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import rdstdin, tables, sequtils, types, reader, printer
proc read(str: string): MalType = str.read_str
proc eval(ast: MalType, env: Table[string, MalType]): MalType
proc eval_ast(ast: MalType, env: Table[string, MalType]): MalType =
case ast.kind
of Symbol:
if not env.hasKey(ast.str):
raise newException(ValueError, "'" & ast.str & "' not found")
result = env[ast.str]
of List:
result = list ast.list.mapIt(MalType, it.eval(env))
of Vector:
result = vector ast.list.mapIt(MalType, it.eval(env))
of HashMap:
result = hash_map()
for k, v in ast.hash_map.pairs:
result.hash_map[k] = v.eval(env)
else:
result = ast
proc eval(ast: MalType, env: Table[string, MalType]): MalType =
case ast.kind
of List:
let el = ast.eval_ast(env)
el.list[0].fun(el.list[1 .. -1])
else:
ast.eval_ast(env)
proc print(exp: MalType): string = exp.pr_str
template wrapNumberFun(op: expr): expr =
fun proc(xs: varargs[MalType]): MalType = number op(xs[0].number, xs[1].number)
let repl_env = toTable({
"+": wrapNumberFun `+`,
"-": wrapNumberFun `-`,
"*": wrapNumberFun `*`,
"/": wrapNumberFun `div`,
})
proc rep(str: string): string =
str.read.eval(repl_env).print
while true:
try:
let line = readLineFromStdin("user> ")
echo line.rep
except:
echo getCurrentExceptionMsg()
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