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

java.lang.Object
  edu.mit.csail.sdg.alloy4compiler.ast.Browsable
      edu.mit.csail.sdg.alloy4compiler.ast.Expr
          edu.mit.csail.sdg.alloy4compiler.ast.ExprLet

public final class ExprLet
extends Expr

Immutable; represents an expression of the form (let a=b | x).

Invariant: type!=EMPTY => (var.type.unambiguos() && sub.mult==0)

Field Summary

Expr	expr The expression bound to the LET variable.
Expr	sub The body of the LET expression.
ExprVar	var The LET variable.

Fields inherited from class edu.mit.csail.sdg.alloy4compiler.ast.Expr

ambiguous, closingBracket, errors, mult, pos, weight

Method Summary

int	getDepth() Returns the height of the abstract syntax tree starting from this node.
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.
static Expr	make(Pos pos, ExprVar var, Expr expr, Expr sub) Constructs a LET expression.
Expr	resolve(Type p, java.util.Collection<ErrorWarning> warns) Resolves this expression if ambiguous.
Pos	span() Returns a Pos object representing the entire span of this Expr and all its subexpressions.
void	toString(java.lang.StringBuilder out, int indent) Print a textual description of it and all subnodes to a StringBuilder, with the given level of indentation.

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

and, any_arrow_lone, any_arrow_one, any_arrow_some, cardinality, cast2int, cast2sigint, closure, comprehensionOver, deNOP, div, domain, equal, equals, findAllFunctions, forAll, forLone, forNo, forOne, forSome, gt, gte, hashCode, hasVar, iff, iminus, implies, in, intersect, iplus, isSame, isSeq_arrow_lone, ite, join, lone_arrow_any, lone_arrow_lone, lone_arrow_one, lone_arrow_some, lone, loneOf, loneOf, lt, lte, minus, mul, mult, no, not, one_arrow_any, one_arrow_lone, one_arrow_one, one_arrow_some, one, oneOf, oneOf, or, override, plus, pos, product, range, reflexiveClosure, rem, resolve_as_formula, resolve_as_int, resolve_as_set, setOf, setOf, sha, shl, shr, some_arrow_any, some_arrow_lone, some_arrow_one, some_arrow_some, some, someOf, someOf, sumOver, toString, transpose, type, typecheck_as_formula, typecheck_as_int, typecheck_as_set

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

make, make, make, make, showAsTree

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

var

public final ExprVar var

The LET variable.

expr

public final Expr expr

The expression bound to the LET variable.

sub

public final Expr sub

The body of the LET expression.

Method Detail

span

public Pos span()

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

Overrides:

span in class Browsable

toString

public void toString(java.lang.StringBuilder out,
                     int indent)

Print a textual description of it and all subnodes to a StringBuilder, with the given level of indentation. (If indent<0, it will be printed in one line without line break)

Specified by:

toString in class Expr

make

public static Expr make(Pos pos,
                        ExprVar var,
                        Expr expr,
                        Expr sub)

Constructs a LET expression.

Parameters:

pos - - the position of the '=' token in the original Alloy model (or null if unknown)

var - - the LET variable

sub - - the body of the LET expression (which may or may not contain "var" as a free variable)

resolve

public Expr resolve(Type p,
                    java.util.Collection<ErrorWarning> warns)

Resolves this expression if ambiguous. (And if t.size()>0, it represents the set of tuples whose presence/absence is relevent to the parent expression) (Note: it's possible for t to be EMPTY, or even ambiguous!)

On success: the return value will be well-typed and unambiguous

On failure: the return value's "errors" list will be nonempty

If we detect any type warnings, we will add the type warnings to the "warnings" collection.

Specified by:

resolve in class Expr

warns - - the list that will receive any warning we generate; can be null if we wish to ignore warnings

getDepth

public int getDepth()

Returns the height of the abstract syntax tree starting from this node.

Specified by:

getDepth in class Expr

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