply
```
public Expression validateApply(ApplyExp exp,
                       InlineCalls visitor,
                       Type required,
                       Declaration decl)
```
    Apply inlining transformations on a given ApplyExp. Assumes the ApplyExp's function is this expression, or can be optimized to this expression.
    
    Parameters:
    exp - an application whose function expression can be simplified to this expression.
    visitor - the context for the current inlining pass
    decl - if non-null, a Declaration bound to this expression.
    
    Returns:
    an Expression equivalent to the passed-in exp.
  - makeWhile
```
public static Expression makeWhile(java.lang.Object cond,
                   java.lang.Object body,
                   Compilation parser)
```
    Helper method to create a `while' statement.
  - setLocation
```
public final void setLocation(SourceLocator location)
```
    Copies the current location.
  - setLine
```
public final Expression setLine(Expression old)
```
  - maybeSetLine
```
public final Expression maybeSetLine(Expression old)
```
  - setFile
```
public final void setFile(java.lang.String filename)
```
  - setLine
```
public final void setLine(int lineno,
           int colno)
```
  - setLine
```
public final void setLine(int lineno)
```
  - getFileName
```
public final java.lang.String getFileName()
```
    Description copied from interface: SourceLocator
    
    Normally same as getSystemId.
  - setLine
```
public void setLine(Compilation comp)
```
    Set line number from current position in Compilation.
  - getPublicId
```
public java.lang.String getPublicId()
```
    Specified by:
    
    getPublicId in interface javax.xml.transform.SourceLocator
    
    Specified by:
    
    getPublicId in interface org.xml.sax.Locator
  - getSystemId
```
public java.lang.String getSystemId()
```
    Specified by:
    
    getSystemId in interface javax.xml.transform.SourceLocator
    
    Specified by:
    
    getSystemId in interface org.xml.sax.Locator
  - getLineNumber
```
public final int getLineNumber()
```
    Get the line number of (the start of) this Expression. The "first" line is line 1; unknown is -1.
    
    Specified by:
    
    getLineNumber in interface javax.xml.transform.SourceLocator
    
    Specified by:
    
    getLineNumber in interface org.xml.sax.Locator
  - getColumnNumber
```
public final int getColumnNumber()
```
    Description copied from interface: SourceLocator
    
    Return current column number. The "first" column is column 1; unknown is -1.
    
    Specified by:
    
    getColumnNumber in interface javax.xml.transform.SourceLocator
    
    Specified by:
    
    getColumnNumber in interface org.xml.sax.Locator
  - isStableSourceLocation
```
public boolean isStableSourceLocation()
```
    Description copied from interface: SourceLocator
    
    True if position is unlikely to change. True for an expression but not an input file.
  - getType
```
public final Type getType()
```
    Return the Type used to represent the values of this Expression.
  - calculateType
```
protected Type calculateType()
```
  - getTypeRaw
```
public final Type getTypeRaw()
```
  - setType
```
public void setType(Type type)
```
  - neverReturns
```
public boolean neverReturns()
```
    True if the expression provably never returns. Currently, this is very limited, not handling infinite recursion (tail- or otherwise), but better analysis is planned.
  - checkLiteralKeyword
```
public Keyword checkLiteralKeyword()
```
    Is this a keyword argument? In the future this will return non-null only for explicit literal non-quoted Keywords.
  - isSingleValue
```
public boolean isSingleValue()
```
  - valueIfConstant
```
public java.lang.Object valueIfConstant()
```
    Return value if it is constant, or null if non-constant or unknown.
  - setFlag
```
public void setFlag(boolean setting,
           int flag)
```
  - setFlag
```
public void setFlag(int flag)
```
  - getFlags
```
public int getFlags()
```
  - getFlag
```
public boolean getFlag(int flag)
```
  - side_effects
```
public boolean side_effects()
```
    True if evaluating may have side-effects.
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class Procedure

Class Expression

Field Summary

Fields inherited from class gnu.mapping.Procedure

Fields inherited from class gnu.mapping.PropertySet

Constructor Summary

Method Summary

Methods inherited from class gnu.mapping.Procedure0

Methods inherited from class gnu.mapping.Procedure

Methods inherited from class gnu.mapping.PropertySet

Methods inherited from class java.lang.Object

Field Detail

noExpressions

type

flags

VALIDATED

NEXT_AVAIL_FLAG

Constructor Detail

Expression

Method Detail

eval

eval

mustCompile

match0

apply0

apply

print

print

printLineColumn

compile

compileWithPosition

compileWithPosition

compile

compile

compileButFirst

deepCopy

deepCopy

deepCopy

deepCopy

visit

visitChildren

validateApply

makeWhile

setLocation

setLine

maybeSetLine

setFile

setLine

setLine

getFileName

setLine

getPublicId

getSystemId

getLineNumber

getColumnNumber

isStableSourceLocation

getType

calculateType

getTypeRaw

setType

neverReturns

checkLiteralKeyword

isSingleValue

valueIfConstant

setFlag

setFlag

getFlags

getFlag

side_effects

toString