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495 lines
13 KiB
495 lines
13 KiB
import deindent from '../../utils/deindent';
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import Node from './shared/Node';
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import ElseBlock from './ElseBlock';
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import Compiler from '../Compiler';
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import Block from '../dom/Block';
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import createDebuggingComment from '../../utils/createDebuggingComment';
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import Expression from './shared/Expression';
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import mapChildren from './shared/mapChildren';
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function isElseIf(node: ElseBlock) {
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return (
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node && node.children.length === 1 && node.children[0].type === 'IfBlock'
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);
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}
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function isElseBranch(branch) {
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return branch.block && !branch.condition;
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}
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export default class IfBlock extends Node {
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type: 'IfBlock';
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expression: Expression;
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children: any[];
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else: ElseBlock;
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block: Block;
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constructor(compiler, parent, scope, info) {
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super(compiler, parent, scope, info);
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this.expression = new Expression(compiler, this, scope, info.expression);
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this.children = mapChildren(compiler, this, scope, info.children);
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this.else = info.else
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? new ElseBlock(compiler, this, scope, info.else)
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: null;
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}
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init(
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block: Block,
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stripWhitespace: boolean,
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nextSibling: Node
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) {
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const { compiler } = this;
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this.cannotUseInnerHTML();
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const blocks: Block[] = [];
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let dynamic = false;
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let hasIntros = false;
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let hasOutros = false;
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function attachBlocks(node: IfBlock) {
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node.var = block.getUniqueName(`if_block`);
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block.addDependencies(node.expression.dependencies);
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node.block = block.child({
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comment: createDebuggingComment(node, compiler),
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name: compiler.getUniqueName(`create_if_block`),
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});
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blocks.push(node.block);
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node.initChildren(node.block, stripWhitespace, nextSibling);
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if (node.block.dependencies.size > 0) {
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dynamic = true;
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block.addDependencies(node.block.dependencies);
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}
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if (node.block.hasIntroMethod) hasIntros = true;
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if (node.block.hasOutroMethod) hasOutros = true;
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if (isElseIf(node.else)) {
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attachBlocks(node.else.children[0]);
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} else if (node.else) {
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node.else.block = block.child({
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comment: createDebuggingComment(node.else, compiler),
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name: compiler.getUniqueName(`create_if_block`),
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});
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blocks.push(node.else.block);
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node.else.initChildren(
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node.else.block,
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stripWhitespace,
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nextSibling
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);
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if (node.else.block.dependencies.size > 0) {
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dynamic = true;
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block.addDependencies(node.else.block.dependencies);
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}
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}
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}
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attachBlocks(this);
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blocks.forEach(block => {
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block.hasUpdateMethod = dynamic;
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block.hasIntroMethod = hasIntros;
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block.hasOutroMethod = hasOutros;
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});
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compiler.target.blocks.push(...blocks);
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}
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build(
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block: Block,
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parentNode: string,
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parentNodes: string
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) {
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const name = this.var;
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const needsAnchor = this.next ? !this.next.isDomNode() : !parentNode || !this.parent.isDomNode();
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const anchor = needsAnchor
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? block.getUniqueName(`${name}_anchor`)
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: (this.next && this.next.var) || 'null';
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const branches = this.getBranches(block, parentNode, parentNodes, this);
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const hasElse = isElseBranch(branches[branches.length - 1]);
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const if_name = hasElse ? '' : `if (${name}) `;
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const dynamic = branches[0].hasUpdateMethod; // can use [0] as proxy for all, since they necessarily have the same value
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const hasOutros = branches[0].hasOutroMethod;
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const vars = { name, anchor, if_name, hasElse };
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if (this.else) {
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if (hasOutros) {
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this.buildCompoundWithOutros(block, parentNode, parentNodes, branches, dynamic, vars);
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} else {
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this.buildCompound(block, parentNode, parentNodes, branches, dynamic, vars);
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}
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} else {
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this.buildSimple(block, parentNode, parentNodes, branches[0], dynamic, vars);
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}
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block.builders.create.addLine(`${if_name}${name}.c();`);
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if (parentNodes) {
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block.builders.claim.addLine(
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`${if_name}${name}.l(${parentNodes});`
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);
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}
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if (needsAnchor) {
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block.addElement(
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anchor,
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`@createComment()`,
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parentNodes && `@createComment()`,
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parentNode
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);
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}
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}
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buildCompound(
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block: Block,
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parentNode: string,
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parentNodes: string,
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branches,
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dynamic,
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{ name, anchor, hasElse, if_name }
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) {
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const select_block_type = this.compiler.getUniqueName(`select_block_type`);
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const current_block_type = block.getUniqueName(`current_block_type`);
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const current_block_type_and = hasElse ? '' : `${current_block_type} && `;
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block.builders.init.addBlock(deindent`
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function ${select_block_type}(ctx) {
