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patch 8.2.5003: cannot do bitwise shifts

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Problem:    Cannot do bitwise shifts.
Solution:   Add the >> and << operators. (Yegappan Lakshmanan, closes #8457)
This commit is contained in:
Yegappan Lakshmanan
2022-05-22 19:13:49 +01:00
committed by Bram Moolenaar
parent 9b2edfd3bf
commit a061f34191
11 changed files with 554 additions and 160 deletions
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145
runtime/doc/eval.txt
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@@ -868,33 +868,36 @@ Expression syntax summary, from least to most significant:
expr5 isnot expr5 different |List|, |Dictionary| or |Blob|
instance
|expr5| expr6
expr6 + expr6 ... number addition, list or blob concatenation
expr6 - expr6 ... number subtraction
expr6 . expr6 ... string concatenation
expr6 .. expr6 ... string concatenation
|expr5| expr6 << expr6 bitwise left shift
expr6 >> expr6 bitwise right shift
|expr6| expr7
expr7 * expr7 ... number multiplication
expr7 / expr7 ... number division
expr7 % expr7 ... number modulo
expr7 + expr7 ... number addition, list or blob concatenation
expr7 - expr7 ... number subtraction
expr7 . expr7 ... string concatenation
expr7 .. expr7 ... string concatenation
|expr7| expr8
<type>expr8 type check and conversion (|Vim9| only)
expr8 * expr8 ... number multiplication
expr8 / expr8 ... number division
expr8 % expr8 ... number modulo
|expr8| expr9
! expr8 logical NOT
- expr8 unary minus
+ expr8 unary plus
<type>expr9 type check and conversion (|Vim9| only)
|expr9| expr10
expr9[expr1] byte of a String or item of a |List|
expr9[expr1 : expr1] substring of a String or sublist of a |List|
expr9.name entry in a |Dictionary|
expr9(expr1, ...) function call with |Funcref| variable
expr9->name(expr1, ...) |method| call
! expr9 logical NOT
- expr9 unary minus
+ expr9 unary plus
|expr10| number number constant
|expr10| expr11
expr10[expr1] byte of a String or item of a |List|
expr10[expr1 : expr1] substring of a String or sublist of a |List|
expr10.name entry in a |Dictionary|
expr10(expr1, ...) function call with |Funcref| variable
expr10->name(expr1, ...) |method| call
|expr11| number number constant
"string" string constant, backslash is special
'string' string constant, ' is doubled
[expr1, ...] |List|
@@ -1128,14 +1131,26 @@ can be matched like an ordinary character. Examples:
"foo\nbar" =~ "\\n" evaluates to 0
expr5 and expr6 *expr5* *expr6* *E1036* *E1051*
---------------
expr6 + expr6 Number addition, |List| or |Blob| concatenation *expr-+*
expr6 - expr6 Number subtraction *expr--*
expr6 . expr6 String concatenation *expr-.*
expr6 .. expr6 String concatenation *expr-..*
expr5 *expr5* *bitwise-shift*
-----
expr6 << expr6 bitwise left shift *expr-<<*
expr6 >> expr6 bitwise right shift *expr->>*
*E1282* *E1283*
The "<<" and ">>" operators can be used to perform bitwise left or right shift
of the left operand by the number of bits specified by the right operand. The
operands must be positive numbers. The topmost bit (sign bit) is always
cleared for ">>". If the right operand (shift amount) is more than the
maximum number of bits in a number (|v:numbersize|) the result is zero.
For |Lists| only "+" is possible and then both expr6 must be a list. The
expr6 and expr7 *expr6* *expr7* *E1036* *E1051*
---------------
expr7 + expr7 Number addition, |List| or |Blob| concatenation *expr-+*
expr7 - expr7 Number subtraction *expr--*
expr7 . expr7 String concatenation *expr-.*
expr7 .. expr7 String concatenation *expr-..*
For |Lists| only "+" is possible and then both expr7 must be a list. The
result is a new list with the two lists Concatenated.
For String concatenation ".." is preferred, since "." is ambiguous, it is also
@@ -1147,9 +1162,9 @@ In |Vim9| script the arguments of ".." are converted to String for simple
types: Number, Float, Special and Bool. For other types |string()| should be
used.
expr7 * expr7 Number multiplication *expr-star*
expr7 / expr7 Number division *expr-/*
expr7 % expr7 Number modulo *expr-%*
expr8 * expr8 Number multiplication *expr-star*
expr8 / expr8 Number division *expr-/*
expr8 % expr8 Number modulo *expr-%*
In legacy script, for all operators except "." and "..", Strings are converted
to Numbers.
@@ -1191,18 +1206,18 @@ None of these work for |Funcref|s.
".", ".." and "%" do not work for Float. *E804* *E1035*
expr7 *expr7*
expr8 *expr8*
-----
<type>expr8
<type>expr9
This is only available in |Vim9| script, see |type-casting|.
expr8 *expr8*
expr9 *expr9*
-----
! expr8 logical NOT *expr-!*
- expr8 unary minus *expr-unary--*
+ expr8 unary plus *expr-unary-+*
! expr9 logical NOT *expr-!*
- expr9 unary minus *expr-unary--*
+ expr9 unary plus *expr-unary-+*
For '!' |TRUE| becomes |FALSE|, |FALSE| becomes |TRUE| (one).
For '-' the sign of the number is changed.
