Manual Notation

This manual uses a small number of typographic conventions:

Monospaced font (Courier 12) is used to indicate text that should appear verbatim in programs.
Italic font is used to name parameters, placeholders for actual program text.
References to entries in the BNF are given the same name as in the BNF, and are followed by a subscripted italic _bnf.
Bold is used for the first use of terms.
Bold is also used for meta-syntactic punctuation, as follows:
- [ ] Contents are optional
- { } Contents appear once
- { }* Contents appear zero or more times
- { }+ Contents appear one or more times
- | A choice between the item on the left of the vertical bar and the item on the right of the vertical bar, but not both.

If a comma appears between a right curly brace and the following asterisk or plus sign, it indicates that multiple occurrences of the contents are separated by a comma. There is no comma after the last occurrence.

If a semicolon appears between a right curly brace and the following asterisk or plus sign, it indicates that multiple occurrences of the contents are separated by a semicolon. A semicolon following the last occurrence is optional.

Sample Dylan code is shown in small monospaced font. When the return value of an expression is shown, it is preceded by an ⇒.

Chapter 10, Macros, and Appendix A, BNF, each use a distinctive notation, described at the start of the chapter and appendix.