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General-purpose hat implementation

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This commit is contained in:
Tim Mickel 2016-08-23 18:12:32 -04:00
parent 39fdbaf983
commit b4cf64009f
2 changed files with 232 additions and 46 deletions
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105
src/engine/execute.js
View file

@ -1,5 +1,14 @@
var Thread = require('./thread');
/**
* Utility function to determine if a value is a Promise.
* @param {*} value Value to check for a Promise.
* @return {Boolean} True if the value appears to be a Promise.
*/
var isPromise = function (value) {
return value && value.then && typeof value.then === 'function';
};
/**
* Execute a block.
* @param {!Sequencer} sequencer Which sequencer is executing.
@ -21,9 +30,28 @@ var execute = function (sequencer, thread) {
}
var blockFunction = runtime.getOpcodeFunction(opcode);
if (!blockFunction) {
console.warn('Could not get implementation for opcode: ' + opcode);
return;
var isHat = runtime.getIsHat(opcode);
// Hats are implemented slightly differently from regular blocks.
// If they have an associated block function, it's treated as a predicate;
// if not, execution will proceed right through it (as a no-op).
if (isHat) {
var nextBlock = target.blocks.getNextBlock(currentBlockId);
if (!nextBlock) {
// Hat with no next block - don't try to evaluate it.
sequencer.retireThread(thread);
return;
}
if (!blockFunction) {
// No predicate for the hat - just continue to next block.
sequencer.proceedThread(thread);
return;
}
} else {
if (!blockFunction) {
console.warn('Could not get implementation for opcode: ' + opcode);
return;
}
}
// Generate values for arguments (inputs).
@ -63,6 +91,8 @@ var execute = function (sequencer, thread) {
var primitiveReportedValue = null;
primitiveReportedValue = blockFunction(argValues, {
stackFrame: currentStackFrame.executionContext,
target: target,
yield: function() {
thread.setStatus(Thread.STATUS_YIELD);
},
@ -73,11 +103,14 @@ var execute = function (sequencer, thread) {
thread.setStatus(Thread.STATUS_RUNNING);
sequencer.proceedThread(thread);
},
stackFrame: currentStackFrame.executionContext,
startBranch: function (branchNum) {
sequencer.stepToBranch(thread, branchNum);
},
target: target,
triggerHats: function(requestedHat, opt_matchFields, opt_target) {
return (
runtime.triggerHats(requestedHat, opt_matchFields, opt_target)
);
},
ioQuery: function (device, func, args) {
// Find the I/O device and execute the query/function call.
if (runtime.ioDevices[device] && runtime.ioDevices[device][func]) {
@ -87,28 +120,53 @@ var execute = function (sequencer, thread) {
}
});
// Deal with any reported value.
/**
* Handle any reported value from the primitive, either directly returned
* or after a promise resolves.
* @param {*} resolvedValue Value eventually returned from the primitive.
*/
var handleReport = function (resolvedValue) {
thread.pushReportedValue(resolvedValue);
if (isHat) {
// Hat predicate was evaluated.
if (runtime.getIsEdgeTriggeredHat(opcode)) {
// If this is an edge-triggered hat, only proceed if
// the value is true and used to be false.
var oldEdgeValue = runtime.updateEdgeTriggeredValue(
currentBlockId,
resolvedValue
);
var edgeWasTriggered = !oldEdgeValue && resolvedValue;
if (!edgeWasTriggered) {
sequencer.retireThread(thread);
}
} else {
// Not an edge-triggered hat: retire the thread
// if predicate was false.
if (!resolvedValue) {
sequencer.retireThread(thread);
}
}
} else {
// In a non-hat, report the value visually if necessary if
// at the top of the thread stack.
if (typeof resolvedValue !== 'undefined' && thread.atStackTop()) {
runtime.visualReport(currentBlockId, resolvedValue);
}
// Finished any yields.
thread.setStatus(Thread.STATUS_RUNNING);
}
};
// If it's a promise, wait until promise resolves.
var isPromise = (
primitiveReportedValue &&
primitiveReportedValue.then &&
typeof primitiveReportedValue.then === 'function'
);
if (isPromise) {
if (isPromise(primitiveReportedValue)) {
if (thread.status === Thread.STATUS_RUNNING) {
// Primitive returned a promise; automatically yield thread.
thread.setStatus(Thread.STATUS_YIELD);
}
// Promise handlers
primitiveReportedValue.then(function(resolvedValue) {
// Promise resolved: the primitive reported a value.
thread.pushReportedValue(resolvedValue);
// Report the value visually if necessary.
if (typeof resolvedValue !== 'undefined' &&
thread.peekStack() === thread.topBlock) {
runtime.visualReport(thread.peekStack(), resolvedValue);
}
thread.setStatus(Thread.STATUS_RUNNING);
handleReport(resolvedValue);
sequencer.proceedThread(thread);
}, function(rejectionReason) {
// Promise rejected: the primitive had some error.
