Index: docs/language/dartLangSpec.tex |
=================================================================== |
--- docs/language/dartLangSpec.tex (revision 33281) |
+++ docs/language/dartLangSpec.tex (working copy) |
@@ -3372,22 +3372,25 @@ |
Evaluation of an assignment $a$ of the form $v$ \code{=} $e$ proceeds as follows: |
-If there is neither a local variable declaration with name $v$ nor a setter declaration with name $v=$ in the lexical scope enclosing $a$, then: |
-\begin{itemize} |
- \item If $a$ occurs inside a top level or static function (be it function, method, getter, or setter) or variable initializer, evaluation of $a$ causes $e$ to be evaluated, after which a \code{NoSuchMethodError} is thrown. |
- \item Otherwise, the assignment is equivalent to the assignment \code{ \THIS{}.$v$ = $e$}. |
- \end{itemize} |
+%If there is neither a local variable declaration with name $v$ nor a setter declaration with name $v=$ in the lexical scope enclosing $a$, then: |
+%\begin{itemize} |
+% \item If $a$ occurs inside a top level or static function (be it function, method, getter, or setter) or variable initializer, evaluation of $a$ causes $e$ to be evaluated, after which a \code{NoSuchMethodError} is thrown. |
+% \item Otherwise, the assignment is equivalent to the assignment \code{ \THIS{}.$v$ = $e$}. |
+% \end{itemize} |
- Otherwise, let $d$ be the innermost declaration whose name is $v$, if it exists. |
+%Otherwise, |
-If $d$ is the declaration of a local variable, the expression $e$ is evaluated to an object $o$. Then, the variable $v$ is bound to $o$. |
-% unless $v$ is \FINAL{}, in which case a \code{NoSuchMethodError} is thrown (even if there is a noSuchMethod). |
-The value of the assignment expression is $o$. |
+Let $d$ be the innermost declaration whose name is $v$ or $v=$, if it exists. |
-If $d$ is the declaration of a library variable, the expression $e$ is evaluated to an object $o$. Then the setter $v=$ is invoked with its formal parameter bound to $o$. The value of the assignment expression is $o$. |
+If $d$ is the declaration of a local variable, the expression $e$ is evaluated to an object $o$. Then, the variable $v$ is bound to $o$ unless $v$ is \FINAL{} or \CONST{}, in which case a dynamic error occurs. |
+If no error occurs, the value of the assignment expression is $o$. |
-Otherwise, if $d$ is the declaration of a static variable in class $C$, then the assignment is equivalent to the assignment \code{$C.v$ = $e$}. |
+If $d$ is the declaration of a library variable, top level getter or top level setter, the expression $e$ is evaluated to an object $o$. Then the setter $v=$ is invoked with its formal parameter bound to $o$. The value of the assignment expression is $o$. |
+Otherwise, if $d$ is the declaration of a static variable, static getter or static setter in class $C$, then the assignment is equivalent to the assignment \code{$C.v$ = $e$}. |
+ |
+Otherwise, If $a$ occurs inside a top level or static function (be it function, method, getter, or setter) or variable initializer, evaluation of $a$ causes $e$ to be evaluated, after which a \code{NoSuchMethodError} is thrown. |
+ |
Otherwise, the assignment is equivalent to the assignment \code{ \THIS{}.$v$ = $e$}. |
In checked mode, it is a dynamic type error if $o$ is not \NULL{} and the interface of the class of $o$ is not a subtype of the actual type (\ref{actualTypeOfADeclaration}) of $v$. |
@@ -3927,7 +3930,8 @@ |
Evaluation of an identifier expression $e$ of the form $id$ proceeds as follows: |
-Let $d$ be the innermost declaration in the enclosing lexical scope whose name is $id$. If no such declaration exists in the lexical scope, let $d$ be the declaration of the inherited member named $id$ if it exists. |
+ |
+Let $d$ be the innermost declaration in the enclosing lexical scope whose name is $id$ or $id=$. If no such declaration exists in the lexical scope, let $d$ be the declaration of the inherited member named $id$ if it exists. |
%If no such member exists, let $d$ be the declaration of the static member name $id$ declared in a superclass of the current class, if it exists. |
\begin{itemize} |
@@ -3945,8 +3949,8 @@ |
\item If $d$ is a local variable or formal parameter then $e$ evaluates to the current binding of $id$. |
