mirror of
https://github.com/nim-lang/Nim.git
synced 2025-12-30 01:44:37 +00:00
Merge pull request #2954 from avsej/fix-rest-syntax-in-astspec
Fix rest syntax in astspec
This commit is contained in:
Andreas Rumpf
118
doc/astspec.txt
118
doc/astspec.txt
@@ -40,16 +40,16 @@ For the ``NimNode`` type, the ``[]`` operator has been overloaded:
|
||||
``n[i]`` is ``n``'s ``i``-th child.
|
||||
|
||||
To specify the AST for the different Nim constructs, the notation
|
||||
``nodekind(son1, son2, ...)`` or ``nodekind(value)`` or
|
||||
``nodekind(son1, son2, ...)`` or ``nodekind(value)`` or
|
||||
``nodekind(field=value)`` is used.
|
||||
|
||||
Some child may be missing. A missing child is a node of kind ``nnkEmpty``;
|
||||
Some child may be missing. A missing child is a node of kind ``nnkEmpty``;
|
||||
a child can never be nil.
|
||||
|
||||
|
||||
Leaf nodes/Atoms
|
||||
================
|
||||
A leaf of the AST often corresponds to a terminal symbol in the concrete
|
||||
A leaf of the AST often corresponds to a terminal symbol in the concrete
|
||||
syntax.
|
||||
|
||||
----------------- ---------------------------------------------
|
||||
@@ -95,8 +95,8 @@ AST:
|
||||
|
||||
.. code-block:: nim
|
||||
nnkCommand(
|
||||
nnkIdent(!"echo"),
|
||||
nnkStrLit("abc"),
|
||||
nnkIdent(!"echo"),
|
||||
nnkStrLit("abc"),
|
||||
nnkStrLit("xyz")
|
||||
)
|
||||
|
||||
@@ -113,8 +113,8 @@ AST:
|
||||
|
||||
.. code-block:: nim
|
||||
nnkCall(
|
||||
nnkIdent(!"echo"),
|
||||
nnkStrLit("abc"),
|
||||
nnkIdent(!"echo"),
|
||||
nnkStrLit("abc"),
|
||||
nnkStrLit("xyz")
|
||||
)
|
||||
|
||||
@@ -131,12 +131,12 @@ AST:
|
||||
|
||||
.. code-block:: nim
|
||||
nnkInfix(
|
||||
nnkIdent(!"&"),
|
||||
nnkStrLit("abc"),
|
||||
nnkIdent(!"&"),
|
||||
nnkStrLit("abc"),
|
||||
nnkStrLit("xyz")
|
||||
)
|
||||
|
||||
Note that with multiple infix operators, the command is parsed by operator
|
||||
Note that with multiple infix operators, the command is parsed by operator
|
||||
precedence.
|
||||
|
||||
Concrete syntax:
|
||||
@@ -148,18 +148,18 @@ AST:
|
||||
|
||||
.. code-block:: nim
|
||||
nnkInfix(
|
||||
nnkIdent(!"+"),
|
||||
nnkIdent(!"+"),
|
||||
nnkIntLit(5),
|
||||
nnkInfix(
|
||||
nnkIdent(!"*"),
|
||||
nnkIntLit(3),
|
||||
nnkIdent(!"*"),
|
||||
nnkIntLit(3),
|
||||
nnkIntLit(4)
|
||||
)
|
||||
)
|
||||
|
||||
As a side note, if you choose to use infix operators in a prefix form, the AST
|
||||
behaves as a
|
||||
[parenthetical function call](./macros.html#calls-expressions-call-with) with
|
||||
As a side note, if you choose to use infix operators in a prefix form, the AST
|
||||
behaves as a
|
||||
[parenthetical function call](./macros.html#calls-expressions-call-with) with
|
||||
``nnkAccQuoted``, as follows:
|
||||
|
||||
Concrete syntax:
|
||||
@@ -173,8 +173,8 @@ AST:
|
||||
nnkCall(
|
||||
nnkAccQuoted(
|
||||
nnkIdent(!"+")
|
||||
),
|
||||
nnkIntLit(3),
|
||||
),
|
||||
