diff options
| -rw-r--r-- | doc/go_spec.txt | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/doc/go_spec.txt b/doc/go_spec.txt index 7f7b31c36..447cec6c4 100644 --- a/doc/go_spec.txt +++ b/doc/go_spec.txt @@ -54,7 +54,6 @@ Open issues: [ ] new(arraytype, n1, n2): spec only talks about length, not capacity (should only use new(arraytype, n) - this will allow later extension to multi-dim arrays w/o breaking the language) -[ ] comparison operators: can we compare interfaces? [ ] like to have assert() in the language, w/ option to disable code gen for it [ ] composite types should uniformly create an instance instead of a pointer [ ] semantics of statements @@ -85,6 +84,7 @@ Decisions in need of integration into the doc: Closed: +[x] comparison operators: can we compare interfaces? [x] can we add methods to types defined in another package? (probably not) [x] optional semicolons: too complicated and unclear [x] anonymous types are written using a type name, which can be a qualified identifier. @@ -1348,7 +1348,7 @@ number of methods with the same names, and corresponding (by name) methods have the same function types. Assignment compatibility: A value can be assigned to an interface variable -if the static type of the value implements the interface. +if the static type of the value implements the interface or if the value is "nil". Expressions @@ -1810,8 +1810,7 @@ Comparison operators Comparison operators yield a boolean result. All comparison operators apply to strings and numeric types. The operators "==" and "!=" also apply to -boolean values and to pointer types (including the value "nil"). Finally, -"==" and "!=" can also be used to compare interface types against "nil". +boolean values, pointer and interface types (including the value "nil"). == equal != not equal @@ -1822,7 +1821,9 @@ boolean values and to pointer types (including the value "nil"). Finally, Strings are compared byte-wise (lexically). -Interfaces can be tested against "nil" (§Interface types). +Pointers are equal if they point to the same value. + +Interfaces are equal if both their dynamic types and values are equal. For a value "v" of interface type, "v == nil" is true only if the predeclared constant "nil" is assigned explicitly to "v" (§Assignments), or "v" has not been modified since creation (§Program initialization and execution). |