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${branches
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.map(({ condition, block }) => `${condition ? `if (${condition}) ` : ''}return ${block};`)
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.join('\n')}
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}
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`);
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block.builders.init.addBlock(deindent`
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var ${current_block_type} = ${select_block_type}(ctx);
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var ${name} = ${current_block_type_and}${current_block_type}(#component, ctx);
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`);
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const mountOrIntro = branches[0].hasIntroMethod ? 'i' : 'm';
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const initialMountNode = parentNode || '#target';
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const anchorNode = parentNode ? 'null' : 'anchor';
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block.builders.mount.addLine(
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`${if_name}${name}.${mountOrIntro}(${initialMountNode}, ${anchorNode});`
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);
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const updateMountNode = this.getUpdateMountNode(anchor);
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const changeBlock = deindent`
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${hasElse
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? deindent`
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${name}.d(1);
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`
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: deindent`
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if (${name}) {
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${name}.d(1);
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}`}
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${name} = ${current_block_type_and}${current_block_type}(#component, ctx);
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${if_name}${name}.c();
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${if_name}${name}.${mountOrIntro}(${updateMountNode}, ${anchor});
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`;
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if (dynamic) {
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block.builders.update.addBlock(deindent`
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if (${current_block_type} === (${current_block_type} = ${select_block_type}(ctx)) && ${name}) {
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${name}.p(changed, ctx);
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} else {
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${changeBlock}
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}
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`);
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} else {
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block.builders.update.addBlock(deindent`
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if (${current_block_type} !== (${current_block_type} = ${select_block_type}(ctx))) {
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${changeBlock}
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}
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`);
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}
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block.builders.destroy.addLine(`${if_name}${name}.d(${parentNode ? '' : 'detach'});`);
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}
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// if any of the siblings have outros, we need to keep references to the blocks
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// (TODO does this only apply to bidi transitions?)
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buildCompoundWithOutros(
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block: Block,
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parentNode: string,
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parentNodes: string,
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branches,
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dynamic,
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{ name, anchor, hasElse }
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) {
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const select_block_type = block.getUniqueName(`select_block_type`);
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const current_block_type_index = block.getUniqueName(`current_block_type_index`);
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const previous_block_index = block.getUniqueName(`previous_block_index`);
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const if_block_creators = block.getUniqueName(`if_block_creators`);
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const if_blocks = block.getUniqueName(`if_blocks`);
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const if_current_block_type_index = hasElse
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? ''
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: `if (~${current_block_type_index}) `;
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block.addVariable(current_block_type_index);
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block.addVariable(name);
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block.builders.init.addBlock(deindent`
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var ${if_block_creators} = [
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${branches.map(branch => branch.block).join(',\n')}
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];
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var ${if_blocks} = [];
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function ${select_block_type}(ctx) {
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${branches
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.map(({ condition, block }, i) => `${condition ? `if (${condition}) ` : ''}return ${block ? i : -1};`)
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.join('\n')}
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}
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`);
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if (hasElse) {
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block.builders.init.addBlock(deindent`
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${current_block_type_index} = ${select_block_type}(ctx);
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${name} = ${if_blocks}[${current_block_type_index}] = ${if_block_creators}[${current_block_type_index}](#component, ctx);
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`);
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} else {
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block.builders.init.addBlock(deindent`
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if (~(${current_block_type_index} = ${select_block_type}(ctx))) {
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${name} = ${if_blocks}[${current_block_type_index}] = ${if_block_creators}[${current_block_type_index}](#component, ctx);
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}
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`);
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}
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const mountOrIntro = branches[0].hasIntroMethod ? 'i' : 'm';
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const initialMountNode = parentNode || '#target';
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const anchorNode = parentNode ? 'null' : 'anchor';
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block.builders.mount.addLine(
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`${if_current_block_type_index}${if_blocks}[${current_block_type_index}].${mountOrIntro}(${initialMountNode}, ${anchorNode});`
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);
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const updateMountNode = this.getUpdateMountNode(anchor);
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const destroyOldBlock = deindent`
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${name}.o(function() {
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${if_blocks}[ ${previous_block_index} ].d(1);
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${if_blocks}[ ${previous_block_index} ] = null;
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});
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`;
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const createNewBlock = deindent`
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${name} = ${if_blocks}[${current_block_type_index}];
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if (!${name}) {
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${name} = ${if_blocks}[${current_block_type_index}] = ${if_block_creators}[${current_block_type_index}](#component, ctx);
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${name}.c();
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}
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${name}.${mountOrIntro}(${updateMountNode}, ${anchor});
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`;
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const changeBlock = hasElse
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? deindent`
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${destroyOldBlock}
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${createNewBlock}
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`
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: deindent`
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if (${name}) {
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${destroyOldBlock}
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}
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if (~${current_block_type_index}) {
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${createNewBlock}
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} else {
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${name} = null;
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}
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`;
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if (dynamic) {
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block.builders.update.addBlock(deindent`
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var ${previous_block_index} = ${current_block_type_index};
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${current_block_type_index} = ${select_block_type}(ctx);
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if (${current_block_type_index} === ${previous_block_index}) {
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${if_current_block_type_index}${if_blocks}[${current_block_type_index}].p(changed, ctx);
