Editing Macro (computer science) (section)

=== Early Lisp macros ===
Before Lisp had macros, it had so-called [[Fexpr|FEXPRs]], function-like operators whose inputs were not the values computed by the arguments but rather the syntactic forms of the arguments, and whose output were values to be used in the computation. In other words, FEXPRs were implemented at the same level as EVAL, and provided a window into the meta-evaluation layer. This was generally found to be a difficult model to reason about effectively.<ref>{{cite web|last=Marshall|first=Joe|title=untitled email|url=http://www.brinckerhoff.org/scraps/joe-marshall-on-FEXPRS-and-DEFMACRO.txt|access-date=May 3, 2012}}</ref>

In 1963, Timothy Hart proposed adding macros to Lisp 1.5 in [[AI Memo]] 57: MACRO Definitions for LISP.<ref>{{cite periodical |id=AIM-057 |title=MACRO Definitions for LISP |periodical=AI Memos |date=October 1963|hdl=1721.1/6111 |hdl-access=free |last1=Hart|first1=Timothy P.}}</ref>