patch 8.2.1798: Vim9: trinary operator condition is too permissive
Problem: Vim9: trinary operator condition is too permissive.
Solution: Use tv_get_bool_chk().
diff --git a/runtime/doc/vim9.txt b/runtime/doc/vim9.txt
index 0c20bae..feb889d 100644
--- a/runtime/doc/vim9.txt
+++ b/runtime/doc/vim9.txt
@@ -164,15 +164,20 @@
When using `:function` or `:def` to specify a nested function inside a `:def`
function, this nested function is local to the code block it is defined in.
-In a `:def` function IT is not possible to define a script-local function. it
+In a `:def` function it is not possible to define a script-local function. it
is possible to define a global function by using the "g:" prefix.
When referring to a function and no "s:" or "g:" prefix is used, Vim will
-prefer using a local function (in the function scope, script scope or
-imported) before looking for a global function. However, it is recommended to
-always use "g:" to refer to a local function for clarity. In all cases the
-function must be defined before used. That is when it is first called or when
-`:defcompile` causes the call to be compiled.
+search for the function:
+- in the function scope
+- in the script scope, possibly imported
+- in the list of global functions
+However, it is recommended to always use "g:" to refer to a global function
+for clarity.
+
+In all cases the function must be defined before used. That is when it is
+called, when `:defcompile` causes the it to be compiled, or when code that
+calls it is being compiled (to figure out the return type).
The result is that functions and variables without a namespace can usually be
found in the script, either defined there or imported. Global functions and
@@ -467,11 +472,21 @@
Conditions and expressions ~
-Conditions and expressions are mostly working like they do in JavaScript. A
-difference is made where JavaScript does not work like most people expect.
-Specifically, an empty list is falsy.
+Conditions and expressions are mostly working like they do in other languages.
+Some values are different from legacy Vim script:
+ value legacy Vim script Vim9 script ~
+ 0 falsy falsy
+ 1 truthy truthy
+ 99 truthy Error!
+ "0" falsy Error!
+ "99" truthy Error!
+ "text" falsy Error!
- type TRUE when ~
+For the "??" operator and when using "!" then there is no error, every value
+is either falsy or truthy. This is mostly like JavaScript, except that an
+empty list and dict is falsy:
+
+ type truthy when ~
bool v:true or 1
number non-zero
float non-zero
@@ -498,13 +513,13 @@
[] || 99 Error!
When using "!" for inverting, there is no error for using any type and the
-result is a boolean: >
+result is a boolean. "!!" can be used to turn any value into boolean: >
!'yes' == false
- var myList = [1, 2, 3]
- !!myList == true
+ !![] == false
+ !![1, 2, 3] == true
When using "`.."` for string concatenation arguments of simple types are
-always converted to string. >
+always converted to string: >
'hello ' .. 123 == 'hello 123'
'hello ' .. v:true == 'hello v:true'