Improve rules around when parallel stages are allowed [#11]

lib/sequence-diagram-web.js

@@ -1677,6 +1677,19 @@
 	}
 
 	function checkReferenceConflicts(allStages) {
+		const count = allStages
+			.filter((stage) => (
+				stage.type === 'block begin' ||
+				stage.type === 'block end'
+			))
+			.length;
+
+		if(!count) {
+			return null;
+		} else if(count !== allStages.length) {
+			return 'Cannot use parallel here';
+		}
+
 		const leftIDs = allStages
 			.filter((stage) => (stage.type === 'block begin'))
 			.map((stage) => stage.left);
@@ -1708,6 +1721,21 @@
 		return null;
 	}
 
+	const PARALLEL_STAGES = [
+		'agent begin',
+		'agent end',
+		'agent highlight',
+		'block begin',
+		'block end',
+		'connect',
+		'connect-delay-begin',
+		'connect-delay-end',
+		'note over',
+		'note right',
+		'note left',
+		'note between',
+	];
+
 	function errorForParallel(existing, latest) {
 		if(!existing) {
 			return 'Nothing to run statement in parallel with';
@@ -1717,6 +1745,9 @@
 		extractParallel(allStages, [existing]);
 		extractParallel(allStages, [latest]);
 
+		if(allStages.some((stage) => !PARALLEL_STAGES.includes(stage.type))) {
+			return 'Cannot use parallel here';
+		}
 		return (
 			checkAgentConflicts(allStages) ||
 			checkReferenceConflicts(allStages) ||
@@ -1875,7 +1906,7 @@
 			const {stages} = this.currentSection;
 			if(parallel) {
 				const target = stages[stages.length - 2];
-				if(!target) {
+				if(stages.length === 0) {
 					throw new Error('Nothing to run statement in parallel with');
 				}
 				if(errorForParallel(target, stage)) {
@@ -2085,7 +2116,10 @@
 			return name;
 		}
 
-		handleBlockBegin({ln, blockType, tag, label}) {
+		handleBlockBegin({ln, blockType, tag, label, parallel}) {
+			if(parallel) {
+				throw new Error('Cannot use parallel here');
+			}
 			this.beginNested(blockType, {
 				label,
 				ln,
@@ -2094,7 +2128,10 @@
 			});
 		}
 
-		handleBlockSplit({ln, blockType, tag, label}) {
+		handleBlockSplit({ln, blockType, tag, label, parallel}) {
+			if(parallel) {
+				throw new Error('Cannot use parallel here');
+			}
 			if(this.currentNest.blockType !== 'if') {
 				throw new Error(
 					'Invalid block nesting ("else" inside ' +
@@ -2114,7 +2151,7 @@
 			this.currentNest.sections.push(this.currentSection);
 		}
 
-		handleBlockEnd() {
+		handleBlockEnd({parallel}) {
 			if(this.nesting.length <= 1) {
 				throw new Error('Invalid block nesting (too many "end"s)');
 			}
@@ -2142,7 +2179,7 @@
 				left: nested.leftGAgent.id,
 				right: nested.rightGAgent.id,
 				type: 'block end',
-			});
+			}, {parallel});
 		}
 
 		makeGroupDetails(pAgents, alias) {
@@ -2231,25 +2268,25 @@
 			};
 		}
 
-		handleMark({name}) {
+		handleMark({name, parallel}) {
 			this.markers.add(name);
-			this.addStage({name, type: 'mark'}, {isVisible: false});
+			this.addStage({name, type: 'mark'}, {isVisible: false, parallel});
 		}
 
-		handleDivider({mode, height, label}) {
+		handleDivider({mode, height, label, parallel}) {
 			this.addStage({
 				formattedLabel: this.textFormatter(label),
 				height,
 				mode,
 				type: 'divider',
-			}, {isVisible: false});
+			}, {isVisible: false, parallel});
 		}
 
-		handleAsync({target}) {
+		handleAsync({target, parallel}) {
 			if(target !== '' && !this.markers.has(target)) {
 				throw new Error('Unknown marker: ' + target);
 			}
-			this.addStage({target, type: 'async'}, {isVisible: false});
+			this.addStage({target, type: 'async'}, {isVisible: false, parallel});
 		}
 
 		handleLabelPattern({pattern}) {

lib/sequence-diagram.js

@@ -1677,6 +1677,19 @@
 	}
 
 	function checkReferenceConflicts(allStages) {
+		const count = allStages
+			.filter((stage) => (
+				stage.type === 'block begin' ||
+				stage.type === 'block end'
+			))
+			.length;
+
+		if(!count) {
+			return null;
+		} else if(count !== allStages.length) {
+			return 'Cannot use parallel here';
+		}
+
 		const leftIDs = allStages
 			.filter((stage) => (stage.type === 'block begin'))
 			.map((stage) => stage.left);
@@ -1708,6 +1721,21 @@
 		return null;
 	}
 
