diff --git a/lib/parse.js b/lib/parse.js
index 805d869..8eb83da 100644
--- a/lib/parse.js
+++ b/lib/parse.js
@@ -1,220 +1,168 @@
+/**
+ * Methods in this file walk the AST and call the instrumenter
+ * functions where appropriate, which determine where to inject events.
+ * (Listed in alphabetical order)
+ */
+
 const parse = {};
 const instrumenter = require('./instrumenter');
 
-// All the functions in this file do is walk the AST and call the instrumenter
-// functions where appropriate, which determine where to inject events.
-
-// Assign a dummy function to everything we might see in the AST
-['AssemblyAssignment',
-  'AssemblyItem',
-  'AssemblyLocalBinding',
-  'AssignmentExpression',
-  'BinaryExpression',
-  'BlockStatement',
-  'BreakStatement',
-  'CallExpression',
-  'ConditionalExpression',
-  'ContinueStatement',
-  'ContractStatement',
-  'DebuggerStatement',
-  'DeclarativeExpression',
-  'DeclarativeExpressionList',
-  'DenominationLiteral',
-  'DoWhileStatement',
-  'EmptyStatement',
-  'EnumDeclaration',
-  'EventDeclaration',
-  'ExpressionStatement',
-  'ForInStatement',
-  'ForStatement',
-  'FunctionalAssemblyExpression',
-  'FunctionDeclaration',
-  'FunctionName',
-  'Identifier',
-  'IfStatement',
-  'ImportStatement',
-  'InformalParameter',
-  'InlineAssemblyBlock',
-  'InlineAssemblyStatement',
-  'IsStatement',
-  'LibraryStatement',
-  'Literal',
-  'MappingExpression',
-  'MemberExpression',
-  'ModifierArgument',
-  'ModifierDeclaration',
-  'ModifierName',
-  'Modifiers',
-  'NewExpression',
-  'PlaceholderStatement',
-  'PragmaStatement',
-  'Program',
-  'ReturnStatement',
-  'SequenceExpression',
-  'StateVariableDeclaration',
-  'StructDeclaration',
-  'ThisExpression',
-  'ThrowStatement',
-  'Type',
-  'UnaryExpression',
-  'UpdateExpression',
-  'UsingStatement',
-  'VariableDeclaration',
-  'VariableDeclarationTuple',
-  'VariableDeclarator',
-  'WhileStatement'].forEach(key => {
-    parse[key] = function dummyFunction() {};
-  });
-
-// Override the dummy functions where we know we can do better.
-
 parse.AssignmentExpression = function parseAssignmentExpression(contract, expression) {
   instrumenter.instrumentStatement(contract, expression);
   instrumenter.instrumentAssignmentExpression(contract, expression);
 };
 
-parse.ConditionalExpression = function parseConditionalExpression(contract, expression) {
-  instrumenter.instrumentStatement(contract, expression);
-  instrumenter.instrumentConditionalExpression(contract, expression);
-};
-
-parse.Modifiers = function parseModifier(contract, modifiers) {
-  if (modifiers) {
-    modifiers.forEach(modifier => {
-      parse[modifier.type](contract, modifier);
-    });
+parse.BlockStatement = function parseBlockStatement(contract, expression) {
+  for (let x = 0; x < expression.body.length; x++) {
+    instrumenter.instrumentLine(contract, expression.body[x]);
+    parse[expression.body[x].type] &&
+    parse[expression.body[x].type](contract, expression.body[x]);
   }
 };
 
-parse.ReturnStatement = function parseReturnStatement(contract, expression) {
-  instrumenter.instrumentStatement(contract, expression);
-};
-
-parse.NewExpression = function parseNewExpression(contract, expression) {
-  parse[expression.callee.type](contract, expression.callee);
-};
-
-parse.MemberExpression = function parseMemberExpression(contract, expression) {
-  parse[expression.object.type](contract, expression.object);
-};
-
 parse.CallExpression = function parseCallExpression(contract, expression) {
-  // It looks like in any given chain of call expressions, only the head callee is an Identifier
-  // node ... and we only want to instrument the statement once.
+  // In any given chain of call expressions, only the head callee is an Identifier node 
   if (expression.callee.type === 'Identifier') {
     instrumenter.instrumentStatement(contract, expression);
+    parse[expression.callee.type] &&
     parse[expression.callee.type](contract, expression.callee);
   } else {
+    parse[expression.callee.type] &&
     parse[expression.callee.type](contract, expression.callee);
   }
 };
 
