diff --git a/ast.json b/ast.json
index 4d319a8..ec9f41a 100644
--- a/ast.json
+++ b/ast.json
@@ -11,44 +11,39 @@
     },
     {
         "type": "Group",
-        "value": "{",
-        "tokens": [
-            {
-                "type": "Left Delimiter",
-                "value": "{",
-                "layer": 0
-            }
-        ]
-    },
-    {
-        "type": "Group",
-        "value": "a",
+        "value": "(",
         "tokens": [
             {
                 "type": "Variable",
                 "value": "a",
-                "layer": 2
-            },
-            {
-                "type": "Operator",
-                "value": "++",
-                "layer": 2
+                "layer": 1
             }
         ]
     },
     {
         "type": "Group",
-        "value": "asdf",
+        "value": "{",
         "tokens": [
             {
-                "type": "Variable",
-                "value": "asdf",
-                "layer": 0
+                "type": "Function Call",
+                "value": "return",
+                "layer": 1
             },
             {
-                "type": "Operator",
-                "value": "=",
-                "layer": 0
+                "type": "Group",
+                "value": "(",
+                "tokens": [
+                    {
+                        "type": "Variable",
+                        "value": "a",
+                        "layer": 2
+                    },
+                    {
+                        "type": "Operator",
+                        "value": "++",
+                        "layer": 2
+                    }
+                ]
             }
         ]
     }
diff --git a/classes.js b/classes.js
index e5df2f0..4d59265 100644
--- a/classes.js
+++ b/classes.js
@@ -1,20 +1,21 @@
 // This is the most basic type of token.
 var token = function (type, value) {
-	this.type = type;
-	this.value = value;
+  this.type = type;
+  this.value = value;
 };
 // This is a group of tokens.
-var group = function (type, tokens) {
-    this.type = "Group";
-    this.value = type;
-    this.tokens;
-    if(typeof tokens != "undefined") {
-        this.tokens = tokens;
-    } else {
-        this.tokens = [];
-    }
+var group = function (type, tokens, index) {
+  this.type = "Group";
+  this.value = type;
+  this.index = index;
+  this.tokens;
+  if (typeof tokens != "undefined") {
+    this.tokens = tokens;
+  } else {
+    this.tokens = [];
+  }
 }
 module.exports = {
-	token: token,
-	group: group
-}
+  token: token,
+  group: group
+}
\ No newline at end of file
diff --git a/parser.js b/parser.js
index e163023..50cba2f 100644
--- a/parser.js
+++ b/parser.js
@@ -5,55 +5,130 @@ const group = require("./classes.js").group;
 // parse() takes an array of tokens in, and outputs an
 // Abstract Syntax Tree (a structured array of tokens).
 module.exports = tokens => {
-	// Variables for later.
-	var layer = 0;
-    var delimiterCount = 0;
-    var deepestLayer = 0;
-	// Give each token a layer number based on delimiters.
-	for (var i = 0; i < tokens.length; i++) {
-		if (tokens[i].type == "Left Delimiter") {
-            layer++;
-            if(layer > deepestLayer) {
-                deepestLayer = layer;
-            }
-			delimiterCount++;
-		}
-		tokens[i].layer = layer;
-		if (tokens[i].type == "Right Delimiter") {
-			layer--;
-		}
+  // Variables for later.
+  var layer = 0;
+  var delimiterCount = 0;
+  var deepestLayer = 0;
+  // Give each token a layer number based on delimiters.
+  for (var i = 0; i < tokens.length; i++) {
+    if (tokens[i].type == "Left Delimiter") {
+      layer++;
+      if (layer > deepestLayer) {
+        deepestLayer = layer;
+      }
+      delimiterCount++;
     }
-	// Lower the layer of delimiters.
-	for (var i = 0; i < tokens.length; i++) {
-		if ((tokens[i].type == "Left Delimiter") || (tokens[i].type == "Right Delimiter")) {
-            tokens[i].layer--;
-		}
-	}
-	if (layer > 0) { // Unclosed delimiter.
-	} else if (layer < 0) { // Overclosed delimiter.
-	}
-	// Reset layer for structuring.
