Array as value in a lua table - arrays

I couldn't find an answer to my question: Can you have an array as value in a lua table?
local colors = {"blue" = {0,0,1,1}, "green" = {0,1,0,1}, "red" = {1,0,0,1} , "orange" = {0.5, 0, 0.5, 1}, "black" = {0,0,0,1}, "gold" = {1, 215/255, 0, 1}}
I get the error on this line using the corona sdk:
'}' expected near '='

It's tables all the way down :-) Yes, tables (including ones indexed like arrays) can be elements of tables in Lua. This chapter in the Lua manual explains the different ways of defining the elements of a table.
In your example, you should not put quotation marks around the key.
local colors = { blue = { 0, 1, ...}, green = { ... }, ... }
Or you can do:
local colors = {}
colors[ "blue" ] = { 0, ... }
colors[ "green" ] = ...
Or
colors.blue = { 0, .... }
colors.green = ....
The latter is syntactic sugar for the other forms.

Related

LUA pattern matching in nested table

I want to do a pattern match on the table below. If there is a match, take the values of the 2nd and 3rd column as answer. The first column can have 1 or multiple patterns, row 5 has only 1 pattern to match against.
local pattern_matrix = {
{{ "^small%-", "%-small%-", }, "small", 50},
{{ "^medium%-", "%-medium%-", }, "medium", 200},
{{ "^big%-", "%-big%-", }, "big", 3},
{{ "^large%-", "%-large%-", "^L%-", }, "large", 42},
{{ "%-special%-", }, "special", 5},
}
i am using the following code to find the row that matches the input:
local function determine_row(name)
for i = 1,#pattern_matrix,1 do
for _,pattern in pairs(pattern_matrix[i][1]) do --match against column 1
if name:match(pattern) then
return i --match found in row i
end
end
end
return 0
end
the result should be
determine_row("itsamedium") = 2
determine_row("blaspecialdiscount") = 5
determine_row("nodatatomatch") = 0
You're code looks mostly right but the pattern you're using is a bit off. You're not getting the expected index because all the patterns expect hyphens around the words being matched. (due to %- in your pattern)
As Allister mentioned, if you want to match the sample input from your question you can just add that literal word to your list of patterns. Judging from your usage, you may even be able to simplify the pattern. For case insensitive search, use lower() or upper() on your input before matching.
For example:
<script src="https://github.com/fengari-lua/fengari-web/releases/download/v0.1.4/fengari-web.js">
</script>
<script type='application/lua'>
local pattern_matrix =
{
{ "small", 50},
{ "medium", 200},
{ "big", 3},
{ "large", 42},
{ "special", 5},
}
local function determine_row(name)
for i, row in ipairs(pattern_matrix) do
if name:match(row[1]) then
return i -- match found in row i
end
end
return 0
end
local test_input = { "itsa-medium-", "itsBiG no hyphen", "bla-special-discount", "nodatatomatch" }
for _, each in ipairs(test_input) do
print( each, determine_row(each:lower()) )
end
</script>

How to update a particular list of array of lists in state in reactjs

I am using an array in state like this -
this.state = {
shapes : []
}
and shapes array contains data in lists like this-
[
{x: 0, y: 0, height: 10, width: 10},
{x: 10, y: 10, height: 11, width: 11},
...and many more
]
I have taken the x and y coordinates and changed their values.
For ex - for item 1 new values =>
x = 15 and y = 15
How can I update these values in the state?
Sorry about my improper question. I can't think of another way of asking this question.
You have to give while array value as new in set state
this.setState((state) => ({...state, shapes:[{x:15:y:15}, ...state.shapes.slice(1)]}))
I think this is what you're looking for.
this.setState((prevState) => {
const newItems = [...prevState.shapes];
newItems[1].x = 15;
newItems[1].y = 15;
return {shapes: newItems};
});

D3 third argument to .attr() is an array of objects instead of the index [duplicate]