%\item If $d$ is a library variable, local variable, or formal parameter, then $e$ evaluates to the current binding of $id$. \commentary{This case also applies if d is a library or local function declaration, as these are equivalent to function-valued variable declarations.} |
\item If $d$ is a static method, top-level function or local function then $e$ evaluates to the function defined by $d$. |
-\item If $d$ is the declaration of a static variable or static getter declared in class $C$, then $e$ is equivalent to the getter invocation (\ref{getterInvocation}) $C.id$. |
-\item If $d$ is the declaration of a library variable or top-level getter, then $e$ is equivalent to the getter invocation $id$. |
+\item If $d$ is the declaration of a static variable, static getter or static setter declared in class $C$, then $e$ is equivalent to the getter invocation (\ref{getterInvocation}) $C.id$. |
+\item If $d$ is the declaration of a library variable, top-level getter or top-level setter, then $e$ is equivalent to the getter invocation $id$. |
\item Otherwise, if $e$ occurs inside a top level or static function (be it function, method, getter, or setter) or variable initializer, evaluation of $e$ causes a\code{NoSuchMethod} to be thrown. |
\item Otherwise, $e$ is equivalent to the property extraction (\ref{propertyExtraction}) \THIS{}.$id$. |
% This implies that referring to an undefined static getter by simple name is an error, whereas doing so by qualified name is only a warning. Same with assignments. Revise? |
@@ -3958,12 +3962,18 @@ |
\item If $d$ is a class, type alias or type parameter the static type of $e$ is \code{Type}. |
\item If $d$ is a local variable or formal parameter the static type of $e$ is the type of the variable $id$, unless $id$ is known to have some type $T$, in which case the static type of $e$ is $T$, provided that $T$ is more specific than any other type $S$ such that $v$ is known to have type $S$. |
\item If $d$ is a static method, top-level function or local function the static type of $e$ the function type defined by $d$. |
-\item If $d$ is the declaration of a static variable or static getter declared in class $C$, the static type of $e$ the static type of the getter invocation (\ref{getterInvocation}) $C.id$. |
+\item If $d$ is the declaration of a static variable or static getter declared in class $C$, the static type of $e$ the static type of the getter invocation (\ref{getterInvocation}) $C.id$. |
\item If $d$ is the declaration of a library variable or top-level getter, the static type of $e$ is the static type of the getter invocation $id$. |
\item Otherwise, if $e$ occurs inside a top level or static function (be it function, method, getter, or setter) or variable initializer, the static type of $e$ is \DYNAMIC{}. |
\item Otherwise, the static type of $e$ is the type of the property extraction (\ref{propertyExtraction}) \THIS{}.$id$. |
\end{itemize} |
+ \commentary{Note that if one declares a setter, we bind to the corresponding getter even if it does not exist.} |
+ |
+ \rationale{ |
+ This prevents situations where one uses uncorrelated setters and getters. The intent is to prevent errors when a getter in a surrounding scope is used accidentally. |
+ } |
+ |
It is a static warning if an identifier expression $id$ occurs inside a top level or static function (be it function, method, getter, or setter) or variable initializer and there is no declaration $d$ with name $id$ in the lexical scope enclosing the expression. |
\subsection{ Type Test} |
@@ -4833,7 +4843,7 @@ |
A Dart program consists of one or more libraries, and may be built out of one or more {\em compilation units}. A compilation unit may be a library or a part (\ref{parts}). |
-A library consists of (a possibly empty) set of imports, a set of exports, and a set of top-level declarations. A top-level declaration is either a class (\ref{classes}), a type alias declaration (\ref{typedef}), a function (\ref{functions}) or a variable declaration (\ref{variables}). The members of a library $L$ are those top level declarations given within a $L$. |
+A library consists of (a possibly empty) set of imports, a set of exports, and a set of top-level declarations. A top-level declaration is either a class (\ref{classes}), a type alias declaration (\ref{typedef}), a function (\ref{functions}) or a variable declaration (\ref{variables}). The members of a library $L$ are those top level declarations given within $L$. |
\begin{grammar} |
{\bf topLevelDefinition:}classDefinition; |