Editing Scheme (programming language) (section)

===Standard forms===
This table describes the standard forms in Scheme. Some forms appear in more than one row because they cannot easily be classified into a single function in the language.

Forms marked "L" in this table are classed as derived "library" forms in the standard and are often implemented as macros using more fundamental forms in practice, making the task of implementation much easier than in other languages.

{| class="wikitable"
|+ Standard forms in the language R5RS Scheme
! Purpose                !!   Forms
|-
| Definition             || {{mono|define}}
|-
| Binding constructs     || {{mono|lambda, do (L), let (L), let* (L), letrec (L)}}
|-
| Conditional evaluation || {{mono|if, cond (L), case (L), and (L), or (L)}}
|-
| Sequential evaluation  || {{mono|begin (*)}}
|-
| Iteration              || {{mono|lambda, do (L), named let (L)}}
|-
| Syntactic extension    || {{mono|define-syntax, let-syntax, letrec-syntax, syntax-rules (R5RS), syntax-case (R6RS)}}
|-
| Quoting                || {{mono|quote('), unquote(,), quasiquote(`), unquote-splicing(,@)}}
|-
| Assignment             || {{mono|set!}}
|-
| Delayed evaluation     || {{mono|delay (L)}}
|}

While <code>begin</code> is defined as a library syntax in R5RS, the expander must know about it to achieve the splicing function. In R6RS it is no longer a library syntax.