The description of the selection.data function includes an example with multiple groups (link) where a two-dimensional array is turned into an HTML table.
In d3.js v3, for lower dimensions, the accessor functions included a third argument which was the index of the parent group's datum:
td.text(function(d,i,j) {
return "Row: " + j;
});
In v4, this j argument has been replaced by the selection's NodeList. How do I access the parent group's datum index now?
Well, sometimes an answer doesn't provide a solution, because the solution may not exist. This seems to be the case.
According to Bostock:
I’ve merged the new bilevel selection implementation into master and also simplified how parents are tracked by using a parallel parents array.
A nice property of this new approach is that selection.data can
evaluate the values function in exactly the same manner as other
selection functions: the values function gets passed {d, i, nodes}
where this is the parent node, d is the parent datum, i is the parent
(group) index, and nodes is the array of parent nodes (one per group).
Also, the parents array can be reused by subselections that do not
regroup the selection, such as selection.select, since the parents
array is immutable.
This change restricts functionality—in the sense that you cannot
access the parent node from within a selection function, nor the
parent data, nor the group index — but I believe this is ultimately A
Good Thing because it encourages simpler code.
(emphasis mine)
Here's the link: https://github.com/d3/d3-selection/issues/47
So, it's not possible to get the index of the parent's group using selection (the parent's group index can be retrieved using selection.data, as this snippet bellow shows).
var testData = [
[
{x: 1, y: 40},
{x: 2, y: 43},
{x: 3, y: 12},
{x: 6, y: 23}
], [
{x: 1, y: 12},
{x: 4, y: 18},
{x: 5, y: 73},
{x: 6, y: 27}
], [
{x: 1, y: 60},
{x: 2, y: 49},
{x: 3, y: 16},
{x: 6, y: 20}
]
];
var svg = d3.select("body")
.append("svg")
.attr("width", 300)
.attr("height", 300);
var g = svg.selectAll(".groups")
.data(testData)
.enter()
.append("g");
var rects = g.selectAll("rect")
.data(function(d, i , j) { console.log("Data: " + JSON.stringify(d), "\nIndex: " + JSON.stringify(i), "\nNode: " + JSON.stringify(j)); return d})
.enter()
.append("rect");
<script src="https://d3js.org/d3.v4.min.js"></script>
My workaround is somewhat similar to Dinesh Rajan's, assuming the parent index is needed for attribute someAttr of g.nestedElt:
v3:
svg.selectAll(".someClass")
.data(nestedData)
.enter()
.append("g")
.attr("class", "someClass")
.selectAll(".nestedElt")
.data(Object)
.enter()
.append("g")
.attr("class", "nestedElt")
.attr("someAttr", function(d, i, j) {
});
v4:
svg.selectAll(".someClass")
.data(nestedData)
.enter()
.append("g")
.attr("class", "someClass")
.attr("data-index", function(d, i) { return i; }) // make parent index available from DOM
.selectAll(".nestedElt")
.data(Object)
.enter()
.append("g")
.attr("class", "nestedElt")
.attr("someAttr", function(d, i) {
var j = +this.parentNode.getAttribute("data-index");
});
I ended up defining an external variable "j" and then increment it whenever "i" is 0
example V3 snippet below.
rowcols.enter().append("rect")
.attr("x", function (d, i, j) { return CalcXPos(d, j); })
.attr("fill", function (d, i, j) { return GetColor(d, j); })
and in V4, code converted as below.
var j = -1;
rowcols.enter().append("rect")
.attr("x", function (d, i) { if (i == 0) { j++ }; return CalcXPos(d, j); })
.attr("fill", function (d, i) { return GetColor(d, j); })
If j is the nodeList...
j[i] is the current node (eg. the td element),
j[i].parentNode is the level-1 parent (eg. the row element),
j[i].parentNode.parentNode is the level-2 parent (eg. the table element),
j[i].parentNode.parentNode.childNodes is the array of level-1 parents (eg. array of row elements) including the original parent.
So the question is, what is the index of the parent (the row) with respect to it's parent (the table)?
We can find this using Array.prototype.indexOf like so...
k = Array.prototype.indexOf.call(j[i].parentNode.parentNode.childNodes,j[i].parentNode);
You can see in the snippet below that the row is printed in each td cell when k is returned.
var testData = [
[
{x: 1, y: 1},
{x: 1, y: 2},
{x: 1, y: 3},
{x: 1, y: 4}
], [
{x: 2, y: 1},
{x: 2, y: 2},
{x: 2, y: 3},
{x: 2, y: 4}
], [
{x: 3, y: 4},
{x: 3, y: 4},
{x: 3, y: 4},
{x: 3, y: 4}
]
];
var tableData =
d3.select('body').selectAll('table')
.data([testData]);
var tables =
tableData.enter()
.append('table');
var rowData =
tables.selectAll('table')
.data(function(d,i,j){
return d;
});
var rows =
rowData.enter()
.append('tr');