nnkIntLit(3),
|
||||
nnkIntLit(4)
|
||||
)
|
||||
|
||||
@@ -190,7 +190,7 @@ AST:
|
||||
|
||||
.. code-block:: nim
|
||||
nnkPrefix(
|
||||
nnkIdent(!"?"),
|
||||
nnkIdent(!"?"),
|
||||
nnkStrLit("abc")
|
||||
)
|
||||
|
||||
@@ -198,7 +198,7 @@ AST:
|
||||
Postfix operator call
|
||||
---------------------
|
||||
|
||||
**Note:** There are no postfix operators in Nim. However, the
|
||||
**Note:** There are no postfix operators in Nim. However, the
|
||||
``nnkPostfix`` node is used for the *asterisk export marker* ``*``:
|
||||
|
||||
Concrete syntax:
|
||||
@@ -210,7 +210,7 @@ AST:
|
||||
|
||||
.. code-block:: nim
|
||||
nnkPostfix(
|
||||
nnkIdent(!"*"),
|
||||
nnkIdent(!"*"),
|
||||
nnkIdent(!"identifier")
|
||||
)
|
||||
|
||||
@@ -227,11 +227,11 @@ AST:
|
||||
|
||||
.. code-block:: nim
|
||||
nnkCall(
|
||||
nnkIdent(!"writeln"),
|
||||
nnkIdent(!"writeln"),
|
||||
nnkExprEqExpr(
|
||||
nnkIdent(!"file"),
|
||||
nnkIdent(!"file"),
|
||||
nnkIdent(!"stdout")
|
||||
),
|
||||
),
|
||||
nnkStrLit("hallo")
|
||||
)
|
||||
|
||||
@@ -310,7 +310,7 @@ AST:
|
||||
.. code-block:: nim
|
||||
nnkDotExpr(nnkIdent(!"x"), nnkIdent(!"y"))
|
||||
|
||||
If you use Nim's flexible calling syntax (as in ``x.len()``), the result is the
|
||||
If you use Nim's flexible calling syntax (as in ``x.len()``), the result is the
|
||||
same as above but wrapped in an ``nnkCall``.
|
||||
|
||||
|
||||
@@ -331,7 +331,7 @@ AST:
|
||||
Parentheses
|
||||
-----------
|
||||
|
||||
Parentheses for affecting operator precedence or tuple construction
|
||||
Parentheses for affecting operator precedence or tuple construction
|
||||
are built with the ``nnkPar`` node.
|
||||
|
||||
Concrete syntax:
|
||||
@@ -343,12 +343,12 @@ AST:
|
||||
|
||||
.. code-block:: nim
|
||||
nnkPar(nnkIntLit(1), nnkIntLit(2), nnkPar(nnkIntLit(3)))
|
||||
|
||||
|
||||
|
||||
|
||||
Curly braces
|
||||
------------
|
||||
|
||||
Curly braces are used as the set constructor.
|
||||
Curly braces are used as the set constructor.
|
||||
|
||||
Concrete syntax:
|
||||
|
||||
@@ -379,7 +379,7 @@ AST:
|
||||
Brackets
|
||||
--------
|
||||
|
||||
Brackets are used as the array constructor.
|
||||
Brackets are used as the array constructor.
|
||||
|
||||
Concrete syntax:
|
||||
|
||||
@@ -430,8 +430,8 @@ AST:
|
||||
Documentation Comments
|
||||
----------------------
|
||||
|
||||
Double-hash (``##``) comments in the code actually have their own format,
|
||||
but the comments do not yet show up in the AST, which will only show that
|
||||
Double-hash (``##``) comments in the code actually have their own format,
|
||||
but the comments do not yet show up in the AST, which will only show that
|
||||
a comment exists, not what it contains. Single-hash (``#``) comments are ignored.
|
||||
|
||||
Concrete syntax:
|
||||
@@ -447,14 +447,14 @@ AST:
|
||||
.. code-block:: nim
|
||||
nnkCommentStmt() # only appears once for the first two lines!