-    layer = 0;
-	/* - - - DO NOT TOUCH THIS - - - */
-    for(var i=deepestLayer;i>=0;i--) {
-        var temp = [];
-        var firstIndex;
-        for(var j=0;j<tokens.length;j++) {
-            if(tokens[j].layer == i) {
-                if(temp.length <= 0) {
-                    firstIndex = j;
-                }
-                temp.push(tokens[j]);
-            } else {
-                if(temp.length > 0) {
-                    var g = new group(tokens[firstIndex].value,temp);
-                    tokens.splice(firstIndex-1,temp.length+2,g);
-                    temp = [];
-                }
-            }
+    tokens[i].layer = layer;
+    if (tokens[i].type == "Right Delimiter") {
+      layer--;
+    }
+  }
+  // Lower the layer of delimiters.
+  for (var i = 0; i < tokens.length; i++) {
+    if ((tokens[i].type == "Left Delimiter") || (tokens[i].type == "Right Delimiter")) {
+      tokens[i].layer--;
+    }
+  }
+  if (layer > 0) { // Unclosed delimiter.
+  } else if (layer < 0) { // Overclosed delimiter.
+  }
+  // Give each token an index.
+  for (let i = 0; i < tokens.length; i++) {
+    tokens[i].index = i;
+  }
+  // Structure the layers.
+  // Count the rising edges of the layers to determine how many groups should exist.
+  let structure = function () {
+    let layer = 0;
+    let risingFalling = []; // Create an array to store indices of rising/falling edges.
+    for (let i = 0; i < tokens.length; i++) {
+      // Add a rising and a falling tag to each token.
+      tokens[i].rising = false;
+      tokens[i].falling = false;
+      if (tokens[i].layer > layer) { // If the token moves up a layer.
+        // Create a new rising index in risingFalling.
+        risingFalling.push({
+          type: 'rising',
+          index: i
+        });
+        tokens[i].rising = true; // Note that the token is a rising edge.
+        layer++;
+      } else if (tokens[i].layer < layer) {
+        // Create a new falling index in risingFalling.
+        risingFalling.push({
+          type: 'falling',
+          index: i
+        });
+        tokens[i].falling = true; // Note that the token is a falling edge.
+        layer--;
+      }
+    }
+    // Loop through the list of rising/falling edges.
+    for (let i = 0; i < risingFalling.length; i++) {
+      if (i != risingFalling.length - 1) { // If not the last edge.
+        let item = risingFalling[i];
+        let nextItem = risingFalling[i + 1];
+        // If a falling edge follows a rising edge, classifiy it as a group.
+        if ((item.type == 'rising') && (nextItem.type == 'falling')) {
+          // Get the group together as one item.
+          let selectedItems = tokens.slice(item.index, nextItem.index);
+          tokens.splice(item.index, selectedItems.length, new group(tokens[item.index - 1].value, selectedItems, item.index));
         }
+      }
     }
-	/* - - - OK YOU CAN TOUCH AGAIN - - - */
-	// Return the structured tokens.
-	return tokens;
-};
+    risingFalling = []; // Reset the list of edges.
+    // Count the edges again.
+    for (let i = 0; i < tokens.length; i++) {
+      if (tokens[i].layer > layer) {
+        risingFalling.push({
+          type: 'rising',
+          index: i
+        });
+        layer++;
+      } else if (tokens[i].layer < layer) {
+        risingFalling.push({
+          type: 'falling',
+          index: i
+        });
+        layer--;
+      }
+    }
+    // If there are still edges, run again.
+    if (risingFalling.length) {
+      structure();
+    }
+  };
+  // Start the recursion.
+  structure();
+  let trimDelimiters = function (thing) {
+    // Loop through the tokens of thing.
+    for (let i = 0; i < thing.length; i++) {
+      // Delete unnecessary keys.
+      if (typeof thing[i].rising != 'undefined') {
+        delete thing[i].rising;
+      }
+      if (typeof thing[i].falling != 'undefined') {
+        delete thing[i].falling;
+      }
+      if (typeof thing[i].index != 'undefined') {
+        delete thing[i].index;
+      }
+      if (typeof thing[i].index != 'undefined') {
+        delete thing[i].index;
+      }
+      // Remove delimiters.