var eleData =
rows.selectAll('tr')
.data(function(d,i,j){
return d;
});
var ele =
eleData.enter()
.append('td')
.text(function(d,i,j){
var k = Array.prototype.indexOf.call(j[i].parentNode.parentNode.childNodes,j[i].parentNode);
return k;
});
<script src="https://d3js.org/d3.v4.min.js"></script>
Reservations
This approach is using DOM order as a proxy for data index. In many cases, I think this is a viable band-aid solution if this is no longer possible in D3 (as reported in this answer).
Some extra effort in manipulating the DOM selection to match data might be needed. As an example, filtering j[i].parentNode.parentNode.childNodes for <tr> elements only in order to determine the row -- generally speaking the childNodes array may not match the selection and could contain extra elements/junk.
While this is not a cure-all, I think it should work or could be made to work in most cases, presuming there is some logical connection between DOM and data that can be leveraged which allows you to use DOM child index as a proxy for data index.
Here's an example of how to use the selection.each() method. I don't think it's messy, but it did slow down the render on a large matrix. Note the following code assumes an existing table selection and a call to update().
update(matrix) {
var self = this;
var tr = table.selectAll("tr").data(matrix);
tr.exit().remove();
tr.enter().append("tr");
tr.each(addCells);
function addCells(data, rowIndex) {
var td = d3.select(this).selectAll("td")
.data(function (d) {
return d;
});
td.exit().remove();
td.enter().append("td");
td.attr("class", function (d) {
return d === 0 ? "dead" : "alive";
});
td.on("click", function(d,i){
matrix[rowIndex][i] = d === 1 ? 0 : 1; // rowIndex now available for use in callback.
});
}
setTimeout(function() {
update(getNewMatrix(matrix))
}, 1000);
},
Assume you want to do a nested selectiom, and your
data is some array where each element in turn
contains an array, let's say "values". Then you
have probably some code like this:
var aInnerSelection = oSelection.selectAll(".someClass") //
.data(d.values) //
...
You can replace the array with the values by a new array, where
you cache the indices within the group.
var aInnerSelection = oSelection.selectAll(".someClass") //
.data(function (d, i) {
var aData = d.values.map(function mapValuesToIndexedValues(elem, index) {
return {
outerIndex: i,
innerIndex: index,
datum: elem
};
})
return aData;
}, function (d, i) {
return d.innerIndex;
}) //
...
Assume your outer array looks like this:
[{name "X", values: ["A", "B"]}, {name "y", values: ["C", "D"]}
With the first approach, the nested selection brings you from here
d i
------------------------------------------------------------------
root dummy X {name "X", values: ["A", "B"]} 0
dummy Y {name "Y", values: ["C", "D"]} 1
to here.
d i
------------------------------------------------------------------
root X A "A" 0
B "B" 1
Y C "C" 2
D "D" 3
With the augmented array, you end up here instead:
d i
------------------------------------------------------------------
root X A {datum: "A", outerIndex: 0, innerIndex: 0} 0
B {datum: "B", outerIndex: 0, innerIndex: 1} 1
Y C {datum: "C", outerIndex: 1, innerIndex: 0} 2
D {datum: "D", outerIndex: 1, innerIndex: 1} 3
So you have within the nested selections, in any function(d,i), all
information you need.
Here's a snippet I crafter after re-remembering this usage of .each for nesting, I thought it may be useful to others who end up here. This examples creates two layers of circles, and the parent group index is used to determine the color of the circles - white for the circles in the first layer, and black for the circles in the top layer (only two layers in this case).
const nested = nest().key(layerValue).entries(data);
let layerGroups = g.selectAll('g.layer').data(nested);
layerGroups = layerGroups.enter().append('g').attr('class', 'layer')
.merge(layerGroups);
layerGroups.each(function(layerEntry, j) {
const circles = select(this)
.selectAll('circle').data(layerEntry.values);
circles.enter().append('circle')
.merge(circles)
.attr('cx', d => xScale(xValue(d)))
.attr('cy', d => yScale(yValue(d)))
.attr('r', d => radiusScale(radiusValue(d)))
.attr('fill', j === 0 ? 'white' : 'black'); // <---- Access parent index.
});
My solution was to embed this information in the data provided to d3js
data = [[1,2,3],[4,5,6],[7,8,9]]
flattened_data = data.reduce((acc, v, i) => {
v.forEach((d, j) => {
data_item = { i, j, d };
acc.push(data_item);
});
return acc;
}, []);
Then you can access i, j and d from the data arg of the function
td.text(function(d) {
// Can access i, j and original data here
return "Row: " + d.j;
});

