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Lecture Notes 25: Intro to Parsing.

Objectives

During this module, we'll explore the idea of parsing and the following elements:

• markup languages that are easy to parse
• Java structures that help with parsing
• parsing concepts like "tags", "tokens", etc.

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Before Starting

If you do not have your Codio course ready, use any text editor or simple IDE. Some possibilities are:

• Write using Sublime; Compile and run in the Terminal
• Use IDEs like: IntelliJ, DrJava, or JGrasp

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The rules matter

Dear John:

I want a man who knows what love is all about. You are generous, kind, thoughtful. People who are not like you admit to being useless and inferior. You have ruined me for other men. I yearn for you. I have no feelings whatsoever when we’re apart. I can be forever happy–will you let me be yours?

Activity 1: Answer the following questions:

• who is the sender of this letter and who is the recipient?
• is the letter a positive one? DOes the sender feel "good feelings" towards the recipient?
• How do you know these things?

Activity 2:

(Click to expand!)

Dear John:

I want a man who knows what love is. All about you are generous, kind, thoughtful people, who are not like you. Admit to being useless and inferior. You have ruined me. For other men, I yearn. For you, I have no feelings whatsoever. When we’re apart, I can be forever happy. Will you let me be?

Answer the following questions:

• is the letter a positive one? Does the sender feel "good feelings" towards the recipient?
• How do you know these things? What changed?

One more

Activity 3:

(Click to expand!)

Let's eat, grandma

How could that possibly go wrong?

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A CS example

Please open the following link in a new tab: map

Steps:

1. Press Export in the top left
2. Press the blue Export button
3. save as "map.osm"
4. open in any text editor (I use Sublime)

Activity 4: You will be placed in Breakout groups and asked to analyze the code to explain the main. We'll do multiple separate sessions to explain:

• getOsmData
• numEntries
• bounds
• getAttribute
• nodeInfo
• getWayName (not implemented)

Parsing language

Check this video (use headphones or at home): parsing grammar

Parsing as part of compilation

Check this video (use headphones or at home): parsing for compilation

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On to Review

Anyone with review requests may put them forth now!