Go Code Typing

Channel Arrows

Sends, receives, and directional chan types

Pointers & Receivers

Star, ampersand, and nil checks on methods

Composite Literals & Tags

Slice, map, and struct literals with backtick tags

Error Wrapping & Verbs

%w wrapping plus %v %s %q %T formatting

Checkpoint: Symbol Fluency

Every Go glyph cluster from this module in one longer drill

Keywords

Go reserved words drilled in rhythm

Declarations

Structs, interfaces, and functions

Interfaces & Embedding

Small interfaces, embedding, and compile-time checks

defer, panic & recover

Cleanup that runs no matter which path returns

Idiomatic Patterns

Common Go one-liners

Generics & Constraints

Type parameters with [T any] and comparable

Checkpoint: Keywords & Idioms

A rate limiter that mixes this module's material

Control Flow

Error handling, loops, and type switches

Functions & Methods

Idiomatic Go functions

Mutex-Guarded Counter

A concurrency-safe type with a constructor and methods

Custom Error Types

Sentinel errors, an Error() method, and errors.As

Maps & Slices

Grouping with append and ranking with sort.Slice

Realistic Snippet

HTTP handler with JSON and context

Table-Driven Tests

Subtests with t.Run over a case table

Checkpoint: Real Snippets

A bufio.Scanner log filter mixing this module's material

Speed Run: HTTP Middleware

Handler chaining typed end to end without stopping

Speed Run: Context Fan-Out

WaitGroup fan-out under a WithTimeout deadline

Speed Run: Ranking Report

sort.Slice over aggregated totals at full pace

Speed Run: JSON Round Trip

Marshal and unmarshal with struct tags and wrapped errors

Speed Run: Ticker & Shutdown

A select loop batching work until ctx.Done()

Checkpoint: Sustained Speed

A server with graceful shutdown typed in one continuous run

Assessment Sim 1: Word Frequency

A complete stdin word counter with a ranked printout

Assessment Sim 2: RPN Calculator

A complete stack evaluator with explicit error returns

Assessment Sim 3: Inventory Ledger

A full stock-movement program that rejects oversell

Assessment Sim 4: Worker Pool

A channel fan-out with WaitGroup and collected results

Checkpoint: Go Mastery Final

A tabwriter latency report -- the course's graded final