+	const PARALLEL_STAGES = [
+		'agent begin',
+		'agent end',
+		'agent highlight',
+		'block begin',
+		'block end',
+		'connect',
+		'connect-delay-begin',
+		'connect-delay-end',
+		'note over',
+		'note right',
+		'note left',
+		'note between',
+	];
+
 	function errorForParallel(existing, latest) {
 		if(!existing) {
 			return 'Nothing to run statement in parallel with';
@@ -1717,6 +1745,9 @@
 		extractParallel(allStages, [existing]);
 		extractParallel(allStages, [latest]);
 
+		if(allStages.some((stage) => !PARALLEL_STAGES.includes(stage.type))) {
+			return 'Cannot use parallel here';
+		}
 		return (
 			checkAgentConflicts(allStages) ||
 			checkReferenceConflicts(allStages) ||
@@ -1875,7 +1906,7 @@
 			const {stages} = this.currentSection;
 			if(parallel) {
 				const target = stages[stages.length - 2];
-				if(!target) {
+				if(stages.length === 0) {
 					throw new Error('Nothing to run statement in parallel with');
 				}
 				if(errorForParallel(target, stage)) {
@@ -2085,7 +2116,10 @@
 			return name;
 		}
 
-		handleBlockBegin({ln, blockType, tag, label}) {
+		handleBlockBegin({ln, blockType, tag, label, parallel}) {
+			if(parallel) {
+				throw new Error('Cannot use parallel here');
+			}
 			this.beginNested(blockType, {
 				label,
 				ln,
@@ -2094,7 +2128,10 @@
 			});
 		}
 
-		handleBlockSplit({ln, blockType, tag, label}) {
+		handleBlockSplit({ln, blockType, tag, label, parallel}) {
+			if(parallel) {
+				throw new Error('Cannot use parallel here');
+			}
 			if(this.currentNest.blockType !== 'if') {
 				throw new Error(
 					'Invalid block nesting ("else" inside ' +
@@ -2114,7 +2151,7 @@
 			this.currentNest.sections.push(this.currentSection);
 		}
 
-		handleBlockEnd() {
+		handleBlockEnd({parallel}) {
 			if(this.nesting.length <= 1) {
 				throw new Error('Invalid block nesting (too many "end"s)');
 			}
@@ -2142,7 +2179,7 @@
 				left: nested.leftGAgent.id,
 				right: nested.rightGAgent.id,
 				type: 'block end',
-			});
+			}, {parallel});
 		}
 
 		makeGroupDetails(pAgents, alias) {
@@ -2231,25 +2268,25 @@
 			};
 		}
 
-		handleMark({name}) {
+		handleMark({name, parallel}) {
 			this.markers.add(name);
-			this.addStage({name, type: 'mark'}, {isVisible: false});
+			this.addStage({name, type: 'mark'}, {isVisible: false, parallel});
 		}
 
-		handleDivider({mode, height, label}) {
+		handleDivider({mode, height, label, parallel}) {
 			this.addStage({
 				formattedLabel: this.textFormatter(label),
 				height,
 				mode,
 				type: 'divider',
-			}, {isVisible: false});
+			}, {isVisible: false, parallel});
 		}
 
-		handleAsync({target}) {
+		handleAsync({target, parallel}) {
 			if(target !== '' && !this.markers.has(target)) {
 				throw new Error('Unknown marker: ' + target);
 			}
-			this.addStage({target, type: 'async'}, {isVisible: false});
+			this.addStage({target, type: 'async'}, {isVisible: false, parallel});
 		}
 
 		handleLabelPattern({pattern}) {

scripts/sequence/generator/Generator.mjs

@@ -227,6 +227,19 @@ function checkAgentConflicts(allStages) {
 }
 
 function checkReferenceConflicts(allStages) {
+	const count = allStages
+		.filter((stage) => (
+			stage.type === 'block begin' ||
+			stage.type === 'block end'
+		))
+		.length;
+
+	if(!count) {
+		return null;
+	} else if(count !== allStages.length) {
+		return 'Cannot use parallel here';
+	}
+
 	const leftIDs = allStages
 		.filter((stage) => (stage.type === 'block begin'))
 		.map((stage) => stage.left);
@@ -258,6 +271,21 @@ function checkDelayedConflicts(allStages) {
 	return null;
 }
 
+const PARALLEL_STAGES = [
+	'agent begin',
+	'agent end',
+	'agent highlight',
+	'block begin',
+	'block end',
+	'connect',
+	'connect-delay-begin',
+	'connect-delay-end',
+	'note over',
+	'note right',
+	'note left',
+	'note between',
+];
+
 function errorForParallel(existing, latest) {
 	if(!existing) {
 		return 'Nothing to run statement in parallel with';
@@ -267,6 +295,9 @@ function errorForParallel(existing, latest) {
 	extractParallel(allStages, [existing]);
 	extractParallel(allStages, [latest]);
 
+	if(allStages.some((stage) => !PARALLEL_STAGES.includes(stage.type))) {
+		return 'Cannot use parallel here';
+	}
 	return (
 		checkAgentConflicts(allStages) ||
 		checkReferenceConflicts(allStages) ||
@@ -425,7 +456,7 @@ export default class Generator {
 		const {stages} = this.currentSection;
 		if(parallel) {
 			const target = stages[stages.length - 2];
-			if(!target) {
+			if(stages.length === 0) {
 				throw new Error('Nothing to run statement in parallel with');
 			}
 			if(errorForParallel(target, stage)) {
@@ -635,7 +666,10 @@ export default class Generator {
 		return name;
 	}
 
