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|
readline = require "./node_readline.coffee"
types = require "./types.coffee"
reader = require "./reader.coffee"
printer = require "./printer.coffee"
Env = require("./env.coffee").Env
# read
READ = (str) -> reader.read_str str
# eval
eval_ast = (ast, env) ->
if types._symbol_Q(ast) then env.get ast
else if types._list_Q(ast) then ast.map((a) -> EVAL(a, env))
else if types._vector_Q(ast)
types._vector(ast.map((a) -> EVAL(a, env))...)
else if types._hash_map_Q(ast)
new_hm = {}
new_hm[k] = EVAL(ast[k],env) for k,v of ast
new_hm
else ast
EVAL = (ast, env) ->
#console.log "EVAL:", printer._pr_str ast
if !types._list_Q ast then return eval_ast ast, env
# apply list
[a0, a1, a2, a3] = ast
switch a0.name
when "def!"
env.set(a1, EVAL(a2, env))
when "let*"
let_env = new Env(env)
for k,i in a1 when i %% 2 == 0
let_env.set(a1[i], EVAL(a1[i+1], let_env))
EVAL(a2, let_env)
else
[f, args...] = eval_ast ast, env
f(args...)
# print
PRINT = (exp) -> printer._pr_str exp, true
# repl
repl_env = new Env()
rep = (str) -> PRINT(EVAL(READ(str), repl_env))
repl_env.set types._symbol("+"), (a,b) -> a+b
repl_env.set types._symbol("-"), (a,b) -> a-b
repl_env.set types._symbol("*"), (a,b) -> a*b
repl_env.set types._symbol("/"), (a,b) -> a/b
# repl loop
while (line = readline.readline("user> ")) != null
continue if line == ""
try
console.log rep line
catch exc
continue if exc instanceof reader.BlankException
if exc.stack then console.log exc.stack
else console.log exc
# vim: ts=2:sw=2
|