|
||||
stmt1
|
||||
nnkCommentStmt() # another nnkCommentStmt because there is another comment
|
||||
nnkCommentStmt() # another nnkCommentStmt because there is another comment
|
||||
# (separate from the first)
|
||||
|
||||
Pragmas
|
||||
-------
|
||||
|
||||
One of Nim's cool features is pragmas, which allow fine-tuning of various
|
||||
aspects of the language. They come in all types, such as adorning procs and
|
||||
aspects of the language. They come in all types, such as adorning procs and
|
||||
objects, but the standalone ``emit`` pragma shows the basics with the AST.
|
||||
|
||||
Concrete syntax:
|
||||
@@ -503,7 +503,7 @@ there is no ``else`` branch, no ``nnkElse`` child exists.
|
||||
Concrete syntax:
|
||||
|
||||
.. code-block:: nim
|
||||
if cond1:
|
||||
if cond1:
|
||||
stmt1
|
||||
elif cond2:
|
||||
stmt2
|
||||
@@ -560,7 +560,7 @@ AST:
|
||||
.. code-block:: nim
|
||||
nnkStmtList(stmt1, stmt2, stmt3)
|
||||
|
||||
|
||||
|
||||
Case statement
|
||||
--------------
|
||||
|
||||
@@ -568,7 +568,7 @@ Concrete syntax:
|
||||
|
||||
.. code-block:: nim
|
||||
case expr1
|
||||
of expr2, expr3..expr4:
|
||||
of expr2, expr3..expr4:
|
||||
stmt1
|
||||
of expr5:
|
||||
stmt2
|
||||
@@ -629,11 +629,11 @@ Concrete syntax:
|
||||
.. code-block:: nim
|
||||
try:
|
||||
stmt1
|
||||
except e1, e2:
|
||||
except e1, e2:
|
||||
stmt2
|
||||
except e3:
|
||||
stmt3
|
||||
except:
|
||||
except:
|
||||
stmt4
|
||||
finally:
|
||||
stmt5
|
||||
@@ -642,9 +642,9 @@ AST:
|
||||
|
||||
.. code-block:: nim
|
||||
nnkTryStmt(
|
||||
stmt1,
|
||||
nnkExceptBranch(e1, e2, stmt2),
|
||||
nnkExceptBranch(e3, stmt3),
|
||||
stmt1,
|
||||
nnkExceptBranch(e1, e2, stmt2),
|
||||
nnkExceptBranch(e3, stmt3),
|
||||
nnkExceptBranch(stmt4),
|
||||
nnkFinally(stmt5)
|
||||
)
|
||||
@@ -875,8 +875,8 @@ Note that either the second or third (or both) parameters above must exist,
|
||||
as the compiler needs to know the type somehow (which it can infer from
|
||||
the given assignment).
|
||||
|
||||
This is not the same AST for all uses of ``var``. See
|
||||
[Procedure declaration](http://nim-lang.org/docs/macros.html#statements-procedure-declaration)
|
||||
This is not the same AST for all uses of ``var``. See
|
||||
[Procedure declaration](http://nim-lang.org/docs/macros.html#statements-procedure-declaration)
|
||||
for details.
|
||||
|
||||
Let section
|
||||
@@ -921,7 +921,7 @@ AST:
|
||||
Type section
|
||||
------------
|
||||
|
||||
Starting with the simplest case, a ``type`` section appears much like ``var``
|
||||
Starting with the simplest case, a ``type`` section appears much like ``var``
|
||||
and ``const``.
|
||||
|
||||
Concrete syntax:
|
||||
@@ -976,7 +976,7 @@ AST:
|
||||
nnkGenericParams(
|
||||
nnkIdentDefs(
|
||||
nnkIdent(!"T"),
|
||||
nnkEmpty(), # if the type is declared with options, like
|
||||
nnkEmpty(), # if the type is declared with options, like
|
||||
# ``[T: SomeInteger]``, they are given here
|
||||
nnkEmpty(),
|
||||
)
|
||||
@@ -1113,7 +1113,7 @@ AST:
|
||||
# ...
|
||||
)
|
||||
|
||||
Static types, like ``static[int]``, use ``nnkIdent`` wrapped in
|
||||
Static types, like ``static[int]``, use ``nnkIdent`` wrapped in
|
||||
``nnkStaticTy``.
