kiss-lang/tink_macro
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Make setter bypass in constructor optional.

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This commit is contained in:
back2dos
2013-10-13 19:42:07 +02:00
parent 516479cc72
commit ef7fe70446
2 changed files with 12 additions and 8 deletions
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8
README.md
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@@ -320,7 +320,7 @@ class Constructor {
function publish():Void; function publish():Void;
function addStatement(e:Expr, ?prepend = false):Void; function addStatement(e:Expr, ?prepend = false):Void;
function addArg(name:String, ?t:ComplexType, ?e:Expr, ?opt = false) function addArg(name:String, ?t:ComplexType, ?e:Expr, ?opt = false)
function init(name:String, pos:Position, with:FieldInit, ?prepend:Bool):Void; function init(name:String, pos:Position, with:FieldInit, ?options:{ ?prepend:Bool, ?bypass:Bool }):Void;
function onGenerate(hook:Expr->Expr):Void; function onGenerate(hook:Expr->Expr):Void;
} }
``` ```
@@ -347,16 +347,14 @@ To add a constructor argument, you can just use `addArg`.
### Field initialization ### Field initialization
The `init` method is the swiss army knife of initializing fields. The `prepend` parameter works the same as for `addStatement`. As for the rest, the behavior is somewhat magical. The `init` method is the swiss army knife of initializing fields. The `options.prepend` flag works the same as `prepend` for `addStatement`. As for `options.bypass`, the behavior is somewhat magical.
#### Setter bypass #### Setter bypass
It is important to know that when you initialize a field this way, existing setters will by bypassed. That's particularly helpful if your setter triggers a side effect that you don't want triggered. This is achieved by generating the assignment as `(untyped this).$name = $value`. To make the code typesafe again, this is prefixed with `if (false) { var __tmp = this.$name; __tmp = $value; }`. This code is later thrown out by the compiler. Its role is to ensure type safety without interfering with the normal typing order. It is important to know that when you initialize a field with `options.bypass` set to true, existing setters will by bypassed. That's particularly helpful if your setter triggers a side effect that you don't want triggered. This is achieved by generating the assignment as `(untyped this).$name = $value`. To make the code typesafe again, this is prefixed with `if (false) { var __tmp = this.$name; __tmp = $value; }`. This code is later thrown out by the compiler. Its role is to ensure type safety without interfering with the normal typing order.
Please do note, that the value will be in the generated code twice, therefore if it is an expression that calls a macro, the macro will be called twice. Please do note, that the value will be in the generated code twice, therefore if it is an expression that calls a macro, the macro will be called twice.
If you want to call the setter or avoid these tricks then use `addStatement` instead.
#### Initialization options #### Initialization options
The different options for initialization are as follows: The different options for initialization are as follows:

10
src/tink/macro/Constructor.hx
View File

@@ -66,7 +66,9 @@ class Constructor {
public function addArg(name:String, ?t:ComplexType, ?e:Expr, ?opt = false) public function addArg(name:String, ?t:ComplexType, ?e:Expr, ?opt = false)
args.push( { name : name, opt : opt || e != null, type : t, value: e } ); args.push( { name : name, opt : opt || e != null, type : t, value: e } );
public function init(name:String, pos:Position, with:FieldInit, ?prepend:Bool) { public function init(name:String, pos:Position, with:FieldInit, ?options:{ ?prepend:Bool, ?bypass:Bool }) {
if (options == null)
options = {};
var e = var e =
switch with { switch with {
case Arg(t, noPublish): case Arg(t, noPublish):
@@ -84,8 +86,12 @@ class Constructor {
var tmp = MacroApi.tempName(); var tmp = MacroApi.tempName();
if (options.bypass) {
addStatement(macro @:pos(pos) if (false) { var $tmp = this.$name; $i{tmp} = $e; }, true); addStatement(macro @:pos(pos) if (false) { var $tmp = this.$name; $i{tmp} = $e; }, true);
addStatement(macro @:pos(pos) (untyped this).$name = $e, prepend); addStatement(macro @:pos(pos) (untyped this).$name = $e, options.prepend);
}
else
addStatement(macro @:pos(pos) this.$name = $e, options.prepend);
} }
public inline function publish() public inline function publish()
if (isPublic == null) if (isPublic == null)