+      if ((thing[i].type == 'Left Delimiter') || (thing[i].type == 'Right Delimiter')) {
+        thing.splice(i, 1);
+        i--;
+      }
+      // If a token is a group, look at the group's tokens.
+      if (thing[i].type == 'Group') {
+        trimDelimiters(thing[i].tokens);
+      }
+    }
+  };
+  // Start the recursion.
+  trimDelimiters(tokens);
+  // Return the structured tokens.
+  return tokens;
+};
\ No newline at end of file
diff --git a/pivot.js b/pivot.js
index e9d92cc..2b75014 100644
--- a/pivot.js
+++ b/pivot.js
@@ -10,4 +10,4 @@ var ast = parse(tokenize(code));
 
 // Write the AST to ast.json.
 var fs = require("fs");
-fs.writeFileSync("ast.json", JSON.stringify(ast, null, 4));
+fs.writeFileSync("ast.json", JSON.stringify(ast, null, 4));
\ No newline at end of file
diff --git a/tokenizer.js b/tokenizer.js
index b1ba7f9..f8dab7d 100644
--- a/tokenizer.js
+++ b/tokenizer.js
@@ -3,168 +3,168 @@ const token = require("./classes.js").token;
 
 // Create the tokenizer function.
 // tokenize() takes Pivot code in, and outputs an array of tokens.
-module.exports =  exp => {
-	// Check functions for different token types.
-	var isDigit = char => {
-		return /\d/.test(char);
-	};
-	var isLetter = char => {
-		return /[a-z]/i.test(char);
-	};
-	var isOperator = char => {
-		return /\+|-|\*|\/|\^|=/.test(char);
-	};
-	var isLeftDelimiter = char => {
-		return (/\(|\[|\{|"|'|`/.test(char));
-	};
-	var isRightDelimiter = char => {
-		return (/\)|\]|\}/.test(char));
-	};
-	var isComma = char => {
-		return (char === ",");
-	};
-	var isPeriod = char => {
-		return (char === ".");
-	};
-	var result = []; // The final array of tokens.
-	var nb = []; // Number buffer. Allows for multiple digits to be one number.
-	var lb = []; // Letter buffer. Allows for multiple letters to be one variable / function.
-	var ob = []; // Operator buffer. Allows for multi-character operators. E.g. ++ or ==.
-	var sb = []; // String buffer. Allows for multi-character strings.
-	var inString = false; // Keep track of whether in string or not.
-	var stringType; // Keep track of what type of string. E.g. "" or ''.
-	exp = exp.split(""); // Split the expression into an array of characters.
-	/* - - - DO NOT TOUCH THIS - - - */
-	for (var i = 0; i < exp.length; i++) { // Loop through all of the characters.
-		var char = exp[i]; // Create a quick reference to the current char.
-		if (i >= 1) {
-			if (exp[i - 1] == "\\") {
-				exp.splice(i - 1, 2, `\\${char}`);
-				i--;
-				continue;
-			}
-			if (exp[i - 1] == "$" && char == "{") {
-				exp.splice(i - 1, 2, `\${`);
-				i--;
-				continue;
-			}
-		}
-	}
-	/* - - - OK YOU CAN TOUCH AGAIN - - - */
-	// Nevermind, just don't mess with any of this file.