|
||||
|
||||
Concrete syntax:
|
||||
@@ -1153,7 +1153,7 @@ Nim type Corresponding AST
|
||||
``iterator`` ``nnkIteratorTy``
|
||||
``object`` ``nnkObjectTy``
|
||||
|
||||
Take special care when declaring types as ``proc``s. The behavior is similar
|
||||
Take special care when declaring types as ``proc``. The behavior is similar
|
||||
to ``Procedure declaration``, below, but does not treat ``nnkGenericParams``.
|
||||
Generic parameters are treated in the type, not the ``proc`` itself.
|
||||
|
||||
@@ -1178,8 +1178,8 @@ AST:
|
||||
)
|
||||
)
|
||||
|
||||
The same syntax applies to ``iterator``s (with ``nnkIteratorTy``), but
|
||||
*does not* apply to ``converter``s or ``template``s.
|
||||
The same syntax applies to ``iterator`` (with ``nnkIteratorTy``), but
|
||||
*does not* apply to ``converter`` or ``template``.
|
||||
|
||||
Mixin statement
|
||||
---------------
|
||||
@@ -1232,13 +1232,13 @@ AST:
|
||||
nnkFormalParams(
|
||||
nnkIdent(!"int"), # the first FormalParam is the return type. nnkEmpty() if there is none
|
||||
nnkIdentDefs(
|
||||
nnkIdent(!"x"),
|
||||
nnkIdent(!"x"),
|
||||
nnkIdent(!"int"), # type type (required for procs, not for templates)
|
||||
nnkIntLit(3) # a default value
|
||||
),
|
||||
nnkIdentDefs(
|
||||
nnkIdent(!"y"),
|
||||
nnkIdent(!"float32"),
|
||||
nnkIdent(!"y"),
|
||||
nnkIdent(!"float32"),
|
||||
nnkEmpty()
|
||||
)
|
||||
nnkPragma(nnkIdent(!"inline")),
|
||||
@@ -1271,7 +1271,7 @@ AST:
|
||||
),
|
||||
# ...
|
||||
|
||||
When a procedure uses the special ``var`` type return variable, the result
|
||||
When a procedure uses the special ``var`` type return variable, the result
|
||||
is different from that of a var section.
|
||||
|
||||
Concrete syntax:
|
||||
@@ -1292,7 +1292,7 @@ AST:
|
||||
Iterator declaration
|
||||
--------------------
|
||||
|
||||
The syntax for iterators is similar to procs, but with ``nnkIteratorDef``
|
||||
The syntax for iterators is similar to procs, but with ``nnkIteratorDef``
|
||||
replacing ``nnkProcDef``.
|
||||
|
||||
Concrete syntax:
|
||||
@@ -1333,7 +1333,7 @@ Template declaration
|
||||
Templates (as well as macros, as we'll see) have a slightly expanded AST when
|
||||
compared to procs and iterators. The reason for this is [term-rewriting
|
||||
macros](http://nim-lang.org/docs/manual.html#term-rewriting-macros). Notice
|
||||
the ``nnkEmpty()`` as the second argument to ``nnkProcDef`` and
|
||||
the ``nnkEmpty()`` as the second argument to ``nnkProcDef`` and
|
||||
``nnkIteratorDef`` above? That's where the term-rewriting macros go.
|
||||
|
||||
Concrete syntax:
|
||||
@@ -1358,16 +1358,16 @@ inside ``nnkFormalParams`` just becomes ``nnkEmpty``.
|
||||
Macro declaration
|
||||
-----------------
|
||||
|
||||
Macros behave like templates, but ``nnkTemplateDef`` is replaced with
|
||||
Macros behave like templates, but ``nnkTemplateDef`` is replaced with
|
||||
``nnkMacroDef``.
|
||||
|
||||
|
||||
Special node kinds
|
||||
==================
|
||||
|
||||
There are several node kinds that are used for semantic checking or code
|
||||
There are several node kinds that are used for semantic checking or code
|
||||
generation. These are accessible from this module, but should not be used.
|
||||
Other node kinds are especially designed to make AST manipulations easier.
|
||||
These are explained here.
|
||||
These are explained here.
|
||||
|
||||
To be written.
|
||||
|
||||
Reference in New Issue
Block a user