Procedure blocks (#264)

src/blocks/scratch3_procedures.js

@@ -13,7 +13,8 @@ function Scratch3ProcedureBlocks(runtime) {
 Scratch3ProcedureBlocks.prototype.getPrimitives = function() {
     return {
         'procedures_defnoreturn': this.defNoReturn,
-        'procedures_callnoreturn': this.callNoReturn
+        'procedures_callnoreturn': this.callNoReturn,
+        'procedures_param': this.param
     };
 };
 
@@ -23,10 +24,24 @@ Scratch3ProcedureBlocks.prototype.defNoReturn = function () {
 
 Scratch3ProcedureBlocks.prototype.callNoReturn = function (args, util) {
     if (!util.stackFrame.executed) {
-        var procedureName = args.mutation.name;
+        var procedureName = args.mutation.proccode;
+        var paramNames = util.getProcedureParamNames(procedureName);
+        for (var i = 0; i < paramNames.length; i++) {
+            if (args.hasOwnProperty('input' + i)) {
+                util.pushParam(paramNames[i], args['input' + i]);
+            }
+        }
         util.stackFrame.executed = true;
         util.startProcedure(procedureName);
     }
 };
 
+Scratch3ProcedureBlocks.prototype.param = function (args, util) {
+    var value = util.getParam(args.mutation.paramname);
+    if (!value) {
+        return 0;
+    }
+    return value;
+};
+
 module.exports = Scratch3ProcedureBlocks;

src/engine/blocks.js

@@ -151,13 +151,30 @@ Blocks.prototype.getProcedureDefinition = function (name) {
         var block = this._blocks[id];
         if ((block.opcode == 'procedures_defnoreturn' ||
             block.opcode == 'procedures_defreturn') &&
-            block.fields['NAME'].value == name) {
+            block.mutation.proccode == name) {
             return id;
         }
     }
     return null;
 };
 
+/**
+ * Get the procedure definition for a given name.
+ * @param {?string} name Name of procedure to query.
+ * @return {?string} ID of procedure definition.
+ */
+Blocks.prototype.getProcedureParamNames = function (name) {
+    for (var id in this._blocks) {
+        var block = this._blocks[id];
+        if ((block.opcode == 'procedures_defnoreturn' ||
+            block.opcode == 'procedures_defreturn') &&
+            block.mutation.proccode == name) {
+            return JSON.parse(block.mutation.argumentnames);
+        }
+    }
+    return null;
+};
+
 // ---------------------------------------------------------------------
 
 /**
@@ -434,7 +451,9 @@ Blocks.prototype.mutationToXML = function (mutation) {
     var mutationString = '<' + mutation.tagName;
     for (var prop in mutation) {
         if (prop == 'children' || prop == 'tagName') continue;
-        mutationString += ' ' + prop + '="' + mutation[prop] + '"';
+        var mutationValue = (typeof mutation[prop] === 'string') ?
+            xmlEscape(mutation[prop]) : mutation[prop];
+        mutationString += ' ' + prop + '="' + mutationValue + '"';
     }
     mutationString += '>';
     for (var i = 0; i < mutation.children.length; i++) {

src/engine/execute.js

@@ -164,6 +164,15 @@ var execute = function (sequencer, thread) {
         startProcedure: function (procedureName) {
             sequencer.stepToProcedure(thread, procedureName);
         },
+        getProcedureParamNames: function (procedureName) {
+            return thread.target.blocks.getProcedureParamNames(procedureName);
+        },
+        pushParam: function (paramName, paramValue) {
+            thread.pushParam(paramName, paramValue);
+        },
+        getParam: function (paramName) {
+            return thread.getParam(paramName);
+        },
         startHats: function(requestedHat, opt_matchFields, opt_target) {
             return (
                 runtime.startHats(requestedHat, opt_matchFields, opt_target)

src/engine/sequencer.js

@@ -132,6 +132,11 @@ Sequencer.prototype.stepToBranch = function (thread, branchNum) {
 Sequencer.prototype.stepToProcedure = function (thread, procedureName) {
     var definition = thread.target.blocks.getProcedureDefinition(procedureName);
     thread.pushStack(definition);
+    // Check if the call is recursive. If so, yield.
+    // @todo: Have behavior match Scratch 2.0.
+    if (thread.stack.indexOf(definition) > -1) {
+        thread.setStatus(Thread.STATUS_YIELD_FRAME);
+    }
 };
 
 /**

src/engine/thread.js

@@ -83,6 +83,7 @@ Thread.prototype.pushStack = function (blockId) {
         this.stackFrames.push({
             reported: {}, // Collects reported input values.
             waitingReporter: null, // Name of waiting reporter.
+            params: {}, // Procedure parameters.
             executionContext: {} // A context passed to block implementations.
         });
     }
@@ -135,6 +136,21 @@ Thread.prototype.pushReportedValue = function (value) {
     }
 };
 
