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Adjusted initializer rules, changing a run-time error to compile-time.

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R=lrn@google.com

Review-Url: https://codereview.chromium.org/2843733002 .
This commit is contained in:
Erik Ernst 2017-05-19 14:22:34 +02:00
parent 6e0fd8ebb2
commit 3b5874a332
1 changed files with 9 additions and 3 deletions
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12
docs/language/dartLangSpec.tex
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@ -1413,7 +1413,14 @@ An initializer list begins with a colon, and consists of a comma-separated list
\end{grammar}
\LMHash{}
Let $k$ be a generative constructor. Then $k$ may include at most one superinitializer in its initializer list or a compile-time error occurs. If no superinitializer is provided, an implicit superinitializer of the form \SUPER{}() is added at the end of $k$'s initializer list, unless the enclosing class is class \code{Object}. It is a compile-time error if more than one initializer corresponding to a given instance variable appears in $k$'s initializer list. It is a compile-time error if $k$'s initializer list contains an initializer for a variable that is initialized by means of an initializing formal of $k$. % It is a compile-time error if $k$'s initializer list contains an initializer for a final variable $f$ whose declaration includes an initialization expression.
Let $k$ be a generative constructor.
Then $k$ may include at most one superinitializer in its initializer list or a compile-time error occurs.
If no superinitializer is provided, an implicit superinitializer of the form \SUPER{}() is added at the end of $k$'s initializer list,
unless the enclosing class is class \code{Object}.
It is a compile-time error if more than one initializer corresponding to a given instance variable appears in $k$'s initializer list.
It is a compile-time error if $k$'s initializer list contains an initializer for a variable that is initialized by means of an initializing formal of $k$.
It is a compile-time error if $k$'s initializer list contains an initializer for a final variable $f$ whose declaration includes an initialization expression.
It is a compile-time error if $k$ includes an initializing formal for a final variable $f$ whose declaration includes an initialization expression.
\LMHash{}
Each final instance variable $f$ declared in the immediately enclosing class must have an initializer in $k$'s initializer list unless it has already been initialized by one of the following means:
@ -1499,8 +1506,7 @@ proceeds as follows:
\LMHash{}
First, the expression $e$ is evaluated to an object $o$.
%%STRONG_MODE: The runtime error in the next sentence will be compile-time.
Then, the instance variable $v$ of $i$ is bound to $o$, unless $v$ is a final variable that has already been initialized, in which case a runtime error occurs.
Then, the instance variable $v$ of $i$ is bound to $o$.
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 of the instance variable $v$.
\LMHash{}