Sublime Keymap - shift+space to go back one character in given context - sublimetext

Question

On my sublime-keymap file I already have this:
{ "keys": ["shift+space"], "command": "move", "args": {"by": "characters", "forward": true}, "context":
[
{ "key": "following_text", "operator": "regex_contains", "operand": "^[ )'\"\\}\\]>: ]", "match_all": true },
{ "key": "auto_complete_visible", "operator": "equal", "operand": false }
]
}
So, when my cursor is before any of these characters )}]:;> the shift+space will move the cursor to the right, jumping the character. This is very useful and already well known.
Now I was thinking that would be nice to have the inverse too. Imagine that I just jumped a closing } but then I remember that I still had something to type inside the {}. It would be great to be able to do shift+space again and get back inside the {}.
I was checking this documentation but everything I tried didn't worked.
Any help or ideas on this? Tks!
EDIT : BASED ON CORRECT ANSWER:
So, based on #skuroda's answer, this is what I came up with. For more information, read the comments below his answer.
{ "keys": ["shift+space"], "command": "move", "args": {"by": "characters", "forward": false}, "context":
[
{ "key": "preceding_text", "operator": "regex_contains", "operand": "[)'\"\\}\\]>,\\;:]$", "match_all": true },
{ "key": "auto_complete_visible", "operator": "equal", "operand": false }
]
},
{ "keys": ["shift+space"], "command": "move", "args": {"by": "characters", "forward": true}, "context":
[
{ "key": "following_text", "operator": "regex_contains", "operand": "^[)'\"\\}\\]>,\\;:]", "match_all": true },
{ "key": "auto_complete_visible", "operator": "equal", "operand": false }
]
},
The order of the code is important (preceding_text command must come before following_text one).
UPDATE: I think I found a much simpler and better solution for this:
{ "keys": ["shift+space"], "command": "move", "args": {"by": "characters", "forward": true} },
{ "keys": ["super+shift+space"], "command": "move", "args": {"by": "characters", "forward": false} }
So, the context doesn't really matter here. Shift + Space will advance one character, CMD + Shift + Space will go back one character. Pure joy!

Answer 1

Have you tried the preceding_text key, so something like
{ "keys": ["shift+space"], "command": "move", "args": {"by": "characters", "forward": false}, "context":
[
{ "key": "preceding_text", "operator": "regex_contains", "operand": "[ )'\"\\}\\]>: ]$", "match_all": true },
{ "key": "auto_complete_visible", "operator": "equal", "operand": false }
]
}
If you have tried that, it's probably worth posting what you have already tried, so we don't repeat things you have already done (rather than just stating you have tried stuff). I also modified the regex slightly.