The quiz will made available online immediately after class on March 18, and must be turned in by 11:59 p.m. America/Los Angeles time, on March 22. You are allowed only 90 minutes to work on it, but you can choose any 90-minute period in the allotted range.

You need to know:

• A little bit of Computer Science History
• How to write grammars
• Difference between variables and alphabet symbols in a grammar
• Difference between capitalized and non-capitalized variables
• How to give a parse tree for a given derivation in a grammar
• What it means for a grammar to be ambiguous
• How to read and write grammars for simple formal languages and for little programming languages
• Going between prose descriptions of languages and their grammars (both ways)
• What a context-free grammar is
• A sense of what kind of grammars are context-free and which are not
• How to read and make syntax diagrams
• The difference between lexical analysis and parsing
• What tokens are
• The difference between lexical and phrase rules
• Differences between CST and AST and how to draw them
• What the frontier of the CST is made up of
• A lot about ambiguity
• A lot about precedence
• Associativity (L, R, None, or indeterminate)
• The use of non-associativity, esp. in relational operators
• How can we make -2**2 illegal (like it is in JS)
• How to write an Ohm grammar
• Ordering of rules in Ohm (“big” things first)
• Using Ohm: ohm.grammar, ohm.createSemantics
• How to draw an abbreviated AST
• How to draw an internal representation of an AST
• Why we only use context free grammars to define programming languages
• The difference between a compiler and an interpreter
• The phases of a traditional compiler
• How modern compilers are structured (Anders Hejlsberg video)
• AOT vs JIT
• What is syntax, what is static semantics
• How to distinguish syntax errors from contextual errors
• Given an English description of a language figure out which checks are syntactic vs semantic
• Given an Ohm grammar, explain what it is saying (at a high level)
• How to write an AST for sophisticated JavaScript

Things to do in preparation:

• Review the course notes
• Review Ohm docs
• Do whichever reinforcement problems that seem to make sense for this class, as well as all of the recall questions at the bottom of the relevant pages of notes.
• Practice writing grammars
• Write your own ASTs for snippets of JavaScript (Practice with friends)
• Study the Bella and Carlos grammars, and make sure you know what each are saying
• Make a big list of things that are semantic errors (and not syntax errors) in high-level languages you already know (e.g. JavaScript, Swift, Python, C++, Java, etc.)

If you work on the practice problems that sufficiently look like they cover material we’ve discussed in class, you should be fine. I recommend studying in groups with friends. Take over a whiteboard. Bring food. Play some nice background music. Studying should be fun and not stressful. You should learn things together.