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Explicitly specify what happens when noSuchMethod(x) is not found

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R=lrn@google.com, regis@google.com

Review URL: https://codereview.chromium.org//389403002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@38212 260f80e4-7a28-3924-810f-c04153c831b5
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gbracha@google.com
2014-07-14 20:15:23 +00:00
parent 04702c37ed
commit 5dfa44d0a2
1 changed files with 57 additions and 6 deletions
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docs/language/dartLangSpec.tex
+57 -6
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@@ -3270,7 +3270,26 @@ If getter lookup has also failed, then a new instance $im$ of the predefined c
\item \code{im.namedArguments} evaluates to an immutable map with the same keys and values as \code{\{$x_{n+1}: o_{n+1}, \ldots, x_{n+k} : o_{n+k}$\}}.
\end{itemize}
Then the method \code{noSuchMethod()} is looked up in $o$ and invoked with argument $im$, and the result of this invocation is the result of evaluating $i$.
Then the method \code{noSuchMethod()} is looked up in $o$ and invoked with argument $im$, and the result of this invocation is the result of evaluating $i$. However, if the implementation found cannot be invoked with a single positional argument, the implementation of \code{noSuchMethod()} in class \code{Object} is invoked on $o$ with argument $im'$, where $im'$ is an instance of \code{Invocation} such that :
\begin{itemize}
\item \code{im.isMethod} evaluates to \code{\TRUE{}}.
\item \code{im.memberName} evaluates to \code{noSuchMethod'}.
\item \code{im.positionalArguments} evaluates to an immutable list whose sole element is $im$.
\item \code{im.namedArguments} evaluates to an empty immutable map.
\end{itemize}
and the result of the latter invocation is the result of evaluating $i$.
\rationale {
It is possible to bring about such a situation by overriding \code{noSuchMethod()} with the wrong number of arguments:}
\begin{code}
\CLASS{} Perverse \{
noSuchMethod(x,y) =$>$ x + y;
\}
\NEW{} Perverse.unknownMethod();
\end{code}
\commentary{Notice that the wording carefully avoids re-evaluating the receiver $o$ and the arguments $a_i$. }
@@ -3367,7 +3386,16 @@ If getter lookup has also failed, then a new instance $im$ of the predefined c
\item \code{im.positionalArguments} evaluates to an immutable list with the same values as \code{[$o_1, \ldots, o_n$]}.
\item \code{im.namedArguments} evaluates to an immutable map with the same keys and values as \code{\{$x_{n+1}: o_{n+1}, \ldots, x_{n+k} : o_{n+k}$\}}.
\end{itemize}
Then the method \code{noSuchMethod()} is looked up in $S$ and invoked on \THIS{} with argument $im$, and the result of this invocation is the result of evaluating $i$.
Then the method \code{noSuchMethod()} is looked up in $S$ and invoked on \THIS{} with argument $im$, and the result of this invocation is the result of evaluating $i$. However, if the implementation found cannot be invoked with a single positional argument, the implementation of \code{noSuchMethod()} in class \code{Object} is invoked on \THIS{} with argument $im'$, where $im'$ is an instance of \code{Invocation} such that :
\begin{itemize}
\item \code{im.isMethod} evaluates to \code{\TRUE{}}.
\item \code{im.memberName} evaluates to \code{noSuchMethod}.
\item \code{im.positionalArguments} evaluates to an immutable list whose sole element is $im$.
\item \code{im.namedArguments} evaluates to an empty immutable map.
\end{itemize}
and the result of this latter invocation is the result of evaluating $i$.
It is a compile-time error if a super method invocation occurs in a top-level function or variable initializer, in an instance variable initializer or initializer list, in class \code{Object}, in a factory constructor or in a static method or variable initializer.
@@ -3417,7 +3445,15 @@ If the getter lookup has failed, then a new instance $im$ of the predefined cla
\item \code{im.positionalArguments} evaluates to the value of \code{\CONST{} []}.
\item \code{im.namedArguments} evaluates to the value of \code{\CONST{} \{\}}.