+Thread.prototype.pushParam = function (paramName, value) {
+    var stackFrame = this.peekStackFrame();
+    stackFrame.params[paramName] = value;
+};
+
+Thread.prototype.getParam = function (paramName) {
+    for (var i = this.stackFrames.length - 1; i >= 0; i--) {
+        var frame = this.stackFrames[i];
+        if (frame.params.hasOwnProperty(paramName)) {
+            return frame.params[paramName];
+        }
+    }
+    return null;
+};
+
 /**
  * Whether the current execution of a thread is at the top of the stack.
  * @return {Boolean} True if execution is at top of the stack.

src/import/sb2import.js

@@ -203,6 +203,40 @@ function flatten (blocks) {
     return finalBlocks;
 }
 
+/**
+ * Convert a Scratch 2.0 procedure string (e.g., "my_procedure %s %b %n")
+ * into an argument map. This allows us to provide the expected inputs
+ * to a mutated procedure call.
+ * @param {string} procCode Scratch 2.0 procedure string.
+ * @return {Object} Argument map compatible with those in sb2specmap.
+ */
+function parseProcedureArgMap (procCode) {
+    var argMap = [
+        {} // First item in list is op string.
+    ];
+    var INPUT_PREFIX = 'input';
+    var inputCount = 0;
+    // Split by %n, %b, %s.
+    var parts = procCode.split(/(?=[^\\]\%[nbs])/);
+    for (var i = 0; i < parts.length; i++) {
+        var part = parts[i].trim();
+        if (part.substring(0, 1) == '%') {
+            var argType = part.substring(1, 2);
+            var arg = {
+                type: 'input',
+                inputName: INPUT_PREFIX + (inputCount++)
+            };
+            if (argType == 'n') {
+                arg.inputOp = 'math_number';
+            } else if (argType == 's') {
+                arg.inputOp = 'text';
+            }
+            argMap.push(arg);
+        }
+    }
+    return argMap;
+}
+
 /**
  * Parse a single SB2 JSON-formatted block and its children.
  * @param {!Object} sb2block SB2 JSON-formatted block.
@@ -227,6 +261,10 @@ function parseBlock (sb2block) {
         shadow: false, // No shadow blocks in an SB2 by default.
         children: [] // Store any generated children, flattened in `flatten`.
     };
+    // For a procedure call, generate argument map from proc string.
+    if (oldOpcode == 'call') {
+        blockMetadata.argMap = parseProcedureArgMap(sb2block[1]);
+    }
     // Look at the expected arguments in `blockMetadata.argMap.`
     // The basic problem here is to turn positional SB2 arguments into
     // non-positional named Scratch VM arguments.
@@ -328,11 +366,43 @@ function parseBlock (sb2block) {
         }
     }
     // Special cases to generate mutations.
-    if (oldOpcode == 'call') {
+    if (oldOpcode == 'stopScripts') {
+        // Mutation for stop block: if the argument is 'other scripts',
+        // the block needs a next connection.
+        if (sb2block[1] == 'other scripts in sprite') {
+            activeBlock.mutation = {
+                tagName: 'mutation',
+                hasnext: 'true',
+                children: []
+            };
+        }
+    } else if (oldOpcode == 'procDef') {
+        // Mutation for procedure definition:
+        // store all 2.0 proc data.
+        var procData = sb2block.slice(1);
+        activeBlock.mutation = {
+            tagName: 'mutation',
+            proccode: procData[0], // e.g., "abc %n %b %s"
+            argumentnames: JSON.stringify(procData[1]), // e.g. ['arg1', 'arg2']
+            argumentdefaults: JSON.stringify(procData[2]), // e.g., [1, 'abc']
+            warp: procData[3], // Warp mode, e.g., true/false.
+            children: []
+        };
+    } else if (oldOpcode == 'call') {
+        // Mutation for procedure call:
+        // string for proc code (e.g., "abc %n %b %s").
         activeBlock.mutation = {
             tagName: 'mutation',
             children: [],
-            name: sb2block[1]
+            proccode: sb2block[1]
+        };
+    } else if (oldOpcode == 'getParam') {
+        // Mutation for procedure parameter.
+        activeBlock.mutation = {
+            tagName: 'mutation',
+            children: [],
+            paramname: sb2block[1], // Name of parameter.
+            shape: sb2block[2] // Shape - in 2.0, 'r' or 'b'.
         };
     }
     return activeBlock;

src/import/sb2specmap.js

@@ -752,9 +752,8 @@ var specMap = {
         'opcode':'control_stop',
         'argMap':[
             {
-                'type':'input',
-                'inputOp':'control_stop_menu',
-                'inputName':'STOP_OPTION'
+                'type':'field',
+                'fieldName':'STOP_OPTION'
             }
         ]
     },
@@ -1375,15 +1374,10 @@ var specMap = {
     },
     'procDef':{
         'opcode':'procedures_defnoreturn',
-        'argMap':[
-            {
-                'type':'field',
-                'fieldName':'NAME'
-            }
-        ]
+        'argMap':[]
     },
     'getParam':{
-        'opcode':'proc_param',
+        'opcode':'procedures_param',
         'argMap':[]
     },
     'call':{