Merge pull request #347 from gagern/splitEnvironments

Split up environments list into calls to defineEnvironment

src/environments.js

@@ -38,32 +38,54 @@ function parseArray(parser, pos, mode, result) {
 }
 
 /*
- * An environment definition is very similar to a function definition.
+ * An environment definition is very similar to a function definition:
- * Each element of the following array may contain
+ * it is declared with a name or a list of names, a set of properties
- *  - names: The names associated with a function. This can be used to
+ * and a handler containing the actual implementation.
- *           share one implementation between several similar environments.
+ *
+ * The properties include:
  *  - numArgs: The number of arguments after the \begin{name} function.
  *  - argTypes: (optional) Just like for a function
  *  - allowedInText: (optional) Whether or not the environment is allowed inside
  *                   text mode (default false) (not enforced yet)
  *  - numOptionalArgs: (optional) Just like for a function
- *  - handler: The function that is called to handle this environment.
+ * A bare number instead of that object indicates the numArgs value.
- *             It will receive the following arguments:
+ *
+ * The handler function will receive the following arguments:
  *  - pos: the current position of the parser.
  *  - mode: the current parsing mode.
  *  - envName: the name of the environment, one of the listed names.
  *  - [args]: the arguments passed to \begin.
  *  - positions: the positions associated with these arguments.
+ * The handler is called with `this` referring to the parser.
+ * It must return a ParseResult.
  */
 
-var environmentDefinitions = [
+function defineEnvironment(names, props, handler) {
+    if (typeof names === "string") {
+        names = [names];
+    }
+    if (typeof props === "number") {
+        props = { numArgs: props };
+    }
+    // Set default values of environments
+    var data = {
+        numArgs: props.numArgs || 0,
+        argTypes: props.argTypes,
+        greediness: 1,
+        allowedInText: !!props.allowedInText,
+        numOptionalArgs: props.numOptionalArgs || 0,
+        handler: handler
+    };
+    for (var i = 0; i < names.length; ++i) {
+        module.exports[names[i]] = data;
+    }
+}
 
 // Arrays are part of LaTeX, defined in lttab.dtx so its documentation
 // is part of the source2e.pdf file of LaTeX2e source documentation.
-    {
+defineEnvironment("array", {
-        names: ["array"],
+    numArgs: 1
-        numArgs: 1,
+}, function(pos, mode, envName, colalign, positions) {
-        handler: function(pos, mode, envName, colalign, positions) {
     var parser = this;
     colalign = colalign.value.map ? colalign.value : [colalign];
     var cols = colalign.map(function(node) {
@@ -90,21 +112,19 @@ var environmentDefinitions = [
     };
     res = parseArray(parser, pos, mode, res);
     return res;
-        }
+});
-    },
 
 // The matrix environments of amsmath builds on the array environment
 // of LaTeX, which is discussed above.
-    {
+defineEnvironment([
-        names: [
     "matrix",
     "pmatrix",
     "bmatrix",
     "Bmatrix",
     "vmatrix",
     "Vmatrix"
-        ],
+], {
-        handler: function(pos, mode, envName) {
+}, function(pos, mode, envName) {
     var delimiters = {
         "matrix": null,
         "pmatrix": ["(", ")"],
@@ -126,15 +146,13 @@ var environmentDefinitions = [
         }, mode);
     }
     return res;
-        }
+});
-    },
 
 // A cases environment (in amsmath.sty) is almost equivalent to
 // \def\arraystretch{1.2}%
 // \left\{\begin{array}{@{}l@{\quad}l@{}} … \end{array}\right.
-    {
+defineEnvironment("cases", {
-        names: ["cases"],
+}, function(pos, mode, envName) {
-        handler: function(pos, mode, envName) {
     var res = {
         type: "array",
         arraystretch: 1.2,
@@ -157,22 +175,4 @@ var environmentDefinitions = [
         right: "."
     }, mode);
     return res;
-        }
+});
-    }
-];
-
-module.exports = (function() {
-    // nested function so we don't leak i and j into the module scope
-    var exports = {};
-    for (var i = 0; i < environmentDefinitions.length; ++i) {
-        var def = environmentDefinitions[i];
-        def.greediness = 1;
-        def.allowedInText = !!def.allowedInText;
-        def.numArgs = def.numArgs || 0;
-        def.numOptionalArgs = def.numOptionalArgs || 0;
-        for (var j = 0; j < def.names.length; ++j) {
-            exports[def.names[j]] = def;
-        }
-    }
-    return exports;
-})();