Preliminary clojure support (#375)

* Preliminary clojure support

* Cleanup

* Support clojure key, value, and item

* Add tests for multiple cursors

* Handle case where selection inside comment

* Add some basic argument support

* More work on clojure

* A bit of cleanup

* Support if statements

Author: pokey

src/languages/clojure.ts

@@ -0,0 +1,192 @@
+import {
+  cascadingMatcher,
+  chainedMatcher,
+  createPatternMatchers,
+  matcher,
+  patternMatcher,
+} from "../util/nodeMatchers";
+import {
+  ScopeType,
+  NodeMatcherAlternative,
+  NodeFinder,
+} from "../typings/Types";
+import { SyntaxNode } from "web-tree-sitter";
+import { delimitedSelector } from "../util/nodeSelectors";
+import { flow, identity } from "lodash";
+import { getChildNodesForFieldName } from "../util/treeSitterUtils";
+import { patternFinder } from "../util/nodeFinders";
+
+/**
+ * Picks a node by rounding down and using the given parity. This function is
+ * useful for picking the picking eg the key in a sequence of key-value pairs
+ * @param parentFinder The finder to use to determine whether the parent is a
+ * match
+ * @param parity The parity that we're looking for
+ * @returns A node finder
+ */
+function parityNodeFinder(parentFinder: NodeFinder, parity: 0 | 1) {
+  return indexNodeFinder(
+    parentFinder,
+    (nodeIndex: number) => Math.floor(nodeIndex / 2) * 2 + parity
+  );
+}
+
+function mapParityNodeFinder(parity: 0 | 1) {
+  return parityNodeFinder(patternFinder("map_lit"), parity);
+}
+
+/**
+ * Creates a node finder which will apply a transformation to the index of a
+ * value node and return the node at the given index of the nodes parent
+ * @param parentFinder A finder which will be applied to the parent to determine
+ * whether it is a match
+ * @param indexTransform A function that will be applied to the index of the
+ * value node. The node at the given index will be used instead of the node
+ * itself
+ * @returns A node finder based on the given description
+ */
+function indexNodeFinder(
+  parentFinder: NodeFinder,
+  indexTransform: (index: number) => number
+) {
+  return (node: SyntaxNode) => {
+    const parent = node.parent;
+
+    if (parent == null || parentFinder(parent) == null) {
+      return null;
+    }
+
+    const valueNodes = getValueNodes(parent);
+
+    const nodeIndex = valueNodes.findIndex(({ id }) => id === node.id);
+
+    if (nodeIndex === -1) {
+      // TODO: In the future we might conceivably try to handle saying "take
+      // item" when the selection is inside a comment between the key and value
+      return null;
+    }
+
+    const desiredIndex = indexTransform(nodeIndex);
+
+    if (desiredIndex === -1) {
+      return null;
+    }
+
+    return valueNodes[desiredIndex];
+  };
+}
+
+function itemFinder() {
+  return indexNodeFinder(
+    (node) => node,
+    (nodeIndex: number) => nodeIndex
+  );
+}
+
+/**
+ * Return the "value" node children of a given node. These are the items in a list
+ * @param node The node whose children to get
+ * @returns A list of the value node children of the given node
+ */
+const getValueNodes = (node: SyntaxNode) =>
+  getChildNodesForFieldName(node, "value");
+
+// A function call is a list literal which is not quoted
+const functionCallPattern = "~quoting_lit.list_lit!";
+const functionCallFinder = patternFinder(functionCallPattern);
+
+/**
+ * Matches a function call if the name of the function is one of the given names
+ * @param names The acceptable function names
+ * @returns The function call node if the name matches otherwise null
+ */
+function functionNameBasedFinder(...names: string[]) {
+  return (node: SyntaxNode) => {
+    const functionCallNode = functionCallFinder(node);
+    if (functionCallNode == null) {
+      return null;
+    }
+
+    const functionNode = getValueNodes(functionCallNode)[0];
+
+    return names.includes(functionNode?.text) ? functionCallNode : null;
+  };
+}
+
+function functionNameBasedMatcher(...names: string[]) {
+  return matcher(functionNameBasedFinder(...names));
+}
+
+const functionFinder = functionNameBasedFinder("defn", "defmacro");
+
+const functionNameMatcher = chainedMatcher([
+  functionFinder,
+  (functionNode) => getValueNodes(functionNode)[1],
+]);
+
+const ifStatementFinder = functionNameBasedFinder(
+  "if",
+  "if-let",
+  "when",
+  "when-let"
+);
+
+const ifStatementMatcher = matcher(ifStatementFinder);
+
+const nodeMatchers: Partial<Record<ScopeType, NodeMatcherAlternative>> = {
+  comment: "comment",
+  map: "map_lit",
+
+  collectionKey: matcher(mapParityNodeFinder(0)),
+  collectionItem: cascadingMatcher(
+    // Treat each key value pair as a single item if we're in a map
+    matcher(
+      mapParityNodeFinder(0),
+      delimitedSelector(
+        (node) => node.type === "{" || node.type === "}",
+        ", ",
+        identity,
+        mapParityNodeFinder(1) as (node: SyntaxNode) => SyntaxNode
+      )
+    ),
+
+    // Otherwise just treat every item within a list as an item
+    matcher(itemFinder())
+  ),
+  value: matcher(mapParityNodeFinder(1)),
+
+  // TODO: Handle formal parameters
+  argumentOrParameter: matcher(
+    indexNodeFinder(patternFinder(functionCallPattern), (nodeIndex: number) =>
+      nodeIndex !== 0 ? nodeIndex : -1
+    )
+  ),
+
+  // A list is either a vector literal or a quoted list literal
+  list: ["vec_lit", "quoting_lit.list_lit"],
+
+  string: "str_lit",
+
+  functionCall: functionCallPattern,
+
+  namedFunction: matcher(functionFinder),
+
+  functionName: functionNameMatcher,
+
+  // TODO: Handle `let` declarations, defs, etc
+  name: functionNameMatcher,
+
+  anonymousFunction: cascadingMatcher(
+    functionNameBasedMatcher("fn"),
+    patternMatcher("anon_fn_lit")
+  ),
+
+  ifStatement: ifStatementMatcher,
+
+  condition: chainedMatcher([
+    ifStatementFinder,
+    (node) => getValueNodes(node)[1],
+  ]),
+};
+
+export default createPatternMatchers(nodeMatchers);

