1 files changed, 79 insertions, 0 deletions

diff --git a/editors/code/src/scopes_mapper.ts b/editors/code/src/scopes_mapper.ts
new file mode 100644
index 000000000..85c791ff5
--- /dev/null
+++ b/editors/code/src/scopes_mapper.ts
@@ -0,0 +1,79 @@
+import * as vscode from 'vscode';
+import { TextMateRuleSettings } from './scopes';
+
+let mappings = new Map<string, string[]>();
+
+const defaultMapping = new Map<string, string[]>([
+    [
+        'comment',
+        [
+            'comment',
+            'comment.block',
+            'comment.line',
+            'comment.block.documentation'
+        ]
+    ],
+    ['string', ['string']],
+    ['keyword', ['keyword']],
+    ['keyword.control', ['keyword.control', 'keyword', 'keyword.other']],
+    [
+        'keyword.unsafe',
+        ['storage.modifier', 'keyword.other', 'keyword.control', 'keyword']
+    ],
+    ['function', ['entity.name.function']],
+    ['parameter', ['variable.parameter']],
+    ['constant', ['constant', 'variable']],
+    ['type', ['entity.name.type']],
+    ['builtin', ['variable.language', 'support.type', 'support.type']],
+    ['text', ['string', 'string.quoted', 'string.regexp']],
+    ['attribute', ['keyword']],
+    ['literal', ['string', 'string.quoted', 'string.regexp']],
+    ['macro', ['support.other']],
+    ['variable', ['variable']],
+    ['variable.mut', ['variable', 'storage.modifier']],
+    [
+        'field',
+        [
+            'variable.object.property',
+            'meta.field.declaration',
+            'meta.definition.property',
+            'variable.other'
+        ]
+    ],
+    ['module', ['entity.name.section', 'entity.other']]
+]);
+
+// Temporary exported for debugging for now.
+export function find(scope: string): string[] {
+    return mappings.get(scope) || [];
+}
+
+export function toRule(
+    scope: string,
+    intoRule: (scope: string) => TextMateRuleSettings | undefined
+): TextMateRuleSettings | undefined {
+    return find(scope)
+        .map(intoRule)
+        .filter(rule => rule !== undefined)[0];
+}
+
+function isString(value: any): value is string {
+    return typeof value === 'string';
+}
+
+function isArrayOfString(value: any): value is string[] {
+    return Array.isArray(value) && value.every(item => isString(item));
+}
+
+export function load() {
+    const rawConfig: { [key: string]: any } =
+        vscode.workspace
+            .getConfiguration('rust-analyzer')
+            .get('scopeMappings') || {};
+
+    mappings = Object.entries(rawConfig)
+        .filter(([_, value]) => isString(value) || isArrayOfString(value))
+        .reduce((list, [key, value]: [string, string | string[]]) => {
+            return list.set(key, isString(value) ? [value] : value);
+        }, defaultMapping);
+}