-Yrangepos 除了在宏中提供源位置外还有什么作用
What's the effect of -Yrangepos other than giving me source locations in macros
所以我用谷歌搜索了一下，但除了稀疏之外没有其他信息：
-Yrangepos Use range positions for syntax trees.
好的。我知道如果我想在宏中捕获源代码片段，我需要使用它。
现在我的两个问题是：
- 为什么默认情况下不启用？
- 使用它是否有任何副作用（例如增加 class 文件大小）？
出于性能原因，我只能猜测 scalac 默认情况下不使用范围位置。
在常规编译中，位置仅用于错误报告和将行号信息保存到类文件中。偏移位置足以做到这一点，因此没有必要完成操纵范围位置所需的所有工作。
除了简单的编译速度之外，我认为范围位置不会产生任何其他成本。
makro 拼写为 Burmak(r)o 的问题 introducing -Yrangepos 是由您的用例引起的。
-X 选项表示永久性，而 -Y 可能随时消失，这意味着它可能成为默认行为。
也许不是因为 bugs and crashes.
在a team meeting written up by Moors：
Range positions [martin]
Respecting range positions - decay in the ide which has to do with the
fact that transformations in the typer or parser don’t respect range
positions
- every checked in change - automatically check range positions
- range positions = not just a position point but start and end, contained in tree nodes (RangePosition is a subclass of Position)
- there is map of RangePositions in CompilationUnit
invariants:
- range positions of child nodes are contained in range pos of parent nodes
- no overlap (except for transparent range positions)
- rangepos cover whole program
problems:
- templates
- for
check files contain positions
rangeposition(start,point,end).focus == offsetposition(point) //
escape from non-overlap invariant
2012年-Yrangepos的PR验证频繁失败；它已修复，但 turned into a nightly validation 以减少资源。
A few things about rangepos:
- if you try to run any code with 'scalac -Ybrowse:typer -Yrangepos FILE.scala' you will see that most of the trees have range positions.
- some don't, yes, that's a bit unfortunate but we are trying to improve on that - actually whenever you find such in Yrangepos mode it
is possible that it is a bug. The situation has improved dramatically
from
2.9 to 2.10.0-snapshots.
- syntactic trees are often assigned offset positions (this is something you might be experiencing but I would have to see an
example)
- for the compiler we only care if range positions are valid up to (and including) typer. after that, we don't care. You are running your
tool after refchecks from what I can see, this can interfere with a
couple of transformations that happen in refchecks which can
manipulate/assign range- or offset- positions.
切换到范围位置似乎很容易，因为基础数学，但在合成或重构树时分配位置仍然存在错误like this one that demonstrate the extra labor involved。
虽然演示编译器需要范围位置，但它们不在批编译的关键路径中。有了更多资源来提高稳健性，也许他们可以翻转开关。
所以我用谷歌搜索了一下，但除了稀疏之外没有其他信息：
-Yrangepos Use range positions for syntax trees.
好的。我知道如果我想在宏中捕获源代码片段，我需要使用它。
现在我的两个问题是：
- 为什么默认情况下不启用？
- 使用它是否有任何副作用（例如增加 class 文件大小）？
出于性能原因，我只能猜测 scalac 默认情况下不使用范围位置。
在常规编译中，位置仅用于错误报告和将行号信息保存到类文件中。偏移位置足以做到这一点，因此没有必要完成操纵范围位置所需的所有工作。
除了简单的编译速度之外，我认为范围位置不会产生任何其他成本。
makro 拼写为 Burmak(r)o 的问题 introducing -Yrangepos 是由您的用例引起的。
-X 选项表示永久性，而 -Y 可能随时消失，这意味着它可能成为默认行为。
也许不是因为 bugs and crashes.
在a team meeting written up by Moors：
Range positions [martin]
Respecting range positions - decay in the ide which has to do with the fact that transformations in the typer or parser don’t respect range positions
- every checked in change - automatically check range positions
- range positions = not just a position point but start and end, contained in tree nodes (RangePosition is a subclass of Position)
- there is map of RangePositions in CompilationUnit
invariants:
- range positions of child nodes are contained in range pos of parent nodes
- no overlap (except for transparent range positions)
- rangepos cover whole program
problems:
- templates
- for
check files contain positions
rangeposition(start,point,end).focus == offsetposition(point) // escape from non-overlap invariant
2012年-Yrangepos的PR验证频繁失败；它已修复，但 turned into a nightly validation 以减少资源。
A few things about rangepos:
- if you try to run any code with 'scalac -Ybrowse:typer -Yrangepos FILE.scala' you will see that most of the trees have range positions.
- some don't, yes, that's a bit unfortunate but we are trying to improve on that - actually whenever you find such in Yrangepos mode it is possible that it is a bug. The situation has improved dramatically from 2.9 to 2.10.0-snapshots.
- syntactic trees are often assigned offset positions (this is something you might be experiencing but I would have to see an example)
- for the compiler we only care if range positions are valid up to (and including) typer. after that, we don't care. You are running your tool after refchecks from what I can see, this can interfere with a couple of transformations that happen in refchecks which can manipulate/assign range- or offset- positions.
切换到范围位置似乎很容易，因为基础数学，但在合成或重构树时分配位置仍然存在错误like this one that demonstrate the extra labor involved。
虽然演示编译器需要范围位置，但它们不在批编译的关键路径中。有了更多资源来提高稳健性，也许他们可以翻转开关。