@ -118,12 +176,7 @@ var execute = function (sequencer, thread) {
sequencer.proceedThread(thread);
});
} else if (thread.status === Thread.STATUS_RUNNING) {
thread.pushReportedValue(primitiveReportedValue);
// Report the value visually if necessary.
if (typeof primitiveReportedValue !== 'undefined' &&
thread.peekStack() === thread.topBlock) {
runtime.visualReport(thread.peekStack(), primitiveReportedValue);
}
handleReport(primitiveReportedValue);
}
};

173
src/engine/runtime.js
View file

@ -47,6 +47,8 @@ function Runtime (targets) {
* @type {Object.<string, Function>}
*/
this._primitives = {};
this._hats = {};
this._edgeTriggeredHatValues = {};
this._registerBlockPackages();
this.ioDevices = {
@ -109,11 +111,23 @@ Runtime.prototype._registerBlockPackages = function () {
if (defaultBlockPackages.hasOwnProperty(packageName)) {
// @todo pass a different runtime depending on package privilege?
var packageObject = new (defaultBlockPackages[packageName])(this);
var packageContents = packageObject.getPrimitives();
for (var op in packageContents) {
if (packageContents.hasOwnProperty(op)) {
this._primitives[op] =
packageContents[op].bind(packageObject);
// Collect primitives from package.
if (packageObject.getPrimitives) {
var packagePrimitives = packageObject.getPrimitives();
for (var op in packagePrimitives) {
if (packagePrimitives.hasOwnProperty(op)) {
this._primitives[op] =
packagePrimitives[op].bind(packageObject);
}
}
}
// Collect hat metadata from package.
if (packageObject.getHats) {
var packageHats = packageObject.getHats();
for (var hatName in packageHats) {
if (packageHats.hasOwnProperty(hatName)) {
this._hats[hatName] = packageHats[hatName];
}
}
}
}
@ -132,6 +146,46 @@ Runtime.prototype.getOpcodeFunction = function (opcode) {
// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------
/**
* Return whether an opcode represents a hat block.
* @param {!string} opcode The opcode to look up.
* @return {Boolean} True if the op is known to be a hat.
*/
Runtime.prototype.getIsHat = function (opcode) {
return opcode in this._hats;
};
/**
* Return whether an opcode represents an edge-triggered hat block.
* @param {!string} opcode The opcode to look up.
* @return {Boolean} True if the op is known to be a edge-triggered hat.
*/
Runtime.prototype.getIsEdgeTriggeredHat = function (opcode) {
return opcode in this._hats && this._hats[opcode].edgeTriggered;
};
/**
* Update an edge-triggered hat block value.
* @param {!string} blockId ID of hat to store value for.
* @param {*} newValue Value to store for edge-triggered hat.
* @return {*} The old value for the edge-triggered hat.
*/
Runtime.prototype.updateEdgeTriggeredValue = function (blockId, newValue) {
var oldValue = this._edgeTriggeredHatValues[blockId];
this._edgeTriggeredHatValues[blockId] = newValue;
return oldValue;
};
/**
* Clear all edge-triggered hat values.
*/
Runtime.prototype.clearEdgeTriggeredValues = function () {
this._edgeTriggeredHatValues = {};
};
// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------
/**
* Create a thread and push it to the list of threads.
* @param {!string} id ID of block that starts the stack
@ -150,6 +204,7 @@ Runtime.prototype._pushThread = function (id) {
* @param {?Thread} thread Thread object to remove from actives
*/
Runtime.prototype._removeThread = function (thread) {
thread.setStatus(Thread.STATUS_DONE);
var i = this.threads.indexOf(thread);
if (i > -1) {
this.glowScript(thread.topBlock, false);
@ -174,28 +229,99 @@ Runtime.prototype.toggleScript = function (topBlockId) {
};
/**
* Green flag, which stops currently running threads
* and adds all top-level scripts that start with the green flag
* Run a function `f` for all scripts in a workspace.
