added the 'x.p[:T]' notation for explicit generic instantiations in combination with the ddot calling syntax

This commit is contained in:
Araq 2018-04-06 22:05:47 +02:00
commit 212fdc5946
9 changed files with 81 additions and 53 deletions

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@ -335,8 +335,8 @@ The concept types can be parametric just like the regular generic types:
AnyTransform3D* = AnyMatrix[4, 4, float]
proc transposed*(m: AnyMatrix): m.TransposedType =
for r in 0 .. <m.R:
for c in 0 .. <m.C:
for r in 0 ..< m.R:
for c in 0 ..< m.C:
result[r, c] = m[c, r]
proc determinant*(m: AnySquareMatrix): int =
@ -550,38 +550,38 @@ object inheritance syntax involving the ``of`` keyword:
proc f(g: BidirectionalGraph) # this one will be preferred if we pass a type
# matching the BidirectionalGraph concept
..
Converter type classes
----------------------
Converter type classes
----------------------
Concepts can also be used to convert a whole range of types to a single type or
a small set of simpler types. This is achieved with a `return` statement within
the concept body:
Concepts can also be used to convert a whole range of types to a single type or
a small set of simpler types. This is achieved with a `return` statement within
the concept body:
.. code-block:: nim
type
Stringable = concept x
$x is string
return $x
.. code-block:: nim
type
Stringable = concept x
$x is string
return $x
StringRefValue[CharType] = object
base: ptr CharType
len: int
StringRefValue[CharType] = object
base: ptr CharType
len: int
StringRef = concept x
# the following would be an overloaded proc for cstring, string, seq and
# other user-defined types, returning either a StringRefValue[char] or
# StringRefValue[wchar]
return makeStringRefValue(x)
StringRef = concept x
# the following would be an overloaded proc for cstring, string, seq and
# other user-defined types, returning either a StringRefValue[char] or
# StringRefValue[wchar]
return makeStringRefValue(x)
# the varargs param will here be converted to an array of StringRefValues
# the proc will have only two instantiations for the two character types
proc log(format: static[string], varargs[StringRef])
# the varargs param will here be converted to an array of StringRefValues
# the proc will have only two instantiations for the two character types
proc log(format: static[string], varargs[StringRef])
# this proc will allow char and wchar values to be mixed in
# the same call at the cost of additional instantiations
# the varargs param will be converted to a tuple
proc log(format: static[string], varargs[distinct StringRef])
# this proc will allow char and wchar values to be mixed in
# the same call at the cost of additional instantiations
# the varargs param will be converted to a tuple
proc log(format: static[string], varargs[distinct StringRef])
..

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@ -411,7 +411,7 @@ Other tokens
The following strings denote other tokens::
` ( ) { } [ ] , ; [. .] {. .} (. .)
` ( ) { } [ ] , ; [. .] {. .} (. .) [:
The `slice`:idx: operator `..`:tok: takes precedence over other tokens that

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@ -141,13 +141,14 @@ The method call syntax conflicts with explicit generic instantiations:
``p[T](x)`` cannot be written as ``x.p[T]`` because ``x.p[T]`` is always
parsed as ``(x.p)[T]``.
**Future directions**: ``p[.T.]`` might be introduced as an alternative syntax
to pass explicit types to a generic and then ``x.p[.T.]`` can be parsed as
``x.(p[.T.])``.
See also: `Limitations of the method call syntax
<#templates-limitations-of-the-method-call-syntax>`_.
The ``[: ]`` notation has been designed to mitigate this issue: ``x.p[:T]``
is rewritten by the parser to ``p[T](x)``, ``x.p[:T](y)`` is rewritten to
``p[T](x, y)``. Note that ``[: ]`` has no AST representation, the rewrite
is performed directly in the parsing step.
Properties
----------