Codepurify Template Syntax

Codepurify uses {| ... |} tags to generate deterministic code from structured data.

Delimiters

All syntax is defined inside:

These delimiters define expressions, blocks, and comments.

Expressions

Expressions output values directly into the generated code.

Rules:

• Inline only (no automatic spacing or newlines)
• Must resolve to a value at runtime
• No side effects

Comments

Comments are ignored and not included in output.

Regular comment

Documentation comment

Blocks

Blocks control rendering behavior. Each block has an opening and closing tag.

if

Renders content when a condition is true.

Supports an optional else branch.

Rules:

• Must close with {|/if|}
• May contain one {|else|}

unless

Renders content when a condition is false.

Equivalent to a negated if.

Rules:

• Must close with {|/unless|}
• May contain one {|else|}

else

Defines a fallback branch.

Rules:

• Only valid inside if or unless
• Cannot exist alone
• Only one allowed per block
• Does not have a closing tag

loop

Repeats content for each item in a collection.

Rules:

• Must close with {|/loop|}
• No automatic separators or formatting
• Output is a direct concatenation of each iteration

with

Changes the current context inside a block.

Rules:

• Must close with {|/with|}
• Only affects name resolution
• Does not modify data

ignore

Disables all template processing inside the block.

Rules:

• Must close with {|/ignore|}
• Everything inside is treated as plain text
• No expressions or blocks are evaluated

Formatting

Codepurify does not apply formatting automatically.

Templates control:

• newlines
• spacing
• indentation

Principle:

Output formatting is explicit and defined by the template.

Syntax Summary

• {|value|} → expression
• {|# ... #|} → comment
• {|* ... *|} → documentation comment
• {|if ...|} / {|/if|} → conditional
• {|unless ...|} / {|/unless|} → inverse conditional
• {|else|} → branch
• {|loop ...|} / {|/loop|} → iteration
• {|with ...|} / {|/with|} → context scope
• {|ignore|} / {|/ignore|} → literal block

Design Principles

Codepurify syntax is intentionally minimal:

• deterministic
• explicit
• easy to validate
• independent of target language formatting

Templates define structure. Formatting remains under user control or external tooling.