diff --git a/doc/manual.md b/doc/manual.md index 0e167be042024..db82d851b1625 100644 --- a/doc/manual.md +++ b/doc/manual.md @@ -6956,25 +6956,47 @@ All identifiers of a module are valid from the point of declaration until the end of the module. Identifiers from indirectly dependent modules are *not* available. The `system`:idx: module is automatically imported in every module. -If a module imports an identifier by two different modules, each occurrence of -the identifier has to be qualified unless it is an overloaded procedure or -iterator in which case the overloading resolution takes place: +If a module imports the same identifier from two different modules, the +identifier is considered ambiguous, which can be resolved in the following ways: + +* Qualifying the identifier as `module.identifier` resolves ambiguity + between modules. (See below for the case that the module name itself + is ambiguous.) +* Calling the identifier as a routine makes overload resolution take place, + which resolves ambiguity in the case that one overload matches stronger + than the others. +* Using the identifier in a context where the compiler can infer the type + of the identifier resolves ambiguity in the case that one definition + matches the type stronger than the others. ```nim # Module A var x*: string + proc foo*(a: string) = + echo "A: ", a ``` ```nim # Module B var x*: int + proc foo*(b: int) = + echo "B: ", b ``` ```nim # Module C import A, B + + foo("abc") # A: abc + foo(123) # B: 123 + let inferred: proc (x: string) = foo + foo("def") # A: def + write(stdout, x) # error: x is ambiguous write(stdout, A.x) # no error: qualifier used + + proc bar(a: int): int = a + 1 + assert bar(x) == x + 1 # no error: only A.x of type int matches var x = 4 write(stdout, x) # not ambiguous: uses the module C's x @@ -6998,7 +7020,7 @@ proc fb* = echo "buzz" import A/C import B/C -C.fb() # Error: ambiguous identifier: 'fb' +C.fb() # Error: ambiguous identifier: 'C' ``` diff --git a/tests/lookups/mambsym3.nim b/tests/lookups/mambsym3.nim new file mode 100644 index 0000000000000..946a5ff294960 --- /dev/null +++ b/tests/lookups/mambsym3.nim @@ -0,0 +1,4 @@ +# Module A +var x*: string +proc foo*(a: string) = + echo "A: ", a diff --git a/tests/lookups/mambsym4.nim b/tests/lookups/mambsym4.nim new file mode 100644 index 0000000000000..ed66cc16d9d1f --- /dev/null +++ b/tests/lookups/mambsym4.nim @@ -0,0 +1,4 @@ +# Module B +var x*: int +proc foo*(b: int) = + echo "B: ", b diff --git a/tests/lookups/tambsymmanual.nim b/tests/lookups/tambsymmanual.nim new file mode 100644 index 0000000000000..3ad91b8cc721d --- /dev/null +++ b/tests/lookups/tambsymmanual.nim @@ -0,0 +1,25 @@ +discard """ + output: ''' +A: abc +B: 123 +A: def +4 +''' +""" +# Module C +import mambsym3, mambsym4 + +foo("abc") # A: abc +foo(123) # B: 123 +let inferred: proc (x: string) = foo +foo("def") # A: def + +doAssert not compiles(write(stdout, x)) # error: x is ambiguous +write(stdout, mambsym3.x) # no error: qualifier used + +proc bar(a: int): int = a + 1 +doAssert bar(x) == x + 1 # no error: only A.x of type int matches + +var x = 4 +write(stdout, x) # not ambiguous: uses the module C's x +echo() # for test output