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Diffstat (limited to 'doc/manual.rst')
| -rw-r--r-- | doc/manual.rst | 28 |
1 files changed, 12 insertions, 16 deletions
diff --git a/doc/manual.rst b/doc/manual.rst index 4eabd0225..2469a0525 100644 --- a/doc/manual.rst +++ b/doc/manual.rst @@ -7781,9 +7781,10 @@ More examples with custom pragmas: Macro pragmas ------------- -All macros and templates can also be used as pragmas. They can be attached -to routines (procs, iterators, etc), type names, or type expressions. The -compiler will perform the following simple syntactic transformations: +Macros and templates can sometimes be called with the pragma syntax. Cases +where this is possible include when attached to routine (procs, iterators, etc) +declarations or routine type expressions. The compiler will perform the +following simple syntactic transformations: .. code-block:: nim template command(name: string, def: untyped) = discard @@ -7810,20 +7811,15 @@ This is translated to: ------ -.. code-block:: nim - type - MyObject {.schema: "schema.protobuf".} = object - -This is translated to a call to the `schema` macro with a `nnkTypeDef` -AST node capturing both the left-hand side and right-hand side of the -definition. The macro can return a potentially modified `nnkTypeDef` tree -or multiple `nnkTypeDef` trees contained in a `nnkTypeSection` node -which will replace the original row in the type section. - -When multiple macro pragmas are applied to the same definition, the -compiler will apply them consequently from left to right. Each macro -will receive as input the output of the previous one. +When multiple macro pragmas are applied to the same definition, the first one +from left to right will be evaluated. This macro can then choose to keep +the remaining macro pragmas in its output, and those will be evaluated in +the same way. +There are a few more applications of macro pragmas, such as in type, +variable and constant declarations, but this behavior is considered to be +experimental and is documented in the `experimental manual +<manual_experimental.html#extended-macro-pragmas>` instead. Foreign function interface |