-parse.UnaryExpression = function parseUnaryExpression(contract, expression) {
-  parse[expression.argument.type](contract, expression.argument);
+parse.ConditionalExpression = function parseConditionalExpression(contract, expression) {
+  instrumenter.instrumentStatement(contract, expression);
+  instrumenter.instrumentConditionalExpression(contract, expression);
 };
 
-parse.ThrowStatement = function parseThrowStatement(contract, expression) {
-  instrumenter.instrumentStatement(contract, expression);
+parse.ContractStatement = function ParseContractStatement(contract, expression) {
+  parse.ContractOrLibraryStatement(contract, expression);
 };
 
-parse.IfStatement = function parseIfStatement(contract, expression) {
-  instrumenter.instrumentStatement(contract, expression);
-  instrumenter.instrumentIfStatement(contract, expression);
-  // We can't instrument
-  // if (x==1)
-  //
-  // So don't count x==1 as a statement - just the if as a whole.
-  // parse[expression.test.type](contract, expression.test)
-  parse[expression.consequent.type](contract, expression.consequent);
-  if (expression.alternate) {
-    parse[expression.alternate.type](contract, expression.alternate);
+parse.ContractOrLibraryStatement = function parseContractOrLibraryStatement(contract, expression) {
+  // From the start of this contract statement, find the first '{', and inject there.
+  const injectionPoint = expression.start + contract.instrumented.slice(expression.start).indexOf('{') + 2;
+  if (contract.injectionPoints[injectionPoint]) {
+    contract.injectionPoints[expression.start + contract.instrumented.slice(expression.start).indexOf('{') + 2].push({
+      type: 'eventDefinition',
+    });
+  } else {
+    contract.injectionPoints[expression.start + contract.instrumented.slice(expression.start).indexOf('{') + 2] = [{
+      type: 'eventDefinition',
+    }];
+  }
+
+  if (expression.body) {
+    expression.body.forEach(construct => {
+      parse[construct.type] &&
+      parse[construct.type](contract, construct);
+    });
   }
 };
 
 parse.ExpressionStatement = function parseExpressionStatement(contract, content) {
+  parse[content.expression.type] &&
   parse[content.expression.type](contract, content.expression);
 };
 
-parse.VariableDeclarationTuple = function parseVariableDeclarationTuple(contract, expression) {
-  parse[expression.init.type](contract, expression.init);
-};
-
-parse.BlockStatement = function parseBlockStatement(contract, expression) {
-  for (let x = 0; x < expression.body.length; x++) {
-    instrumenter.instrumentLine(contract, expression.body[x]);
-    parse[expression.body[x].type](contract, expression.body[x]);
-  }
-};
-
-parse.VariableDeclaration = function parseVariableDeclaration(contract, expression) {
+parse.ForStatement = function parseForStatement(contract, expression) {
   instrumenter.instrumentStatement(contract, expression);
-  if (expression.declarations.length > 1) {
-    console.log('more than one declaration');
-  }
-  parse[expression.declarations[0].id.type](contract, expression.declarations[0].id);
-};
-
-parse.UsingStatement = function parseUsingStatement(contract, expression) {
-  parse[expression.for.type](contract, expression.for);
+  parse[expression.body.type] &&
+  parse[expression.body.type](contract, expression.body);
 };
 
 parse.FunctionDeclaration = function parseFunctionDeclaration(contract, expression) {
   parse.Modifiers(contract, expression.modifiers);
   if (expression.body) {
     instrumenter.instrumentFunctionDeclaration(contract, expression);
+
+    parse[expression.body.type] &&
     parse[expression.body.type](contract, expression.body);
   }
 };
 
