Add new `functions` flag -V/--inherit-variable

--inherit-variable takes a variable name and snapshots its current
value. When the function is executed, it will have a local variable with
this value already defined. Printing the function source will include
synthesized `set -l` lines for the values.

This is primarily useful for functions that are created on the fly, such
as in `psub`.

1 files changed, 20 insertions, 0 deletions

diff --git a/tests/function.out b/tests/function.out
new file mode 100644
index 00000000..3fa70990
--- /dev/null
+++ b/tests/function.out
@@ -0,0 +1,20 @@
+Testing -V
+$foo: (1)
+1: 'local foo'
+$bar: (5)
+1: 'one'
+2: 'two    2'
+3: '	'
+4: ''
+5: '3'
+$baz: (0)
+Testing -V with changed variables
+$foo: (1)
+1: 'local foo'
+$bar: (5)
+1: 'one'
+2: 'two    2'
+3: '	'
+4: ''
+5: '3'
+$baz: (0)