-	handleBlockBegin({ln, blockType, tag, label}) {
+	handleBlockBegin({ln, blockType, tag, label, parallel}) {
+		if(parallel) {
+			throw new Error('Cannot use parallel here');
+		}
 		this.beginNested(blockType, {
 			label,
 			ln,
@@ -644,7 +678,10 @@ export default class Generator {
 		});
 	}
 
-	handleBlockSplit({ln, blockType, tag, label}) {
+	handleBlockSplit({ln, blockType, tag, label, parallel}) {
+		if(parallel) {
+			throw new Error('Cannot use parallel here');
+		}
 		if(this.currentNest.blockType !== 'if') {
 			throw new Error(
 				'Invalid block nesting ("else" inside ' +
@@ -664,7 +701,7 @@ export default class Generator {
 		this.currentNest.sections.push(this.currentSection);
 	}
 
-	handleBlockEnd() {
+	handleBlockEnd({parallel}) {
 		if(this.nesting.length <= 1) {
 			throw new Error('Invalid block nesting (too many "end"s)');
 		}
@@ -692,7 +729,7 @@ export default class Generator {
 			left: nested.leftGAgent.id,
 			right: nested.rightGAgent.id,
 			type: 'block end',
-		});
+		}, {parallel});
 	}
 
 	makeGroupDetails(pAgents, alias) {
@@ -781,25 +818,25 @@ export default class Generator {
 		};
 	}
 
-	handleMark({name}) {
+	handleMark({name, parallel}) {
 		this.markers.add(name);
-		this.addStage({name, type: 'mark'}, {isVisible: false});
+		this.addStage({name, type: 'mark'}, {isVisible: false, parallel});
 	}
 
-	handleDivider({mode, height, label}) {
+	handleDivider({mode, height, label, parallel}) {
 		this.addStage({
 			formattedLabel: this.textFormatter(label),
 			height,
 			mode,
 			type: 'divider',
-		}, {isVisible: false});
+		}, {isVisible: false, parallel});
 	}
 
-	handleAsync({target}) {
+	handleAsync({target, parallel}) {
 		if(target !== '' && !this.markers.has(target)) {
 			throw new Error('Unknown marker: ' + target);
 		}
-		this.addStage({target, type: 'async'}, {isVisible: false});
+		this.addStage({target, type: 'async'}, {isVisible: false, parallel});
 	}
 
 	handleLabelPattern({pattern}) {

scripts/sequence/generator/Generator_spec.mjs

@@ -2125,6 +2125,28 @@ describe('Sequence Generator', () => {
 			]);
 		});
 
+		it('adds implicit stages for parallel actions', () => {
+			const sequence = invoke([
+				PARSED.beginAgents(['A']),
+				PARSED.blockBegin('tag', ''),
+				PARSED.note('note over', ['A']),
+				PARSED.connect(['A', 'B'], {parallel: true}),
+				PARSED.blockEnd(),
+			]);
+
+			expect(sequence.stages).toEqual([
+				any(),
+				any(),
+				GENERATED.beginAgents(['B']),
+				GENERATED.parallel([
+					GENERATED.note('note over', ['A']),
+					GENERATED.connect(['A', 'B']),
+				]),
+				any(),
+				any(),
+			]);
+		});
+
 		it('combines parallel connects and implicit begins', () => {
 			const sequence = invoke([
 				PARSED.connect(['A', 'B']),
@@ -2231,6 +2253,42 @@ describe('Sequence Generator', () => {
 			));
 		});
 
+		it('rejects using parallel with mixed actions', () => {
+			expect(() => invoke([
+				PARSED.connect(['A', 'B']),
+				{type: 'mark', name: 'foo', ln: 0, parallel: true},
+			])).toThrow(new Error(
+				'Cannot use parallel here at line 1'
+			));
+
+			expect(() => invoke([
+				{type: 'mark', name: 'foo', ln: 0},
+				PARSED.connect(['A', 'B'], {parallel: true}),
+			])).toThrow(new Error(
+				'Cannot use parallel here at line 1'
+			));
+		});
+
+		it('rejects using parallel with restricted actions', () => {
+			expect(() => invoke([
+				PARSED.connect(['A', 'B']),
+				PARSED.blockBegin('tag', '', {parallel: true}),
+				PARSED.connect(['A', 'B']),
+				PARSED.blockEnd(),
+			])).toThrow(new Error(
+				'Cannot use parallel here at line 1'
+			));
+
+			expect(() => invoke([
+				PARSED.blockBegin('tag', ''),
+				PARSED.connect(['A', 'B']),
+				PARSED.blockEnd(),
+				PARSED.connect(['A', 'B'], {parallel: true}),
+			])).toThrow(new Error(
+				'Cannot use parallel here at line 1'
+			));
+		});
+
 		it('rejects note between with a repeated agent', () => {
 			expect(() => invoke([
 				PARSED.note('note between', ['A', 'A'], {