-parse.ContractOrLibraryStatement = function parseContractOrLibraryStatement(contract, expression) {
-  // Inject our coverage event if we're covering
-  // This is harder because of where .start and .end represent, and how documented comments are validated
-  // by solc upon compilation. From the start of this contract statement, find the first '{', and inject
-  // there.
-  const injectionPoint = expression.start + contract.instrumented.slice(expression.start).indexOf('{') + 2;
-  if (contract.injectionPoints[injectionPoint]) {
-    contract.injectionPoints[expression.start + contract.instrumented.slice(expression.start).indexOf('{') + 2].push({
-      type: 'eventDefinition',
-    });
-  } else {
-    contract.injectionPoints[expression.start + contract.instrumented.slice(expression.start).indexOf('{') + 2] = [{
-      type: 'eventDefinition',
-    }];
-  }
+parse.IfStatement = function parseIfStatement(contract, expression) {
+  instrumenter.instrumentStatement(contract, expression);
+  instrumenter.instrumentIfStatement(contract, expression);
+  
+  parse[expression.consequent.type] &&
+  parse[expression.consequent.type](contract, expression.consequent);
 
-  if (expression.body) {
-    expression.body.forEach(construct => {
-      parse[construct.type](contract, construct);
-    });
+  if (expression.alternate) {
+    parse[expression.alternate.type] &&
+    parse[expression.alternate.type](contract, expression.alternate);
   }
 };
 
-parse.ContractStatement = function ParseContractStatement(contract, expression) {
+parse.LibraryStatement = function parseLibraryStatement(contract, expression) {
   parse.ContractOrLibraryStatement(contract, expression);
 };
 
-parse.LibraryStatement = function parseLibraryStatement(contract, expression) {
-  parse.ContractOrLibraryStatement(contract, expression);
+parse.MemberExpression = function parseMemberExpression(contract, expression) {
+  parse[expression.object.type] &&
+  parse[expression.object.type](contract, expression.object);
+};
+
+parse.Modifiers = function parseModifier(contract, modifiers) {
+  if (modifiers) {
+    modifiers.forEach(modifier => {
+      parse[modifier.type] && parse[modifier.type](contract, modifier);
+    });
+  }
 };
 
 parse.ModifierDeclaration = function parseModifierDeclaration(contract, expression) {
   instrumenter.instrumentFunctionDeclaration(contract, expression);
+  parse[expression.body.type] &&
   parse[expression.body.type](contract, expression.body);
 };
 
+parse.NewExpression = function parseNewExpression(contract, expression) {
+  parse[expression.callee.type] &&
+  parse[expression.callee.type](contract, expression.callee);
+};
+
 parse.Program = function parseProgram(contract, expression) {
   expression.body.forEach(construct => {
+    parse[construct.type] &&
     parse[construct.type](contract, construct);
   });
 };
 
-parse.WhileStatement = function parseWhileStatement(contract, expression) {
+parse.ReturnStatement = function parseReturnStatement(contract, expression) {
   instrumenter.instrumentStatement(contract, expression);
-  parse[expression.body.type](contract, expression.body);
 };
 
-parse.ForStatement = function parseForStatement(contract, expression) {
+parse.ThrowStatement = function parseThrowStatement(contract, expression) {
+  instrumenter.instrumentStatement(contract, expression);
+};
+
+parse.UnaryExpression = function parseUnaryExpression(contract, expression) {
+  parse[expression.argument.type] &&
+  parse[expression.argument.type](contract, expression.argument);
+};
+
+parse.UsingStatement = function parseUsingStatement(contract, expression) {
+  parse[expression.for.type] &&
+  parse[expression.for.type](contract, expression.for);
+};
+
+parse.VariableDeclaration = function parseVariableDeclaration(contract, expression) {
+  instrumenter.instrumentStatement(contract, expression);
+  parse[expression.declarations[0].id.type] &&
+  parse[expression.declarations[0].id.type](contract, expression.declarations[0].id);
+};
+
+parse.VariableDeclarationTuple = function parseVariableDeclarationTuple(contract, expression) {
+  parse[expression.init.type] &&
+  parse[expression.init.type](contract, expression.init);
+};
+
+parse.WhileStatement = function parseWhileStatement(contract, expression) {
   instrumenter.instrumentStatement(contract, expression);
+  parse[expression.body.type] &&
   parse[expression.body.type](contract, expression.body);
 };