\end{itemize}
Then the method \code{noSuchMethod()} is looked up in $o$ and invoked with argument $im$, and the result of this invocation is the result of evaluating $i$.
Then the method \code{noSuchMethod()} is looked up in $o$ and invoked with argument $im$, and the result of this invocation is the result of evaluating $i$. However, if the implementation found cannot be invoked with a single positional argument, the implementation of \code{noSuchMethod()} in class \code{Object} is invoked on $o$ with argument $im'$, where $im'$ is an instance of \code{Invocation} such that :
\begin{itemize}
\item \code{im.isMethod} evaluates to \code{\TRUE{}}.
\item \code{im.memberName} evaluates to \code{noSuchMethod}.
\item \code{im.positionalArguments} evaluates to an immutable list whose sole element is $im$.
\item \code{im.namedArguments} evaluates to an empty immutable map.
\end{itemize}
and the result of this latter invocation is the result of evaluating $i$.
Let $T$ be the static type of $e$. It is a static type warning if $T$ does not have a getter named $m$ unless $T$ or a superinterface of $T$ is annotated with an annotation denoting a constant identical to the constant \code{@proxy} defined in \code{dart:core}. The static type of $i$ is the declared return type of $T.m$, if $T.m$ exists; otherwise the static type of $i$ is \DYNAMIC{}.
@@ -3448,9 +3484,15 @@ If the getter lookup has failed, then a new instance $im$ of the predefined cla
\item \code{im.positionalArguments} evaluates to the value of \code{\CONST{} []}.
\item \code{im.namedArguments} evaluates to the value of \code{\CONST{} \{\}}.
\end{itemize}
Then the method \code{noSuchMethod()} is looked up in $S$ and invoked with argument $im$, and the result of this invocation is the result of evaluating $i$.
Then the method \code{noSuchMethod()} is looked up in $S$ and invoked with argument $im$, and the result of this invocation is the result of evaluating $i$. However, if the implementation found cannot be invoked with a single positional argument, the implementation of \code{noSuchMethod()} in class \code{Object} is invoked on \THIS{} with argument $im'$, where $im'$ is an instance of \code{Invocation} such that :
\begin{itemize}
\item \code{im.isMethod} evaluates to \code{\TRUE{}}.
\item \code{im.memberName} evaluates to \code{noSuchMethod}.
\item \code{im.positionalArguments} evaluates to an immutable list whose sole element is $im$.
\item \code{im.namedArguments} evaluates to an empty immutable map.
\end{itemize}
and the result of this latter invocation is the result of evaluating $i$.
It is a static type warning if $S$ does not have a getter named $m$. The static type of $i$ is the declared return type of $S.m$, if $S.m$ exists; otherwise the static type of $i$ is \DYNAMIC{}.
@@ -3534,7 +3576,16 @@ If the setter lookup has failed, then a new instance $im$ of the predefined cla
\item \code{im.namedArguments} evaluates to the value of \code{\CONST{} \{\}}.
\end{itemize}
Then the method \code{noSuchMethod()} is looked up in $o_1$ and invoked with argument $im$. The value of the assignment expression is $o_2$ irrespective of whether setter lookup has failed or succeeded.
Then the method \code{noSuchMethod()} is looked up in $o_1$ and invoked with argument $im$.
However, if the implementation found cannot be invoked with a single positional argument, the implementation of \code{noSuchMethod()} in class \code{Object} is invoked on $o_1$ with argument $im'$, where $im'$ is an instance of \code{Invocation} such that :
\begin{itemize}
\item \code{im.isMethod} evaluates to \code{\TRUE{}}.
\item \code{im.memberName} evaluates to \code{noSuchMethod}.
\item \code{im.positionalArguments} evaluates to an immutable list whose sole element is $im$.
\item \code{im.namedArguments} evaluates to an empty immutable map.
\end{itemize}
The value of the assignment expression is $o_2$ irrespective of whether setter lookup has failed or succeeded.
Evaluation of an assignment of the form $p.v \code{=} e$, where $p$ is a deferred prefix, proceeds as follows: