edu.mit.csail.sdg.alloy4compiler.ast
Class Func

java.lang.Object
  edu.mit.csail.sdg.alloy4compiler.ast.Browsable
      edu.mit.csail.sdg.alloy4compiler.ast.Func

public final class Func
extends Browsable

Mutable; represents a predicate or function.

Invariant: the list of parameters do not contain duplicates

Invariant: none of the parameter declaration contains a predicate/function call

Invariant: the return type declaration does not contain a predicate/function call

Field Summary

ConstList<Decl>	decls The list of parameter declarations; may be an empty list if this predicate/function has no parameters.
boolean	isPred True if this is a predicate; false if this is a function.
Pos	isPrivate If nonnull, then this predicate/function is private (and this.isPrivate is the location of the "private" keyword)
java.lang.String	label The label of this predicate/function; it does not need to be unique.
Pos	pos The location in the original file where this predicate/function is declared; never null.
Expr	returnDecl The declared return type; never null.

Constructor Summary

Func(Pos pos, Pos isPrivate, java.lang.String label, java.util.List<Decl> decls, Expr returnDecl, Expr body)
Constructs a new predicate/function.

Func(Pos pos, java.lang.String label, java.util.List<Decl> decls, Expr returnDecl, Expr body)
Constructs a new predicate/function.

Method Summary

Expr	call(Expr... args) Convenience method that calls this function with the given list of arguments.
int	count() Return the number of parameters.
ExprVar	get(int i) Return the i-th parameter where i goes from 0 to count()-1
Expr	getBody() Return the body of this predicate/function.
java.lang.String	getHTML() Returns the description (as HTML) to show for this node.
java.util.List<? extends Browsable>	getSubnodes() Returns a list of subnodes for this node.
java.util.List<ExprVar>	params() Return the list of all parameters.
Pos	pos() Returns a Pos object representing the position of this Expr.
void	setBody(Expr newBody) Changes the method body.
Pos	span() Returns a Pos object representing the entire span of this Expr and all its subexpressions.
java.lang.String	toString() Returns a human-readable description for this predicate/function

Methods inherited from class edu.mit.csail.sdg.alloy4compiler.ast.Browsable

make, make, make, make, showAsTree

Methods inherited from class java.lang.Object

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

Field Detail

pos

public final Pos pos

The location in the original file where this predicate/function is declared; never null.

isPrivate

public final Pos isPrivate

If nonnull, then this predicate/function is private (and this.isPrivate is the location of the "private" keyword)

label

public final java.lang.String label

The label of this predicate/function; it does not need to be unique.

isPred

public final boolean isPred

True if this is a predicate; false if this is a function.

decls

public final ConstList<Decl> decls

The list of parameter declarations; may be an empty list if this predicate/function has no parameters.

returnDecl

public final Expr returnDecl

The declared return type; never null.

Constructor Detail

Func

public Func(Pos pos,
            java.lang.String label,
            java.util.List<Decl> decls,
            Expr returnDecl,
            Expr body)
     throws Err

Constructs a new predicate/function.

The first declaration's bound should be an expression with no free variables.
The second declaration's bound should be an expression with no free variables, except possibly the parameters in first declaration.
The third declaration's bound should be an expression with no free variables, except possibly the parameters in first two declarations.
etc.
The return declaration should have no free variables, except possibly the list of input parameters.

Parameters:

pos - - the original position in the file

label - - the label for this predicate/function (does not have to be unique)

decls - - the list of parameter declarations (can be null or an empty list if this predicate/function has no parameters)

returnDecl - - the return declaration (null if this is a predicate rather than a function)

Throws:

ErrorType - if returnType!=null and returnType cannot be unambiguously typechecked to be a set/relation

ErrorSyntax - if the list of parameters contain duplicates

ErrorSyntax - if at least one of the parameter declaration contains a predicate/function call

ErrorSyntax - if this function's return type declaration contains a predicate/function call

Err

Func

public Func(Pos pos,
            Pos isPrivate,
            java.lang.String label,
            java.util.List<Decl> decls,
            Expr returnDecl,
            Expr body)
     throws Err

Constructs a new predicate/function.

The first declaration's bound should be an expression with no free variables.
The second declaration's bound should be an expression with no free variables, except possibly the parameters in first declaration.
The third declaration's bound should be an expression with no free variables, except possibly the parameters in first two declarations.
etc.
The return declaration should have no free variables, except possibly the list of input parameters.

Parameters:

pos - - the original position in the file

isPrivate - - if nonnull, then the user intended this func/pred to be "private"

label - - the label for this predicate/function (does not have to be unique)

decls - - the list of parameter declarations (can be null or an empty list if this predicate/function has no parameters)

returnDecl - - the return declaration (null if this is a predicate rather than a function)

Throws:

ErrorType - if returnType!=null and returnType cannot be unambiguously typechecked to be a set/relation

ErrorSyntax - if the list of parameters contain duplicates

ErrorSyntax - if at least one of the parameter declaration contains a predicate/function call

ErrorSyntax - if this function's return type declaration contains a predicate/function call

Err

Method Detail

count

public int count()

Return the number of parameters.

get

public ExprVar get(int i)

Return the i-th parameter where i goes from 0 to count()-1

params

public java.util.List<ExprVar> params()

Return the list of all parameters.

setBody

public void setBody(Expr newBody)
             throws Err

Changes the method body. Precondition: The expression should have no free variables, except possibly the list of function parameters.

Throws:

ErrorSyntax - if newBody.mult!=0

ErrorType - if newBody cannot be unambiguously resolved

ErrorType - if newBody's type is incompatible with the original declared type of this predicate/function

Err

getBody

public Expr getBody()

Return the body of this predicate/function.
If the user has not called setBody() to set the body,
then the default body is "false" (if this is a predicate),
or the empty set/relation of the appropriate arity (if this is a function).

call

public Expr call(Expr... args)

Convenience method that calls this function with the given list of arguments.

toString

public final java.lang.String toString()

Returns a human-readable description for this predicate/function

Overrides:

toString in class java.lang.Object

pos

public final Pos pos()

Returns a Pos object representing the position of this Expr.

Overrides:

pos in class Browsable

span

public final Pos span()

Returns a Pos object representing the entire span of this Expr and all its subexpressions.

Overrides:

span in class Browsable

getHTML

public java.lang.String getHTML()

Returns the description (as HTML) to show for this node.

Specified by:

getHTML in class Browsable

getSubnodes

public java.util.List<? extends Browsable> getSubnodes()

Returns a list of subnodes for this node.

Specified by:

getSubnodes in class Browsable