-	for (var i = 0; i < exp.length; i++) {
-		var char = exp[i];
-		if (inString) {
-			if (char == `'` || char == `"` || char == "`") {
-				var exitString = () => {
-					inString = false;
-					if (sb.length == 0) {
-						result.push(new token("String", null));
-					} else {
-						var string = sb.join("");
-						result.push(new token("String", string));
-					}
-					sb = [];
-				};
-				if (char == `'` && stringType == "single") {
-					exitString();
-				} else if (char == `"` && stringType == "double") {
-					exitString();
-				} else if (char == "`" && stringType == "backtick") {
-					exitString();
-				} else {
-					if (char == `'`) {
-						sb.push(`\'`);
-					}
-					if (char == `"`) {
-						sb.push(`\"`);
-					}
-					if (char == "`") {
-						sb.push("\`");
-					}
-				}
-			} else {
-				sb.push(char);
-			}
-		} else {
-			if (isDigit(char)) {
-				result.push(new token("Operator", ob.join("")));
-				ob = [];
-				nb.push(char);
-			} else if (isLetter(char)) {
-				result.push(new token("Operator", ob.join("")));
-				ob = [];
-				lb.push(char);
-			} else if (isOperator(char)) {
-				result.push(new token("Number", nb.join("")));
-				nb = [];
-				result.push(new token("Variable", lb.join("")));
-				lb = [];
-				ob.push(char);
-			} else if (isLeftDelimiter(char)) {
-				result.push(new token("Operator", ob.join("")));
-				ob = [];
-				result.push(new token("Function Call", lb.join("")));
-				lb = [];
-				if (char == `'` || char == `"` || char == "`") {
-					inString = true;
-					if (char == `'`) {
-						stringType = "single";
-					} else if (char == `"`) {
-						stringType = "double";
-					} else if (char == "`") {
-						stringType = "backtick";
-					}
-				} else {
-					result.push(new token("Left Delimiter", char));
-				}
-			} else if (isRightDelimiter(char)) {
-				result.push(new token("Operator", ob.join("")));
-				ob = [];
-				result.push(new token("Number", nb.join("")));
-				nb = [];
-				result.push(new token("Variable", lb.join("")));
-				lb = [];
-				result.push(new token("Right Delimiter", char));
-			} else if (isComma(char)) {
-				result.push(new token("Operator", ob.join("")));
-				ob = [];
-				result.push(new token("Number", nb.join("")));
-				nb = [];
-				result.push(new token("Variable", lb.join("")));
-				lb = [];
-				result.push(new token("Comma", char));
-			} else if (isPeriod(char)) {
-				result.push(new token("Operator", ob.join("")));
-				ob = [];
-				nb.push(char);
-			}
-		}
-	}
-	result.push(new token("Operator", ob.join("")));
-	ob = [];
-	result.push(new token("Number", nb.join("")));
-	nb = [];
-	lb.forEach(item => {
-		result.push(new token("Variable", item));
-	});
-	lb = [];
-	for (var i = 0; i < 3; i++) {
-		result.forEach((item, index) => {
-			if (item.value == "") {
-				result.splice(index, 1);
-			}
-		});
-	}
-	result.forEach((item, index) => {
-		if (item.value == "-" && index != 0) {
-			if (result[index - 1].type != "Variable" && result[index - 1].type != "Number") {
-				if (result[index + 1].type == "Number") {
-					result[index + 1].value = "-" + result[index + 1].value;
-					result.splice(index, 1);
-				}
-			}
-		}
-	});
-	return result;
-};
+module.exports = exp => {
+  // Check functions for different token types.
+  var isDigit = char => {
+    return /\d/.test(char);
+  };
+  var isLetter = char => {
+    return /[a-z]/i.test(char);
+  };
+  var isOperator = char => {
+    return /\+|-|\*|\/|\^|=/.test(char);
+  };
+  var isLeftDelimiter = char => {
+    return (/\(|\[|\{|"|'|`/.test(char));
+  };
+  var isRightDelimiter = char => {
+    return (/\)|\]|\}/.test(char));
+  };
+  var isComma = char => {
+    return (char === ",");
+  };
+  var isPeriod = char => {
+    return (char === ".");
+  };
+  var result = []; // The final array of tokens.
+  var nb = []; // Number buffer. Allows for multiple digits to be one number.
+  var lb = []; // Letter buffer. Allows for multiple letters to be one variable / function.
+  var ob = []; // Operator buffer. Allows for multi-character operators. E.g. ++ or ==.
+  var sb = []; // String buffer. Allows for multi-character strings.
+  var inString = false; // Keep track of whether in string or not.
+  var stringType; // Keep track of what type of string. E.g. "" or ''.
+  exp = exp.split(""); // Split the expression into an array of characters.
+  /* - - - DO NOT TOUCH THIS - - - */
+  for (var i = 0; i < exp.length; i++) { // Loop through all of the characters.