src/languages/constants.ts

@@ -1,5 +1,6 @@
 export const supportedLanguageIds = [
   "c",
+  "clojure",
   "cpp",
   "csharp",
   "java",

src/languages/csharp.ts

@@ -1,7 +1,7 @@
 import { SyntaxNode } from "web-tree-sitter";
 import {
   cascadingMatcher,
-  composedMatcher,
+  chainedMatcher,
   createPatternMatchers,
   matcher,
   trailingMatcher,
@@ -162,26 +162,26 @@ const makeDelimitedSelector = (leftType: string, rightType: string) =>
 
 const getMapMatchers = {
   map: cascadingMatcher(
-    composedMatcher([
+    chainedMatcher([
       typedNodeFinder(...OBJECT_TYPES_WITH_INITIALIZERS_AS_CHILDREN),
       getChildInitializerNode,
     ]),
-    composedMatcher([
+    chainedMatcher([
       typedNodeFinder("object_creation_expression"),
       getInitializerNode,
     ])
   ),
-  collectionKey: composedMatcher([
+  collectionKey: chainedMatcher([
     typedNodeFinder("assignment_expression"),
     (node: SyntaxNode) => node.childForFieldName("left"),
   ]),
   value: matcher((node: SyntaxNode) => node.childForFieldName("right")),
   list: cascadingMatcher(
-    composedMatcher([
+    chainedMatcher([
       typedNodeFinder(...LIST_TYPES_WITH_INITIALIZERS_AS_CHILDREN),
       getChildInitializerNode,
     ]),
-    composedMatcher([
+    chainedMatcher([
       typedNodeFinder("object_creation_expression"),
       (node: SyntaxNode) => node.childForFieldName("initializer"),
     ])

src/languages/getNodeMatcher.ts

@@ -8,10 +8,11 @@ import {
   SelectionWithEditor,
 } from "../typings/Types";
 import cpp from "./cpp";
+import clojure from "./clojure";
 import csharp from "./csharp";
 import { patternMatchers as json } from "./json";
 import { patternMatchers as typescript } from "./typescript";
-import { patternMatchers as java } from "./java";
+import java from "./java";
 import python from "./python";
 import { UnsupportedLanguageError } from "../errors";
 import { SupportedLanguageId } from "./constants";
@@ -45,7 +46,8 @@ const languageMatchers: Record<
   Record<ScopeType, NodeMatcher>
 > = {
   c: cpp,
-  cpp: cpp,
+  clojure,
+  cpp,
   csharp: csharp,
   java,
   javascript: typescript,

