application/octet-stream
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3.62 KB
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84 lines
;;; Nujel - Copyright (C) 2020-2021 - Benjamin Vincent Schulenburg
;;; This project uses the MIT license, a copy should be included under /LICENSE
;;;
;;; Mostly macros implementing different control flow constructs
[defmacro if-not [pred then else]
`[if ~pred ~else ~then]]
[defmacro when-not [pred . body]
"Evalutes to BODY if PRED is false"
`[if ~pred #nil [do ~@body]]]
[defmacro when [pred . body]
"Evalutes to BODY if PRED is true"
`[if ~pred [do ~@body] #nil]]
[def case [let*
[defn case/clauses/multiple [key-sym cases]
[when cases
[cons [list '= key-sym [car cases]]
[case/clauses/multiple key-sym [cdr cases]]]]]
[defn case/clauses [key-sym clauses]
[when clauses
[if [= [caar clauses] 'otherwise]
[cons 'do [cdar clauses]]
[list 'if
[if [pair? [caar clauses]]
[if [and [= [car [caar clauses]] 'quote]
[last? [cdr [caar clauses]]]
[symbol? [cadr [caar clauses]]]]
[list '= key-sym [caar clauses]]
[cons 'or [case/clauses/multiple key-sym [caar clauses]]]]
[list '= key-sym [caar clauses]]]
[cons 'do [cdar clauses]]
[case/clauses key-sym [cdr clauses]]]]]]
[defmacro case [key-form . clauses]
[def key-sym [gensym]]
[list 'let*
[list 'def key-sym key-form]
[case/clauses key-sym clauses]]]]]
[defmacro cond body
"Contains multiple cond clauses"
[when [and body [caar body]]
[list 'if
[caar body]
[cons 'do [cdar body]]
[macro-apply cond [cdr body]]]]]
[defmacro dotimes [binding . body]
"binding => [name n result-form]"
"Repeatedly executes body with name bound to integers from 0 through n-1. Returns result-form or #nil."
[def sym [car binding]]
[typecheck/only sym :symbol]
[def times [cadr binding]]
[def result-form [caddr binding]]
`[let [[~sym 0]]
[while [< ~sym ~times]
~@body
[set! ~sym [inc/int ~sym]]]
~result-form]]
[defmacro doseq [for-loop . body]
"[doseq [l [list 1 2 3 4] result-form] [println l]]"
[def symbol-name [gensym]]
`[let [[~symbol-name ~[cadr for-loop]]]
[while ~symbol-name
[when-not [pair? ~symbol-name] [exception :type-error "Improper list detected, please provide a proper list instead" ~[cadr for-loop]]]
[typecheck/only ~symbol-name :pair]
[def ~[car for-loop] [car ~symbol-name]]
~@body
[cdr! ~symbol-name]]
~[caddr for-loop]]]
[def -> [let*
[defn thread/-> [init fun]
[if-not fun init
[if [pair? [car fun]]
`[~[caar fun] ~[thread/-> init [cdr fun]] ~@[cdar fun]]
[list [car fun] [thread/-> init [cdr fun]]]]]]
[defmacro -> [init . fun]
"Thread init as the first argument through every function in fun"
[thread/-> init [reverse fun]]]]]