Angular: How to update an array object key value dynamically?

I am trying to change the points of selected object that in the exp below.
$scope.players = [{
name: 'Kobe',
points: 10,
asists: 0,
rebounds: 0
}, {
name: 'Jordan',
points: 20,
asists: 0,
rebounds: 0
}, {
name: 'Grant',
points: 30,
asists: 0,
rebounds: 0
},
];
and I assign an object selected with its name.
if($scope.playerName == $scope.players[i].name){
$scope.selectedPlayerPoints = $scope.players[i].points;
$scope.selectedPlayerAsists = $scope.players[i].asists;
$scope.selectedPlayerRebounds = $scope.players[i].rebounds;
}
but I can't update them:
$scope.selectedPlayerPoints.push(playerPoints);
To make it more clear please check: http://plnkr.co/edit/B8Nydni586Se79fDpjnq?p=preview
How it works:
1-click on a player
2-click on points = each time 2 points will be added.
3-as you add more point, it will change the object dynamically..(but that is the problem..)
Thnx in advance!
I'm not exactly sure what you want to achieve, but my guess is you have trouble with saving player points.
I've updated your plunkr. Basically instead of passing primitive values:
$scope.selectPlayer = function(name, points, asists, rebounds) { ... }
you should pass object reference:
$scope.selectPlayer = function(player) { ... }

How to compile a C99 source on vc++2008 but without changing the original function?

Such as:
enum {
SPICE_MSG_CURSOR_INIT = 101,
SPICE_MSG_CURSOR_RESET,
SPICE_MSG_CURSOR_SET,
SPICE_MSG_CURSOR_MOVE,
SPICE_MSG_CURSOR_HIDE,
SPICE_MSG_CURSOR_TRAIL,
SPICE_MSG_CURSOR_INVAL_ONE,
SPICE_MSG_CURSOR_INVAL_ALL,
SPICE_MSG_END_CURSOR
};
static const spice_msg_handler cursor_handlers[] = {
[ SPICE_MSG_CURSOR_INIT ] = cursor_handle_init,
[ SPICE_MSG_CURSOR_RESET ] = cursor_handle_reset,
[ SPICE_MSG_CURSOR_SET ] = cursor_handle_set,
[ SPICE_MSG_CURSOR_MOVE ] = cursor_handle_move,
[ SPICE_MSG_CURSOR_HIDE ] = cursor_handle_hide,
[ SPICE_MSG_CURSOR_TRAIL ] = cursor_handle_trail,
[ SPICE_MSG_CURSOR_INVAL_ONE ] = cursor_handle_inval_one,
[ SPICE_MSG_CURSOR_INVAL_ALL ] = cursor_handle_inval_all,
};
Which I couldn't even understand what did it mean.
It couldn't pass on vc++2008,How can I change it?
That's called designated initializers which is introduced in C99. For example, to initialize an array, you can specify the array indices in any order:
int a[6] = { [4] = 29, [2] = 15 };
is equivalent to
int a[6] = { 0, 0, 15, 0, 29, 0 };
So in your example, with the definition of enums, cursor_handlers is initialized with 101 elements of 0, then several other values.
The problem is, VC++2008 doesn's support most of C99 features, including this one. So you'll have to either initialize the array with fixed order(the old C89 way), or initialize the array with all 0 and assign the appropriate elements.
Too bad the array is const, so you'll have to use the C89 way:
static const spice_msg_handler cursor_handlers[] = {0, 0, /*...all 101 0s*/, cursor_handle_init, /*...*/}
If it's not const, you can use this:
static spice_msg_handler cursor_handlers[SPICE_MSG_END_CURSOR] = {};
cursor_handlers[SPICE_MSG_CURSOR_INIT] = cursor_handle_init;
cursor_handlers[SPICE_MSG_CURSOR_RESET] = cursor_handle_reset;
//...

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