diff options
Diffstat (limited to 'runtime/doc/eval.txt')
| -rw-r--r-- | runtime/doc/eval.txt | 78 |
1 files changed, 49 insertions, 29 deletions
diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt index 17ed0b2d0f..00194b4613 100644 --- a/runtime/doc/eval.txt +++ b/runtime/doc/eval.txt @@ -610,10 +610,10 @@ Expression syntax summary, from least to most significant: expr2 ? expr1 : expr1 if-then-else |expr2| expr3 - expr3 || expr3 .. logical OR + expr3 || expr3 ... logical OR |expr3| expr4 - expr4 && expr4 .. logical AND + expr4 && expr4 ... logical AND |expr4| expr5 expr5 == expr5 equal @@ -634,14 +634,15 @@ Expression syntax summary, from least to most significant: expr5 isnot expr5 different |List| instance |expr5| expr6 - expr6 + expr6 .. number addition or list concatenation - expr6 - expr6 .. number subtraction - expr6 . expr6 .. string concatenation + expr6 + expr6 ... number addition, list or blob concatenation + expr6 - expr6 ... number subtraction + expr6 . expr6 ... string concatenation + expr6 .. expr6 ... string concatenation |expr6| expr7 - expr7 * expr7 .. number multiplication - expr7 / expr7 .. number division - expr7 % expr7 .. number modulo + expr7 * expr7 ... number multiplication + expr7 / expr7 ... number division + expr7 % expr7 ... number modulo |expr7| expr8 ! expr7 logical NOT @@ -670,7 +671,7 @@ Expression syntax summary, from least to most significant: {args -> expr1} lambda expression -".." indicates that the operations in this level can be concatenated. +"..." indicates that the operations in this level can be concatenated. Example: > &nu || &list && &shell == "csh" @@ -707,7 +708,9 @@ use in a variable such as "a:1". expr2 and expr3 *expr2* *expr3* --------------- - *expr-barbar* *expr-&&* +expr3 || expr3 .. logical OR *expr-barbar* +expr4 && expr4 .. logical AND *expr-&&* + The "||" and "&&" operators take one argument on each side. The arguments are (converted to) Numbers. The result is: @@ -847,18 +850,22 @@ can be matched like an ordinary character. Examples: expr5 and expr6 *expr5* *expr6* --------------- -expr6 + expr6 .. Number addition or |List| concatenation *expr-+* -expr6 - expr6 .. Number subtraction *expr--* -expr6 . expr6 .. String concatenation *expr-.* +expr6 + expr6 Number addition, |List| or |Blob| concatenation *expr-+* +expr6 - expr6 Number subtraction *expr--* +expr6 . expr6 String concatenation *expr-.* +expr6 .. expr6 String concatenation *expr-..* For |Lists| only "+" is possible and then both expr6 must be a list. The result is a new list with the two lists Concatenated. -expr7 * expr7 .. Number multiplication *expr-star* -expr7 / expr7 .. Number division *expr-/* -expr7 % expr7 .. Number modulo *expr-%* +For String concatenation ".." is preferred, since "." is ambiguous, it is also +used for |Dict| member access and floating point numbers. + +expr7 * expr7 Number multiplication *expr-star* +expr7 / expr7 Number division *expr-/* +expr7 % expr7 Number modulo *expr-%* -For all, except ".", Strings are converted to Numbers. +For all, except "." and "..", Strings are converted to Numbers. For bitwise operators see |and()|, |or()| and |xor()|. Note the difference between "+" and ".": @@ -1049,11 +1056,6 @@ These are INVALID: 3. empty {M} 1e40 missing .{M} - *float-pi* *float-e* -A few useful values to copy&paste: > - :let pi = 3.14159265359 - :let e = 2.71828182846 - Rationale: Before floating point was introduced, the text "123.456" was interpreted as the two numbers "123" and "456", both converted to a string and concatenated, @@ -1062,6 +1064,15 @@ could not find it intentionally being used in Vim scripts, this backwards incompatibility was accepted in favor of being able to use the normal notation for floating point numbers. + *float-pi* *float-e* +A few useful values to copy&paste: > + :let pi = 3.14159265359 + :let e = 2.71828182846 +Or, if you don't want to write them in as floating-point literals, you can +also use functions, like the following: > + :let pi = acos(-1.0) + :let e = exp(1.0) +< *floating-point-precision* The precision and range of floating points numbers depends on what "double" means in the library Vim was compiled with. There is no way to change this at @@ -1101,8 +1112,10 @@ A string constant accepts these special characters: \\ backslash \" double quote \<xxx> Special key named "xxx". e.g. "\<C-W>" for CTRL-W. This is for use - in mappings, the 0x80 byte is escaped. Don't use <Char-xxxx> to get a - utf-8 character, use \uxxxx as mentioned above. + in mappings, the 0x80 byte is escaped. + To use the double quote character it must be escaped: "<M-\">". + Don't use <Char-xxxx> to get a utf-8 character, use \uxxxx as + mentioned above. Note that "\xff" is stored as the byte 255, which may be invalid in some encodings. Use "\u00ff" to store character 255 correctly as UTF-8. @@ -1211,8 +1224,8 @@ The arguments are optional. Example: > *closure* Lambda expressions can access outer scope variables and arguments. This is often called a closure. Example where "i" and "a:arg" are used in a lambda -while they exist in the function scope. They remain valid even after the -function returns: > +while they already exist in the function scope. They remain valid even after +the function returns: > :function Foo(arg) : let i = 3 : return {x -> x + i - a:arg} @@ -1220,8 +1233,11 @@ function returns: > :let Bar = Foo(4) :echo Bar(6) < 5 -See also |:func-closure|. Lambda and closure support can be checked with: > - if has('lambda') +Note that the variables must exist in the outer scope before the lamba is +defined for this to work. See also |:func-closure|. + +Lambda and closure support can be checked with: > + if has('lambda') Examples for using a lambda expression with |sort()|, |map()| and |filter()|: > :echo map([1, 2, 3], {idx, val -> val + 1}) @@ -9459,9 +9475,13 @@ This does NOT work: > When the selected range of items is partly past the end of the list, items will be added. - *:let+=* *:let-=* *:let.=* *E734* + *:let+=* *:let-=* *:letstar=* + *:let/=* *:let%=* *:let.=* *E734* :let {var} += {expr1} Like ":let {var} = {var} + {expr1}". :let {var} -= {expr1} Like ":let {var} = {var} - {expr1}". +:let {var} *= {expr1} Like ":let {var} = {var} * {expr1}". +:let {var} /= {expr1} Like ":let {var} = {var} / {expr1}". +:let {var} %= {expr1} Like ":let {var} = {var} % {expr1}". :let {var} .= {expr1} Like ":let {var} = {var} . {expr1}". These fail if {var} was not set yet and when the type of {var} and {expr1} don't fit the operator. |