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changed comment handling (breaking change)

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This commit is contained in:
Araq
2014-09-07 00:58:31 +02:00
parent ef001573df
commit 1cdb8022d0
3 changed files with 49 additions and 80 deletions
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47
compiler/lexer.nim
View File

@@ -482,7 +482,7 @@ proc getEscapedChar(L: var TLexer, tok: var TToken) =
add(tok.literal, VT)
inc(L.bufpos)
of 't', 'T':
add(tok.literal, Tabulator)
add(tok.literal, '\t')
inc(L.bufpos)
of '\'', '\"':
add(tok.literal, L.buf[L.bufpos])
@@ -659,28 +659,29 @@ proc getOperator(L: var TLexer, tok: var TToken) =
if buf[pos] in {CR, LF, nimlexbase.EndOfFile}:
tok.strongSpaceB = -1
proc scanComment(L: var TLexer, tok: var TToken) =
proc scanComment(L: var TLexer, tok: var TToken) =
var pos = L.bufpos
var buf = L.buf
# a comment ends if the next line does not start with the # on the same
# column after only whitespace
when not defined(nimfix): assert buf[pos+1] == '#'
var buf = L.buf
tok.tokType = tkComment
# iNumber contains the number of '\n' in the token
tok.iNumber = 0
var col = getColNumber(L, pos)
when defined(nimfix):
var col = getColNumber(L, pos)
while true:
var lastBackslash = -1
while buf[pos] notin {CR, LF, nimlexbase.EndOfFile}:
if buf[pos] == '\\': lastBackslash = pos+1
add(tok.literal, buf[pos])
inc(pos)
if lastBackslash > 0:
# a backslash is a continuation character if only followed by spaces
# plus a newline:
while buf[lastBackslash] == ' ': inc(lastBackslash)
if buf[lastBackslash] notin {CR, LF, nimlexbase.EndOfFile}:
# false positive:
lastBackslash = -1
when defined(nimfix):
if lastBackslash > 0:
# a backslash is a continuation character if only followed by spaces
# plus a newline:
while buf[lastBackslash] == ' ': inc(lastBackslash)
if buf[lastBackslash] notin {CR, LF, nimlexbase.EndOfFile}:
# false positive:
lastBackslash = -1
pos = handleCRLF(L, pos)
buf = L.buf
@@ -688,9 +689,16 @@ proc scanComment(L: var TLexer, tok: var TToken) =
while buf[pos] == ' ':
inc(pos)
inc(indent)
if buf[pos] == '#' and (col == indent or lastBackslash > 0):
when defined(nimfix):
template doContinue(): expr =
buf[pos] == '#' and (col == indent or lastBackslash > 0)
else:
template doContinue(): expr =
buf[pos] == '#' and buf[pos+1] == '#'
if doContinue():
tok.literal.add "\n"
col = indent
when defined(nimfix): col = indent
inc tok.iNumber
else:
if buf[pos] > ' ':
@@ -707,7 +715,7 @@ proc skip(L: var TLexer, tok: var TToken) =
of ' ':
inc(pos)
inc(tok.strongSpaceA)
of Tabulator:
of '\t':
lexMessagePos(L, errTabulatorsAreNotAllowed, pos)
inc(pos)
of CR, LF:
@@ -718,7 +726,12 @@ proc skip(L: var TLexer, tok: var TToken) =
inc(pos)
inc(indent)
tok.strongSpaceA = 0
if buf[pos] > ' ':
when defined(nimfix):
template doBreak(): expr = buf[pos] > ' '
else:
template doBreak(): expr =
buf[pos] > ' ' and (buf[pos] != '#' or buf[pos+1] == '#')
if doBreak():
tok.indent = indent
L.currLineIndent = indent
break

35
doc/manual.txt
View File

@@ -156,33 +156,20 @@ Comments start anywhere outside a string or character literal with the
hash character ``#``.
Comments consist of a concatenation of `comment pieces`:idx:. A comment piece
starts with ``#`` and runs until the end of the line. The end of line characters
belong to the piece. If the next line only consists of a comment piece which is
aligned to the preceding one, it does not start a new comment:
belong to the piece. If the next line only consists of a comment piece with
no other tokens between it and the preceding one, it does not start a new
comment:
.. code-block:: nim
i = 0 # This is a single comment over multiple lines belonging to the
# assignment statement. The scanner merges these two pieces.
# This is a new comment belonging to the current block, but to no particular
# statement.
i = i + 1 # This a new comment that is NOT
echo(i) # continued here, because this comment refers to the echo statement
i = 0 # This is a single comment over multiple lines.
# The scanner merges these two pieces.
# The comment continues here.
The alignment requirement does not hold if the preceding comment piece ends in
a backslash (followed by optional whitespace):
.. code-block:: nim
type
TMyObject {.final, pure, acyclic.} = object # comment continues: \
# we have lots of space here to comment 'TMyObject'.
# This line belongs to the comment as it's properly aligned.
Comments are tokens; they are only allowed at certain places in the input file
as they belong to the syntax tree! This feature enables perfect source-to-source
transformations (such as pretty-printing) and superior documentation generators.
A nice side-effect is that the human reader of the code always knows exactly
which code snippet the comment refers to.
`Documentation comments`:idx: are comments that start with two ``##``.
Documentation comments are tokens; they are only allowed at certain places in
the input file as they belong to the syntax tree!
Identifiers & Keywords
@@ -5804,7 +5791,7 @@ Spawn
Nim has a builtin thread pool that can be used for CPU intensive tasks. For
IO intensive tasks the upcoming ``async`` and ``await`` features should be
used instead. `spawn`:idx: is used to pass a task to the thread pool:
used. `spawn`:idx: is used to pass a task to the thread pool:
.. code-block:: nim
proc processLine(line: string) =

47
doc/tut1.txt
View File

@@ -112,50 +112,19 @@ Comments
--------
Comments start anywhere outside a string or character literal with the
hash character ``#``. Documentation comments start with ``##``. Multiline
comments need to be aligned at the same column:
hash character ``#``. Documentation comments start with ``##``:
.. code-block:: nim
i = 0 # This is a single comment over multiple lines belonging to the
# assignment statement.
# This is a new comment belonging to the current block, but to no particular
# statement.
i = i + 1 # This a new comment that is NOT
echo(i) # continued here, because this comment refers to the echo statement
# A comment.
var myVariable: int ## a documentation comment
The alignment requirement does not hold if the preceding comment piece ends in
a backslash:
Documentation comments are tokens; they are only allowed at certain places in
the input file as they belong to the syntax tree! This feature enables simpler
documentation generators.
.. code-block:: nim
type
TMyObject {.final, pure, acyclic.} = object # comment continues: \
# we have lots of space here to comment 'TMyObject'.
# This line belongs to the comment as it's properly aligned.
Comments are tokens; they are only allowed at certain places in the input file
as they belong to the syntax tree! This feature enables perfect source-to-source
transformations (such as pretty-printing) and simpler documentation generators.
A nice side-effect is that the human reader of the code always knows exactly
which code snippet the comment refers to. Since comments are a proper part of
the syntax, watch their indentation:
.. code-block::
echo("Hello!")
# comment has the same indentation as above statement -> fine
echo("Hi!")
# comment has not the correct indentation level -> syntax error!
**Note**: To comment out a large piece of code, it is often better to use a
``when false:`` statement.
.. code-block:: nim
when false:
brokenCode()
Another option is to use the `discard statement`_ together with *long string
You can also use the `discard statement`_ together with *long string
literals* to create block comments:
.. code-block:: nim