diff options
Diffstat (limited to 'go/src/step3_env')
| -rw-r--r-- | go/src/step3_env/step3_env.go | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/go/src/step3_env/step3_env.go b/go/src/step3_env/step3_env.go index 6241eff..3d35dbe 100644 --- a/go/src/step3_env/step3_env.go +++ b/go/src/step3_env/step3_env.go @@ -70,30 +70,36 @@ func EVAL(ast MalType, env Env) (MalType, error) { // apply list a0 := ast.(List).Val[0] - if !Symbol_Q(a0) { - return nil, errors.New("attempt to apply on non-symbol '" + - printer.Pr_str(a0, true) + "'") + var a1 MalType = nil; var a2 MalType = nil + switch len(ast.(List).Val) { + case 1: + a1 = nil; a2 = nil + case 2: + a1 = ast.(List).Val[1]; a2 = nil + default: + a1 = ast.(List).Val[1]; a2 = ast.(List).Val[2] } - switch a0.(Symbol).Val { + a0sym := "__<*fn*>__" + if Symbol_Q(a0) { a0sym = a0.(Symbol).Val } + switch a0sym { case "def!": - a1 := ast.(List).Val[1]; a2 := ast.(List).Val[2] res, e := EVAL(a2, env) if e != nil { return nil, e } return env.Set(a1.(Symbol).Val, res), nil case "let*": - a1 := ast.(List).Val[1]; a2 := ast.(List).Val[2] - let_env := NewEnv(&env, nil, nil) + let_env, e := NewEnv(&env, nil, nil) + if e != nil { return nil, e } arr1, e := GetSlice(a1) if e != nil { return nil, e } for i := 0; i < len(arr1); i+=2 { if !Symbol_Q(arr1[i]) { return nil, errors.New("non-symbol bind value") } - exp, e := EVAL(arr1[i+1], let_env) + exp, e := EVAL(arr1[i+1], *let_env) if e != nil { return nil, e } let_env.Set(arr1[i].(Symbol).Val, exp) } - return EVAL(a2, let_env) + return EVAL(a2, *let_env) default: el, e := eval_ast(ast, env) if e != nil { return nil, e } @@ -109,14 +115,14 @@ func PRINT(exp MalType) (MalType, error) { } -var repl_env = NewEnv(nil, nil, nil) +var repl_env, _ = NewEnv(nil, nil, nil) // repl func rep(str string) (MalType, error) { var exp MalType var e error if exp, e = READ(str); e != nil { return nil, e } - if exp, e = EVAL(exp, repl_env); e != nil { return nil, e } + if exp, e = EVAL(exp, *repl_env); e != nil { return nil, e } if exp, e = PRINT(exp); e != nil { return nil, e } return exp, nil } |