+    var char = exp[i]; // Create a quick reference to the current char.
+    if (i >= 1) {
+      if (exp[i - 1] == "\\") {
+        exp.splice(i - 1, 2, `\\${char}`);
+        i--;
+        continue;
+      }
+      if (exp[i - 1] == "$" && char == "{") {
+        exp.splice(i - 1, 2, `\${`);
+        i--;
+        continue;
+      }
+    }
+  }
+  /* - - - OK YOU CAN TOUCH AGAIN - - - */
+  // Nevermind, just don't mess with any of this file.
+  for (var i = 0; i < exp.length; i++) {
+    var char = exp[i];
+    if (inString) {
+      if (char == `'` || char == `"` || char == "`") {
+        var exitString = () => {
+          inString = false;
+          if (sb.length == 0) {
+            result.push(new token("String", null));
+          } else {
+            var string = sb.join("");
+            result.push(new token("String", string));
+          }
+          sb = [];
+        };
+        if (char == `'` && stringType == "single") {
+          exitString();
+        } else if (char == `"` && stringType == "double") {
+          exitString();
+        } else if (char == "`" && stringType == "backtick") {
+          exitString();
+        } else {
+          if (char == `'`) {
+            sb.push(`\'`);
+          }
+          if (char == `"`) {
+            sb.push(`\"`);
+          }
+          if (char == "`") {
+            sb.push("\`");
+          }
+        }
+      } else {
+        sb.push(char);
+      }
+    } else {
+      if (isDigit(char)) {
+        result.push(new token("Operator", ob.join("")));
+        ob = [];
+        nb.push(char);
+      } else if (isLetter(char)) {
+        result.push(new token("Operator", ob.join("")));
+        ob = [];
+        lb.push(char);
+      } else if (isOperator(char)) {
+        result.push(new token("Number", nb.join("")));
+        nb = [];
+        result.push(new token("Variable", lb.join("")));
+        lb = [];
+        ob.push(char);
+      } else if (isLeftDelimiter(char)) {
+        result.push(new token("Operator", ob.join("")));
+        ob = [];
+        result.push(new token("Function Call", lb.join("")));
+        lb = [];
+        if (char == `'` || char == `"` || char == "`") {
+          inString = true;
+          if (char == `'`) {
+            stringType = "single";
+          } else if (char == `"`) {
+            stringType = "double";
+          } else if (char == "`") {
+            stringType = "backtick";
+          }
+        } else {
+          result.push(new token("Left Delimiter", char));
+        }
+      } else if (isRightDelimiter(char)) {
+        result.push(new token("Operator", ob.join("")));
+        ob = [];
+        result.push(new token("Number", nb.join("")));
+        nb = [];
+        result.push(new token("Variable", lb.join("")));
+        lb = [];
+        result.push(new token("Right Delimiter", char));
+      } else if (isComma(char)) {
+        result.push(new token("Operator", ob.join("")));
+        ob = [];
+        result.push(new token("Number", nb.join("")));
+        nb = [];
+        result.push(new token("Variable", lb.join("")));
+        lb = [];
+        result.push(new token("Comma", char));
+      } else if (isPeriod(char)) {
+        result.push(new token("Operator", ob.join("")));
+        ob = [];
+        nb.push(char);
+      }
+    }
+  }
+  result.push(new token("Operator", ob.join("")));
+  ob = [];
+  result.push(new token("Number", nb.join("")));
+  nb = [];
+  lb.forEach(item => {
+    result.push(new token("Variable", item));
+  });
+  lb = [];
+  for (var i = 0; i < 3; i++) {
+    result.forEach((item, index) => {
+      if (item.value == "") {
+        result.splice(index, 1);
+      }
+    });
+  }
+  result.forEach((item, index) => {
+    if (item.value == "-" && index != 0) {
+      if (result[index - 1].type != "Variable" && result[index - 1].type != "Number") {
+        if (result[index + 1].type == "Number") {
+          result[index + 1].value = "-" + result[index + 1].value;
+          result.splice(index, 1);
+        }
+      }
+    }
+  });
+  return result;
+};
\ No newline at end of file