Move environment delimiter handling to functions/environment.js. (#1329)

src/functions.js

@@ -1,6 +1,5 @@
 // @flow
 /** Include this to ensure that all functions are defined. */
-import ParseError from "./ParseError";
 import {
     default as _defineFunction,
     ordargument,
@@ -122,24 +121,7 @@ defineFunction("xArrow", [
 import "./functions/cr";
 
 // Environment delimiters
-defineFunction("environment", ["\\begin", "\\end"], {
-    numArgs: 1,
-    argTypes: ["text"],
-}, function(context, args) {
-    const nameGroup = args[0];
-    if (nameGroup.type !== "ordgroup") {
-        throw new ParseError("Invalid environment name", nameGroup);
-    }
-    let name = "";
-    for (let i = 0; i < nameGroup.value.length; ++i) {
-        name += nameGroup.value[i].value;
-    }
-    return {
-        type: "environment",
-        name: name,
-        nameGroup: nameGroup,
-    };
-});
+import "./functions/environment";
 
 // Box manipulation
 defineFunction("raisebox", ["\\raisebox"], {

src/functions/environment.js

@@ -0,0 +1,29 @@
+// @flow
+import defineFunction from "../defineFunction";
+import ParseError from "../ParseError";
+
+// Environment delimiters. HTML/MathML rendering is defined in the corresponding
+// defineEnvironment definitions.
+defineFunction({
+    type: "environment",
+    names: ["\\begin", "\\end"],
+    props: {
+        numArgs: 1,
+        argTypes: ["text"],
+    },
+    handler(context, args) {
+        const nameGroup = args[0];
+        if (nameGroup.type !== "ordgroup") {
+            throw new ParseError("Invalid environment name", nameGroup);
+        }
+        let name = "";
+        for (let i = 0; i < nameGroup.value.length; ++i) {
+            name += nameGroup.value[i].value;
+        }
+        return {
+            type: "environment",
+            name: name,
+            nameGroup: nameGroup,
+        };
+    },
+});