reworked .filter(..) path syntax + notes + docs...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>
This commit is contained in:
Alex A. Naanou 2018-08-26 01:49:06 +03:00
parent 13492f9907
commit a6149be9b4
2 changed files with 141 additions and 97 deletions

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@ -262,9 +262,31 @@ Apply "diff* (or *patch*) `X` to `X'` state.
`diff.unpatch(X') -> X`
Undo *diff" application to `X'` returning it to `X` state.
This is equivalent to: `diff.reverse().patch(X')`
`diff.check(X) -> bool`
Check if *diff* is compatible/applicable to `X`. This essentially checks if the *left hand side* of the *diff* matches the corresponding nodes of `X`.
`diff.reverse() -> diff`
Generate a new *child diff* where `A` and `B` are reversed.
`diff.filter(path | filter) -> diff`
Generate a new *child diff* leaving only changes that match the `path`/`filter`
The `path` is a `"/"` or `"\"` separated string that supports the following item syntax:
- `"*"` - matches any item (same as: `ANY`).
- `"**"` - matches 0 or more items.
- `"a|b"` - matches either `a` or `b` (same as: `OR('a', 'b')`)
- `"!a"` - matches anything but `a` (smae as: `NOT('a')`)
*Note that `"**"` is a special case in that it can not be combined with other patterns above (e.g. in `"a|**"` the string `"**"` is treated literally and has not special meaning).*
`diff.merge(diff) -> diff`
XXX
`diff.end() -> diff`
Return the *parent diff* that was used to generate the current *child diff* or the current diff if there is not parent.
`diff.json() -> JSON`
Serialize the *diff* to JSON. Note that the output may or may not be JSON compatible depending on the inputs.

216
diff.js
View File

@ -969,6 +969,122 @@ module.Types = {
})
},
// Filter diff changes and return a new diff...
//
// .filter(path)
// .filter(func)
// -> diff
//
// path can be either a '/' separated string of path elements or
// an array...
//
// path if given as a string supports the following syntax:
// * - matches any single path element (like ANY)
// a|b - matches either a or b
// !a - matches anything but a
// XXX do we need grouping and quoting???
//
// Special case:
// ** - matches 0 or more path elements
// NOTE: '**' can't be used with other patterns from
// the above.
//
// NOTE: array path also supports patterns...
filter: function(diff, filter){
// string filter...
filter = typeof(filter) == typeof('str') ?
filter
.trim()
// remove leading and trailing '/' or '\'
.replace(/(^[\\\/]+|[\\\/]+$)/g, '')
.split(/[\\\/]+/)
// 'a|b' -> OR('a', 'b')
// '*' -> ANY
// '!a' -> NOT('a')
// NOTE: '**' is handled differently and later...
.map(function(e){
e = e
.split(/\|/)
.map(function(e){
return e == '*' ? ANY
: e[0] == '!' ? NOT(e.slice(1))
: e })
return e.length == 1 ? e[0] : OR(...e)
})
: filter
// path filter (non-function)...
if(!(filter instanceof Function)){
// normalize path...
// format:
// [
// '**' | [ .. ],
// ...
// ]
// XXX when OF(..) is ready, replace '**' with OF(ANY, ANY)...
var pattern = (filter instanceof Array ? filter : [filter])
// remove consecutive repeating '**'
.filter(function(e, i, lst){
return e == '**' && lst[i-1] != '**' || true })
// split to array sections at '**'...
.reduce(function(res, e){
var n = res.length-1
e == '**' ?
res.push('**')
: (res.length == 0 || res[n] == '**') ?
res.push([e])
: res[n].push(e)
return res
}, [])
// min length...
var min = pattern
.reduce(function(l, e){
return l + (e instanceof Array ? e.length : 0) }, 0)
// XXX account for pattern/path end...
var test = function(path, pattern){
return (
// end of path/pattern...
path.length == 0 && pattern.length == 0 ?
true
// consumed pattern with path left over -> fail...
: (path.length > 0 && pattern.length == 0)
|| (path.length == 0 && pattern.length > 1)?
false
// '**' -> test, skip elem and repeat...
: pattern[0] == '**' ?
(test(path, pattern.slice(1))
|| test(path.slice(1), pattern))
// compare sections...
: (cmp(
path.slice(0, pattern[0].length),
pattern[0])
// test next section...
&& test(
path.slice(pattern[0].length),
pattern.slice(1)))) }
// XXX Q: should we ignore the last element of the path???
filter = function(change, i, lst){
return test(change.path, pattern) }
}
return diff.filter(filter.bind(this))
},
// XXX there are two approaches to this:
// 1) naive: simply concatenate all the changes in order...
// 2) filter and merge changes based on path...
// XXX do we need a conflict resolution policy???
merge: function(diff, other){
// XXX
return this.flatten(diff).concat(this.flatten(other))
},
// User API...
@ -1260,95 +1376,6 @@ module.Types = {
: !that.cmp(change.A, target[key])
})
},
// Filter diff changes and return a new diff...
//
// .filter(path)
// .filter(func)
// -> diff
//
// path can be either a '/' separated string of path elements or
// an array...
//
// path supports a limited glob syntax:
// * - matches any single path element (like ANY)
// ** - matches 0 or more path elements
//
// NOTE: array path also supports patterns...
//
filter: function(diff, filter){
// string filter...
filter = typeof(filter) == typeof('str') ?
filter.split(/[\\\/]/)
: filter
// path filter (non-function)...
if(!(filter instanceof Function)){
// normalize path...
// format:
// [
// '**' | [ .. ],
// ...
// ]
// XXX when OF(..) is ready, replace '**' with OF(ANY, ANY)...
var pattern = (filter instanceof Array ? filter : [filter])
// '*' -> ANY
.map(function(e){
return e == '*' ? ANY : e })
// remove consecutive repeating '**'
.filter(function(e, i, lst){
return e == '**' && lst[i-1] != '**' || true })
// split to array sections at '**'...
.reduce(function(res, e){
var n = res.length-1
e == '**' ?
res.push('**')
: (res.length == 0 || res[n] == '**') ?
res.push([e])
: res[n].push(e)
return res
}, [])
// min length...
var min = pattern
.reduce(function(l, e){
return l + (e instanceof Array ? e.length : 0) }, 0)
// XXX account for pattern/path end...
var test = function(path, pattern){
return (
// end of path/pattern...
path.length == 0 && pattern.length == 0 ?
true
// consumed pattern with path left over -> fail...
: (path.length > 0 && pattern.length == 0)
|| (path.length == 0 && pattern.length > 1)?
false
// '**' -> test, skip elem and repeat...
: pattern[0] == '**' ?
(test(path, pattern.slice(1))
|| test(path.slice(1), pattern))
// compare sections...
: (cmp(
path.slice(0, pattern[0].length),
pattern[0])
// test next section...
&& test(
path.slice(pattern[0].length),
pattern.slice(1)))) }
// XXX Q: should we ignore the last element of the path???
filter = function(change, i, lst){
return test(change.path, pattern) }
}
return diff.filter(filter.bind(this))
},
}
@ -2217,17 +2244,12 @@ var DiffPrototype = {
res.parent = this
return res
},
// XXX
// XXX should this set .parent ????
merge: function(diff){
var res = this.clone()
// XXX there are two approaches to this:
// 1) naive: simply concatenate all the changes in order...
// 2) filter and merge changes based on path...
// XXX do we need a conflict resolution policy???
res.diff = this.constructor.types.merge.call(this, this.diff, diff.diff)
res.parent = this
return res
},