walt-compiler

<!doctype html> <html lang="en"> <head> <title>Code coverage report for src/syntax-sugar/default-arguments.js</title> <meta charset="utf-8" /> <link rel="stylesheet" href="../../prettify.css" /> <link rel="stylesheet" href="../../base.css" /> <meta name="viewport" content="width=device-width, initial-scale=1"> <style type='text/css'> .coverage-summary .sorter { background-image: url(../../sort-arrow-sprite.png); } </style> </head> <body> <div class='wrapper'> <div class='pad1'> <h1> <a href="../../index.html">All files</a> / <a href="index.html">src/syntax-sugar</a> default-arguments.js </h1> <div class='clearfix'> <div class='fl pad1y space-right2'> 100% Statements 26/26 </div> <div class='fl pad1y space-right2'> 100% Branches 4/4 </div> <div class='fl pad1y space-right2'> 100% Functions 5/5 </div> <div class='fl pad1y space-right2'> 100% Lines 26/26 </div> </div> </div> <div class='status-line high'></div> <pre><table class="coverage"> <tr><td class="line-count quiet">1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103</td><td class="line-coverage quiet">              23x   23x 23x       90x     90x 90x 173x 173x   173x   173x   2x 2x           173x                                                                   90x 706x 706x 706x   706x     706x 460x       246x 246x 246x 246x 2x                       244x            </td><td class="text"><pre class="prettyprint lang-js">/** * Default Arguments syntax sugar plugin. * * Converts FUNCTION CALLS with missing arguments to default values * * @flow */ import Syntax from 'walt-syntax'; // $FlowFixMe import grammar from './default-arguments.ne'; import walkNode from 'walt-parser-tools/walk-node'; import type { SemanticPlugin, GrammarPlugin } from '../flow/types';   export default function(): SemanticPlugin & GrammarPlugin { return { grammar, semantics() { return { [Syntax.FunctionDeclaration]: next => args => { const [node, context] = args; const [argumentsNode] = node.params;   const defaultArguments = [];   walkNode({ Assignment: defaultArg => { const [, value] = defaultArg.params; defaultArguments.push(value); }, })(argumentsNode);   // Attach any default arguments found to the function node directly, // proceed with the rest of the parsers return next([ { ...node, meta: { ...node.meta, DEFAULT_ARGUMENTS: defaultArguments }, }, context, ]); }, // There isn't a need to parse out the Assignment expressions as they are // not actually compiled/generated into the final binary // [Syntax.Assignment]: next => (args, transform) => { // const [node, context] = args; // // Not inside arguments // const currentScope = current(context.scopes);   // // Arguments have not been set for scope yet and the current scope is // // not global // if (currentScope.arguments == null && context.scopes.length > 1) { // return next(args); // }   // // Assignment has higher precedence than ":" Pair expressions so the // // children of this node will be [Pair(id:type), Constant(value)] // // remove the constant return the pair. // // // // A helpful visual of a valid default argument syntax: // // // // function fn(x : i32, y : i32, z : i32 = 0) { ... } // const [pair] = node.params;   // // Short circuit the parsers since it does not make sense to process // // assignment anymore. Instead parse the Pair, which is the argument. // return transform([pair, context]); // }, [Syntax.FunctionCall]: next => args => { const [call, context] = args; const { functions } = context; const [id, ...fnArgs] = call.params;   const target = functions[id.value];   // Most likely a built-in function if (!target) { return next(args); }   const expectedArguments = target.meta.FUNCTION_METADATA.argumentsCount; const count = fnArgs.length; const difference = expectedArguments - count; if (difference > 0) { return next([ { ...call, params: [ ...call.params, ...target.meta.DEFAULT_ARGUMENTS.slice(difference - 1), ], }, context, ]); }   return next(args); }, }; }, }; }  </pre></td></tr> </table></pre> <div class='push'></div> </div> <div class='footer quiet pad2 space-top1 center small'> Code coverage generated by <a href="https://istanbul.js.org/" target="_blank">istanbul</a> at Sun Dec 23 2018 17:46:36 GMT+0000 (UTC) </div> </div> <script src="../../prettify.js"></script> <script> window.onload = function () { if (typeof prettyPrint === 'function') { prettyPrint(); } }; </script> <script src="../../sorter.js"></script> </body> </html>