Editing M-expression (section)

==Further development==
A [[CGOL]] (1977) was implemented in [[MacLisp]] and follows a similar goal of introducing Algol-like syntax with infix operators.<ref name="xl">{{cite web |last1=Lee |first1=Xah |title=LISP Infix Syntax Survey |url=http://xahlee.info/comp/lisp_sans_sexp.html}}</ref> It is known to work on [[Armed Bear Common Lisp]].<ref name="armed bear">[http://abcl-dev.blogspot.co.uk/2010/04/cgol-on-abcl.html CGOL on ABCL] ''Development of the Armed Bear Common Lisp implementation'' blog.</ref>

{{anchor|I-expression}}A more recent (circa 2003) variant is the ''I-expression'', which use [[off-side rule|indentation]] to indicate parentheses implicitly, and are thus in some ways intermediate between S-expressions and M-expressions.  I-expressions were introduced in [[Scheme Requests for Implementation|Scheme Request For Implementation]] 49 as an auxiliary syntax for [[Scheme (programming language)|Scheme]], but they have not been widely adopted.<ref>{{cite web |last1=Möller |first1=Egil |title=SRFI 49: Indentation-sensitive syntax |url=http://srfi.schemers.org/srfi-49/srfi-49.html |website=srfi.schemers.org |date=2003}}</ref>

{{anchor|T-expression}}A further development is the "sweet" ''t-expression'', which has [[infix operator]]s without precedence. Like I-expressions, t-expressions are only a simple transformation away from S-expressions, so that theoretically they can be used on any Lisp dialect and not interfere with features like macros.<ref>{{cite web |last1=Wheeler |first1=DA |title=SRFI 110: Sweet-expressions (t-expressions) |url=https://srfi.schemers.org/srfi-110/srfi-110.html |website=srfi.schemers.org |date=2013}}</ref>

Additional syntax-related include Apple's [[Dylan (programming language)|Dylan]] (Algol-like tokens) and [[Clojure]]'s addition of other literal syntaxes.<ref name="xl"/>