Dedupe some utility code

sandersn · sandersn · commit 2eec7f3565e2 · 2017-06-30T09:23:00.000-07:00
1. convertToArray is a duplicate of arrayFrom
2. inferFromParameterTypes delegates immediately to inferFromTypes
3. One usage of arrayFrom instantiated a whole iterator only to take the
first element, which is the same as calling `next`.
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -1930,7 +1930,7 @@ namespace ts {
         }
 
         function createTypeofType() {
-            return getUnionType(convertToArray(typeofEQFacts.keys(), getLiteralType));
+            return getUnionType(arrayFrom(typeofEQFacts.keys(), getLiteralType));
         }
 
         // A reserved member name starts with two underscores, but the third character cannot be an underscore
@@ -10531,12 +10531,8 @@ namespace ts {
                 }
             }
 
-            function inferFromParameterTypes(source: Type, target: Type) {
-                return inferFromTypes(source, target);
-            }
-
             function inferFromSignature(source: Signature, target: Signature) {
-                forEachMatchingParameterType(source, target, inferFromParameterTypes);
+                forEachMatchingParameterType(source, target, inferFromTypes);
 
                 if (source.typePredicate && target.typePredicate && source.typePredicate.kind === target.typePredicate.kind) {
                     inferFromTypes(source.typePredicate.type, target.typePredicate.type);
diff --git a/src/compiler/commandLineParser.ts b/src/compiler/commandLineParser.ts
@@ -1290,7 +1290,7 @@ namespace ts {
                 case "object":
                     return {};
                 default:
-                    return arrayFrom((<CommandLineOptionOfCustomType>option).type.keys())[0];
+                    return (option as CommandLineOptionOfCustomType).type.keys().next().value;
             }
         }
 
diff --git a/src/compiler/core.ts b/src/compiler/core.ts
@@ -996,14 +996,6 @@ namespace ts {
         return result;
     }
 
-    export function convertToArray<T, U>(iterator: Iterator<T>, f: (value: T) => U) {
-        const result: U[] = [];
-        for (let { value, done } = iterator.next(); !done; { value, done } = iterator.next()) {
-            result.push(f(value));
-        }
-        return result;
-    }
-
     /**
      * Calls `callback` for each entry in the map, returning the first truthy result.
      * Use `map.forEach` instead for normal iteration.
@@ -2527,4 +2519,4 @@ namespace ts {
     export function isCheckJsEnabledForFile(sourceFile: SourceFile, compilerOptions: CompilerOptions) {
         return sourceFile.checkJsDirective ? sourceFile.checkJsDirective.enabled : compilerOptions.checkJs;
     }
-}
+}

Original file line number	Diff line number	Diff line change
`@@ -1930,7 +1930,7 @@ namespace ts {`
`1930`	`1930`	`}`
`1931`	`1931`
`1932`	`1932`	`function createTypeofType() {`
`1933`		`- return getUnionType(convertToArray(typeofEQFacts.keys(), getLiteralType));`
	`1933`	`+ return getUnionType(arrayFrom(typeofEQFacts.keys(), getLiteralType));`
`1934`	`1934`	`}`
`1935`	`1935`
`1936`	`1936`	`// A reserved member name starts with two underscores, but the third character cannot be an underscore`
`@@ -10531,12 +10531,8 @@ namespace ts {`
`10531`	`10531`	`}`
`10532`	`10532`	`}`
`10533`	`10533`
`10534`		`- function inferFromParameterTypes(source: Type, target: Type) {`
`10535`		`- return inferFromTypes(source, target);`
`10536`		`- }`
`10537`		`-`
`10538`	`10534`	`function inferFromSignature(source: Signature, target: Signature) {`
`10539`		`- forEachMatchingParameterType(source, target, inferFromParameterTypes);`
	`10535`	`+ forEachMatchingParameterType(source, target, inferFromTypes);`
`10540`	`10536`
`10541`	`10537`	`if (source.typePredicate && target.typePredicate && source.typePredicate.kind === target.typePredicate.kind) {`
`10542`	`10538`	`inferFromTypes(source.typePredicate.type, target.typePredicate.type);`
Original file line number	Diff line number	Diff line change
`@@ -1290,7 +1290,7 @@ namespace ts {`
`1290`	`1290`	`case "object":`
`1291`	`1291`	`return {};`
`1292`	`1292`	`default:`
`1293`		`- return arrayFrom((<CommandLineOptionOfCustomType>option).type.keys())[0];`
	`1293`	`+ return (option as CommandLineOptionOfCustomType).type.keys().next().value;`
`1294`	`1294`	`}`
`1295`	`1295`	`}`
`1296`	`1296`