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Diffstat (limited to 'chapter17/README.md')
| -rw-r--r-- | chapter17/README.md | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/chapter17/README.md b/chapter17/README.md index d639962e..462a67f5 100644 --- a/chapter17/README.md +++ b/chapter17/README.md @@ -10,8 +10,6 @@ as `(arg--)-arg`. Also allows `s.fld++` and `ary[idx]++`, and their `--` variants. Allow pre-increment for identifiers only, for now: `--pc`. -`--ary[idx]` `ary[idx] -= 1` -`--expr.fld` ## Operator assignment @@ -50,25 +48,33 @@ immutable. Fields are always mutable during construction, but will become immutable at the end of either constructor. `int x; x=3; x++; // OK, primitive so mutable` + `int x =3; x++; // Ok, primitive so mutable, despite initializer` Assume in the next examples this struct exists: `struct S { int x; };` Then: + `S s; s = new S ; s.x++; // OK, no initializer so s.x is mutable` + `S s; s = new S{x=3}; s.x++; // OK, no initializer so s.x is mutable` + `S s = new S ; s.x++; // Error, initializer so s.x is immutable` + `S s = new S{x=3}; s.x++; // Error, initializer so s.x is immutable` Leading `!` makes mutable: + `S !s = new S; s.x++; // Ok, has '!' so mutable` 'var' is variable: + `var s = new S; s.x++; // Ok, has var so mutable` 'val' is a "value": not mutable through this reference, but may be mutable through other references. + `val s = new S; s.x++; // Error, val so s.x is immutable` @@ -128,7 +134,3 @@ for( int i=0; i<arg; i++ ) return i; // ERROR: Undefined name 'i' ``` - - -TODO -switch |