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| @@ -1961,6 +1961,19 @@ · 1960 unmodified lines | ||
| 1961 | 1961 | (list '$trycatch try catch)) |
| 1962 | 1962 | |
| 1963 | 1963 | (defmacro (letrec binds . body) |
| 1964 | + «Same as the second form of `let` but each of the binding expressions | |
| 1965 | + may reference any of the variables bound, before or after. | |
| 1966 | + | |
| 1967 | + Examples: | |
| 1968 | + | |
| 1969 | + (letrec ((a (λ () 1)) | |
| 1970 | + (b (λ () (+ (c) 1))) | |
| 1971 | + (c (λ () (+ (a) 1)))) | |
| 1972 | + (list (a) (b) (c))) | |
| 1973 | + ; ↳ (1 3 2)» | |
| 1974 | + :doc-group syntax | |
| 1975 | + :doc-see let | |
| 1976 | + :doc-see let* | |
| 1964 | 1977 | (unless (cons? body) |
| 1965 | 1978 | (arg-error "missing body")) |
| 1966 | 1979 | `((λ ,(map car binds) |
| @@ -1969,6 +1982,19 @@ · 2 unmodified lines | ||
| 1969 | 1982 | ,.(map void binds))) |
| 1970 | 1983 | |
| 1971 | 1984 | (defmacro (let* binds . body) |
| 1985 | + «Same as the second form of `let` but each of the binding expressions | |
| 1986 | + may reference any of the varibles bound previously. | |
| 1987 | + | |
| 1988 | + Examples: | |
| 1989 | + | |
| 1990 | + (let* ((a 1) | |
| 1991 | + (b (+ a 1)) | |
| 1992 | + (c (+ b 1))) | |
| 1993 | + c) | |
| 1994 | + ; ↳ 3» | |
| 1995 | + :doc-group syntax | |
| 1996 | + :doc-see let | |
| 1997 | + :doc-see letrec | |
| 1972 | 1998 | (unless (cons? body) |
| 1973 | 1999 | (arg-error "missing body")) |
| 1974 | 2000 | `((λ (,(caar binds)) |
| @@ -1978,6 +2004,29 @@ · 3 unmodified lines | ||
| 1978 | 2004 | ,(aref binds 0 1))) |
| 1979 | 2005 | |
| 1980 | 2006 | (defmacro (let binds . body) |
| 2007 | + «Bind variables and execute a series of expression that use | |
| 2008 | + these bindings, return the result of the last expression. | |
| 2009 | + | |
| 2010 | + The first form `(let id ((… ) …) …)`, which is called | |
| 2011 | + "named let", allows referencing the resulting lambda within | |
| 2012 | + the expressions following the bindings to aid with recursive | |
| 2013 | + calls. | |
| 2014 | + | |
| 2015 | + Examples: | |
| 2016 | + | |
| 2017 | + (let loop ((a (iota 3 1))) ; first form | |
| 2018 | + (when a | |
| 2019 | + (princ (car a)) | |
| 2020 | + (loop (cdr a)))) | |
| 2021 | + ; ‼ 123 | |
| 2022 | + ; ↳ NIL | |
| 2023 | + | |
| 2024 | + (let ((a 123) (b 456)) ; second form | |
| 2025 | + (+ a b)) | |
| 2026 | + ; ↳ 579» | |
| 2027 | + :doc-group syntax | |
| 2028 | + :doc-see let* | |
| 2029 | + :doc-see letrec | |
| 1981 | 2030 | (unless (cons? body) |
| 1982 | 2031 | (arg-error "missing body")) |
| 1983 | 2032 | (let ((lname NIL)) |
| @@ -2004,6 +2053,8 @@ · 20 unmodified lines | ||
| 2004 | 2053 | thelambda) |
| 2005 | 2054 | theargs)))) |
| 2006 | 2055 | |
| 2056 | +(defdoc (let id binds . body)) | |
| 2057 | + | |
| 2007 | 2058 | (defmacro (cond . clauses) |
| 2008 | 2059 | (def (1arg-lambda? func) |
| 2009 | 2060 | (and (cons? func) |