* `f` will be called with two parameters:
* -the top block ID of each script
* -the opcode of that block, for convenience.
* -fields on that block, for convenience.
* @param {!Function} f Function to call for each script.
* @param {Target=} opt_target Optionally, a target to restrict to.
*/
Runtime.prototype.greenFlag = function () {
// Remove all existing threads
for (var i = 0; i < this.threads.length; i++) {
this._removeThread(this.threads[i]);
Runtime.prototype.allScriptsDo = function (f, opt_target) {
var targets = this.targets;
if (opt_target) {
targets = [opt_target];
}
// Add all top scripts with green flag
for (var t = 0; t < this.targets.length; t++) {
var target = this.targets[t];
for (var t = 0; t < targets.length; t++) {
var target = targets[t];
var scripts = target.blocks.getScripts();
for (var j = 0; j < scripts.length; j++) {
var topBlock = scripts[j];
if (target.blocks.getBlock(topBlock).opcode ===
'event_whenflagclicked') {
this._pushThread(scripts[j]);
}
var topOpcode = target.blocks.getBlock(topBlock).opcode;
var topFields = target.blocks.getFields(topBlock);
f(topBlock, topOpcode, topFields);
}
}
};
/**
* Trigger all relevant hats.
* @param {!string} requestedHat Name of hat to trigger.
* @param {Object=} opt_matchFields Optionally, fields to match on the hat.
* @param {Target=} opt_target Optionally, a target to restrict to.
* @return {Array.<Thread>} List of threads started by this trigger.
*/
Runtime.prototype.triggerHats = function (requestedHat,
opt_matchFields, opt_target) {
var instance = this;
var newThreads = [];
// Consider all scripts, looking for hats named `requestedHat`.
this.allScriptsDo(function(topBlockId, topOpcode, topFields) {
if (topOpcode !== requestedHat) {
// Not the right hat.
return;
}
// Match any requested fields.
// For example: ensures that broadcasts match.
// This needs to happen before the block is evaluated
// (i.e., before the predicate can be run) because "broadcast and wait"
// needs to have a precise collection of triggered threads.
if (opt_matchFields) {
for (var matchField in opt_matchFields) {
if (topFields[matchField].value !==
opt_matchFields[matchField]) {
// Field mismatch.
return;
}
}
}
if (instance._hats.hasOwnProperty(topOpcode)) {
// Look up metadata for the relevant hat.
var hatMeta = instance._hats[topOpcode];
if (hatMeta.restartExistingThreads) {
// If `restartExistingThreads` is true, this trigger
// should stop any existing threads starting with the top block.
for (var i = 0; i < instance.threads.length; i++) {
if (instance.threads[i].topBlock === topBlockId) {
instance._removeThread(instance.threads[i]);
}
}
} else {
// If `restartExistingThreads` is false, this trigger
// should give up if any threads with the top block are running.
for (var j = 0; j < instance.threads.length; j++) {
if (instance.threads[j].topBlock === topBlockId) {
// Some thread is already running.
return;
}
}
}
// Start the thread with this top block.
newThreads.push(instance._pushThread(topBlockId));
}
}, opt_target);
return newThreads;
};
/**
* Start all threads that start with the green flag.
*/
Runtime.prototype.greenFlag = function () {
this.ioDevices.clock.resetProjectTimer();
this.clearEdgeTriggeredValues();
this.triggerHats('event_whenflagclicked');
};
/**
* Stop "everything"
*/
@ -217,9 +343,16 @@ Runtime.prototype.stopAll = function () {
* inactive threads after each iteration.
*/
Runtime.prototype._step = function () {
// Find all edge-triggered hats, and add them to threads to be evaluated.
for (var hatType in this._hats) {
var hat = this._hats[hatType];
if (hat.edgeTriggered) {
this.triggerHats(hatType);
}
}
var inactiveThreads = this.sequencer.stepThreads(this.threads);
for (var i = 0; i < inactiveThreads.length; i++) {
this._removeThread(inactiveThreads[i]);
for (var j = 0; j < inactiveThreads.length; j++) {
this._removeThread(inactiveThreads[j]);
}
};