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} else {
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${changeBlock}
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}
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`);
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} else {
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block.builders.update.addBlock(deindent`
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var ${previous_block_index} = ${current_block_type_index};
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${current_block_type_index} = ${select_block_type}(ctx);
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if (${current_block_type_index} !== ${previous_block_index}) {
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${changeBlock}
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}
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`);
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}
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block.builders.destroy.addLine(deindent`
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${if_current_block_type_index}{
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${if_blocks}[${current_block_type_index}].d(${parentNode ? '' : 'detach'});
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}
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`);
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}
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buildSimple(
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block: Block,
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parentNode: string,
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parentNodes: string,
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branch,
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dynamic,
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{ name, anchor, if_name }
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) {
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block.builders.init.addBlock(deindent`
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var ${name} = (${branch.condition}) && ${branch.block}(#component, ctx);
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`);
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const mountOrIntro = branch.hasIntroMethod ? 'i' : 'm';
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const initialMountNode = parentNode || '#target';
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const anchorNode = parentNode ? 'null' : 'anchor';
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block.builders.mount.addLine(
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`if (${name}) ${name}.${mountOrIntro}(${initialMountNode}, ${anchorNode});`
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);
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const updateMountNode = this.getUpdateMountNode(anchor);
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const enter = dynamic
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? branch.hasIntroMethod
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? deindent`
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if (${name}) {
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${name}.p(changed, ctx);
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} else {
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${name} = ${branch.block}(#component, ctx);
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if (${name}) ${name}.c();
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}
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${name}.i(${updateMountNode}, ${anchor});
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`
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: deindent`
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if (${name}) {
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${name}.p(changed, ctx);
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} else {
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${name} = ${branch.block}(#component, ctx);
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${name}.c();
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${name}.m(${updateMountNode}, ${anchor});
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}
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`
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: branch.hasIntroMethod
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? deindent`
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if (!${name}) {
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${name} = ${branch.block}(#component, ctx);
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${name}.c();
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}
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${name}.i(${updateMountNode}, ${anchor});
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`
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: deindent`
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if (!${name}) {
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${name} = ${branch.block}(#component, ctx);
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${name}.c();
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${name}.m(${updateMountNode}, ${anchor});
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}
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`;
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// no `p()` here — we don't want to update outroing nodes,
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// as that will typically result in glitching
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const exit = branch.hasOutroMethod
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? deindent`
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${name}.o(function() {
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${name}.d(1);
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${name} = null;
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});
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`
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: deindent`
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${name}.d(1);
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${name} = null;
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`;
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block.builders.update.addBlock(deindent`
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if (${branch.condition}) {
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${enter}
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} else if (${name}) {
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${exit}
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}
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`);
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block.builders.destroy.addLine(`${if_name}${name}.d(${parentNode ? '' : 'detach'});`);
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}
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getBranches(
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block: Block,
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parentNode: string,
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parentNodes: string,
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node: IfBlock
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) {
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const branches = [
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{
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condition: node.expression.snippet,
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block: node.block.name,
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hasUpdateMethod: node.block.hasUpdateMethod,
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hasIntroMethod: node.block.hasIntroMethod,
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hasOutroMethod: node.block.hasOutroMethod,
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},
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];
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this.visitChildren(block, node);
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if (isElseIf(node.else)) {
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branches.push(
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...this.getBranches(block, parentNode, parentNodes, node.else.children[0])
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);
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} else {
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branches.push({
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condition: null,
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block: node.else ? node.else.block.name : null,
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hasUpdateMethod: node.else ? node.else.block.hasUpdateMethod : false,
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hasIntroMethod: node.else ? node.else.block.hasIntroMethod : false,
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hasOutroMethod: node.else ? node.else.block.hasOutroMethod : false,
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});
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if (node.else) {
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this.visitChildren(block, node.else);
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}
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}
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return branches;
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}
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ssr() {
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const { compiler } = this;
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const { snippet } = this.expression;
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compiler.target.append('${ ' + snippet + ' ? `');
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this.children.forEach((child: Node) => {
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child.ssr();
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});
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compiler.target.append('` : `');
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if (this.else) {
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this.else.children.forEach((child: Node) => {
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child.ssr();
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});
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}
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compiler.target.append('` }');
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}
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visitChildren(block: Block, node: Node) {
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node.children.forEach((child: Node) => {
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child.build(node.block, null, 'nodes');
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});
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}
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} |