src/languages/getTextFragmentExtractor.ts

@@ -1,7 +1,6 @@
 import { SyntaxNode } from "web-tree-sitter";
 import { SelectionWithEditor } from "../typings/Types";
 import { stringTextFragmentExtractor as jsonStringTextFragmentExtractor } from "./json";
-import { stringTextFragmentExtractor as javaStringTextFragmentExtractor } from "./java";
 import { stringTextFragmentExtractor as typescriptStringTextFragmentExtractor } from "./typescript";
 import { UnsupportedLanguageError } from "../errors";
 import { Range } from "vscode";
@@ -67,6 +66,33 @@ function constructDefaultStringTextFragmentExtractor(
   };
 }
 
+/**
+ * Extracts string text fragments in languages that don't have quotation mark
+ * tokens as children of string tokens, but instead include them in the text of
+ * the string.
+ *
+ * This is a hack. Rather than letting the parse tree handle the quotation marks
+ * in java, we instead just let the textual surround handle them by letting it
+ * see the quotation marks. In other languages we prefer to let the parser
+ * handle the quotation marks in case they are more than one character long.
+ * @param node The node which might be a string node
+ * @param selection The selection from which to expand
+ * @returns The range of the string text or null if the node is not a string
+ */
+function constructHackedStringTextFragmentExtractor(
+  languageId: SupportedLanguageId
+) {
+  const stringNodeMatcher = getNodeMatcher(languageId, "string", false);
+
+  return (node: SyntaxNode, selection: SelectionWithEditor) => {
+    if (stringNodeMatcher(selection, node) != null) {
+      return getNodeRange(node);
+    }
+
+    return null;
+  };
+}
+
 /**
  * Returns a function which can be used to extract the range of a text fragment
  * from within a parsed language. This function should only return a nominal
@@ -94,11 +120,15 @@ const textFragmentExtractors: Record<
   TextFragmentExtractor
 > = {
   c: constructDefaultTextFragmentExtractor("c"),
+  clojure: constructDefaultTextFragmentExtractor(
+    "clojure",
+    constructHackedStringTextFragmentExtractor("clojure")
+  ),
   cpp: constructDefaultTextFragmentExtractor("cpp"),
   csharp: constructDefaultTextFragmentExtractor("csharp"),
   java: constructDefaultTextFragmentExtractor(
     "java",
-    javaStringTextFragmentExtractor
+    constructHackedStringTextFragmentExtractor("java")
   ),
   javascript: constructDefaultTextFragmentExtractor(
     "javascript",

src/languages/java.ts

@@ -5,13 +5,7 @@ import {
   conditionMatcher,
   trailingMatcher,
 } from "../util/nodeMatchers";
-import {
-  NodeMatcherAlternative,
-  ScopeType,
-  SelectionWithEditor,
-} from "../typings/Types";
-import { getNodeRange } from "../util/nodeSelectors";
-import { SyntaxNode } from "web-tree-sitter";
+import { NodeMatcherAlternative, ScopeType } from "../typings/Types";
 
 // Generated by the following command:
 // > curl https://raw.githubusercontent.com/tree-sitter/tree-sitter-java/master/src/node-types.json | jq '[.[] | select(.type == "statement" or .type == "declaration") | .subtypes[].type]'
@@ -78,28 +72,4 @@ const nodeMatchers: Partial<Record<ScopeType, NodeMatcherAlternative>> = {
   argumentOrParameter: argumentMatcher("formal_parameters", "argument_list"),
 };
 
-export const patternMatchers = createPatternMatchers(nodeMatchers);
-
-/**
- * Extracts string text fragments in java.
- *
- * This is a hack to deal with the fact that java doesn't have
- * quotation mark tokens as children of the string. Rather than letting
- * the parse tree handle the quotation marks in java, we instead just
- * let the textual surround handle them by letting it see the quotation
- * marks. In other languages we prefer to let the parser handle the
- * quotation marks in case they are more than one character long.
- * @param node The node which might be a string node
- * @param selection The selection from which to expand
- * @returns The range of the string text or null if the node is not a string
- */
-export function stringTextFragmentExtractor(
-  node: SyntaxNode,
-  selection: SelectionWithEditor
-) {
-  if (node.type === "string_literal") {
-    return getNodeRange(node);
-  }
-
-  return null;
-}
+export default createPatternMatchers(nodeMatchers);