@@ -1224,21 +1239,21 @@ These three can be repeated and mixed. Examples:
--9 == 9
expr9 *expr9*
-----
This expression is either |expr10| or a sequence of the alternatives below,
expr10 *expr10*
------
This expression is either |expr11| or a sequence of the alternatives below,
in any order. E.g., these are all possible:
expr9[expr1].name
expr9.name[expr1]
expr9(expr1, ...)[expr1].name
expr9->(expr1, ...)[expr1]
expr10[expr1].name
expr10.name[expr1]
expr10(expr1, ...)[expr1].name
expr10->(expr1, ...)[expr1]
Evaluation is always from left to right.
expr9[expr1] item of String or |List| *expr-[]* *E111*
expr10[expr1] item of String or |List| *expr-[]* *E111*
*E909* *subscript* *E1062*
In legacy Vim script:
If expr9 is a Number or String this results in a String that contains the
expr1'th single byte from expr9. expr9 is used as a String (a number is
If expr10 is a Number or String this results in a String that contains the
expr1'th single byte from expr10. expr10 is used as a String (a number is
automatically converted to a String), expr1 as a Number. This doesn't
recognize multibyte encodings, see `byteidx()` for an alternative, or use
`split()` to turn the string into a list of characters. Example, to get the
@@ -1246,8 +1261,8 @@ byte under the cursor: >
:let c = getline(".")[col(".") - 1]
In |Vim9| script: *E1147* *E1148*
If expr9 is a String this results in a String that contains the expr1'th
single character (including any composing characters) from expr9. To use byte
If expr10 is a String this results in a String that contains the expr1'th
single character (including any composing characters) from expr10. To use byte
indexes use |strpart()|.
Index zero gives the first byte or character. Careful: text column numbers
@@ -1258,7 +1273,7 @@ String. A negative index always results in an empty string (reason: backward
compatibility). Use [-1:] to get the last byte or character.
In Vim9 script a negative index is used like with a list: count from the end.
If expr9 is a |List| then it results the item at index expr1. See |list-index|
If expr10 is a |List| then it results the item at index expr1. See |list-index|
for possible index values. If the index is out of range this results in an
error. Example: >
:let item = mylist[-1] " get last item
@@ -1268,14 +1283,14 @@ Generally, if a |List| index is equal to or higher than the length of the
error.
expr9[expr1a : expr1b] substring or sublist *expr-[:]*
expr10[expr1a : expr1b] substring or sublist *expr-[:]*
If expr9 is a String this results in the substring with the bytes or
characters from expr1a to and including expr1b. expr9 is used as a String,
If expr10 is a String this results in the substring with the bytes or
characters from expr1a to and including expr1b. expr10 is used as a String,
expr1a and expr1b are used as a Number.
In legacy Vim script the indexes are byte indexes. This doesn't recognize
multibyte encodings, see |byteidx()| for computing the indexes. If expr9 is
multibyte encodings, see |byteidx()| for computing the indexes. If expr10 is
a Number it is first converted to a String.
In Vim9 script the indexes are character indexes and include composing
@@ -1302,20 +1317,20 @@ Examples: >
:let s = s[:-3] " remove last two bytes
<
*slice*
If expr9 is a |List| this results in a new |List| with the items indicated by
If expr10 is a |List| this results in a new |List| with the items indicated by
the indexes expr1a and expr1b. This works like with a String, as explained
just above. Also see |sublist| below. Examples: >
:let l = mylist[:3] " first four items
:let l = mylist[4:4] " List with one item
:let l = mylist[:] " shallow copy of a List
If expr9 is a |Blob| this results in a new |Blob| with the bytes in the
If expr10 is a |Blob| this results in a new |Blob| with the bytes in the
indexes expr1a and expr1b, inclusive. Examples: >
:let b = 0zDEADBEEF
:let bs = b[1:2] " 0zADBE
:let bs = b[:] " copy of 0zDEADBEEF
Using expr9[expr1] or expr9[expr1a : expr1b] on a |Funcref| results in an
Using expr10[expr1] or expr10[expr1a : expr1b] on a |Funcref| results in an
error.
Watch out for confusion between a namespace and a variable followed by a colon
@@ -1324,11 +1339,11 @@ for a sublist: >
mylist[s:] " uses namespace s:, error!
expr9.name entry in a |Dictionary| *expr-entry*
expr10.name entry in a |Dictionary| *expr-entry*
*E1203* *E1229*
If expr9 is a |Dictionary| and it is followed by a dot, then the following
If expr10 is a |Dictionary| and it is followed by a dot, then the following
name will be used as a key in the |Dictionary|. This is just like:
expr9[name].
expr10[name].
The name must consist of alphanumeric characters, just like a variable name,
but it may start with a number. Curly braces cannot be used.
@@ -1345,17 +1360,17 @@ Note that the dot is also used for String concatenation. To avoid confusion
always put spaces around the dot for String concatenation.
expr9(expr1, ...) |Funcref| function call *E1085*
expr10(expr1, ...) |Funcref| function call *E1085*
When expr9 is a |Funcref| type variable, invoke the function it refers to.
When expr10 is a |Funcref| type variable, invoke the function it refers to.
expr9->name([args]) method call *method* *->*
expr9->{lambda}([args])
expr10->name([args]) method call *method* *->*
expr10->{lambda}([args])
*E260* *E276* *E1265*
For methods that are also available as global functions this is the same as: >
name(expr9 [, args])
There can also be methods specifically for the type of "expr9".
name(expr10 [, args])
There can also be methods specifically for the type of "expr10".
This allows for chaining, passing the value that one method returns to the
next method: >
@@ -1364,7 +1379,7 @@ next method: >
Example of using a lambda: >
GetPercentage()->{x -> x * 100}()->printf('%d%%')
<
When using -> the |expr8| operators will be applied first, thus: >
When using -> the |expr9| operators will be applied first, thus: >
-1.234->string()
Is equivalent to: >
(-1.234)->string()
@@ -1393,7 +1408,7 @@ When using the lambda form there must be no white space between the } and the
(.
*expr10*
*expr11*
number
------
number number constant *expr-number*