effective-go

Effective Go — Compact Rules

Apply these rules when writing or reviewing Go. Prefer standard library examples and gofmt. Document is from 2009; core language idioms still hold (generics/modules are outside its scope).

Formatting

• Always run gofmt / go fmt. No exceptions.
• Tabs for indentation. Spaces only if forced.
• No line-length limit; wrap and indent with an extra tab if needed.
• Fewer parentheses than C/Java: no parens around if/for/switch conditions.
• Opening brace of control structures stays on the same line (semicolon insertion rule).

Commentary

• Prefer // line comments. Use /* */ mainly for package docs or disabling large blocks.
• Doc comments sit immediately before the declaration they document (no blank line).
• Comment the why, not the what.

Names

• Packages: short, lowercase, single-word, no underscores or MixedCaps. Base name of the directory. Avoid util/common.
• Exported names start with uppercase; unexported with lowercase.
• Getters: for field owner the method is Owner(), not GetOwner(). Setter is SetOwner().
• Interfaces: one-method interfaces often named Method + er (Reader, Writer, Stringer). Honor canonical names/signatures (Read, Write, String, Close…).
• Multi-word names use MixedCaps / mixedCaps, never underscores.
• Short names for short scopes (i, r, err, ctx). Longer names for longer-lived or exported identifiers.
• Avoid stuttering with the package name (bufio.Reader not bufio.BufReader).

Semicolons

• Almost never written; lexer inserts them. Consequence: opening { of if/for/switch/select must be on the same line.

Control structures

• No do/while; only for (three forms: C-style, while-style, infinite).
• if/switch may have an init statement.
• Prefer early return; omit else after a terminating statement (return/break/continue/goto).
• Happy path stays at the lowest indentation.
• switch has no automatic fall-through; cases can be comma-separated lists. Expressionless switch acts as if-else chain.
• Type switch: switch v := x.(type).
• break/continue accept optional labels.