objc/env.m

   1 #import <Foundation/Foundation.h>
   2
   3 #import "types.h"
   4 //#import "env.h"
   5
   6 @implementation Env
   7
   8 @synthesize data = _data;
   9 @synthesize outer = _outer;
  10
  11 - (id)initWithBindings:(Env *)outer binds:(NSArray *)binds exprs:(NSArray *)exprs {
  12     self = [super init];
  13     if (self) {
  14         _outer = outer;
  15         _data = [NSMutableDictionary dictionary];
  16
  17         for (int i=0; i < [binds count]; i++) {
  18             if ([(NSString *)binds[i] isEqualTo:@"&"]) {
  19                 if ([exprs count] > i) {
  20                     NSRange r = NSMakeRange(i, [exprs count] - i);
  21                     _data[binds[i+1]] = [exprs subarrayWithRange:r];
  22                 } else {
  23                     _data[binds[i+1]] = @[];
  24                 }
  25                 break;
  26             } else {
  27                 _data[binds[i]] = exprs[i];
  28             }
  29         }
  30     }
  31     return self;
  32 }
  33
  34 - (id)initWithOuter:(Env *)outer {
  35     return [self initWithBindings:outer binds:@[] exprs:@[]];
  36 }
  37
  38 - (id)init {
  39     return [self initWithBindings:nil binds:@[] exprs:@[]];
  40 }
  41
  42 + (id)fromOuter:(Env *)outer {
  43     return [[Env alloc] initWithOuter:outer];
  44 }
  45
  46 + (id)fromBindings:(Env *)outer binds:(NSArray *)binds exprs:(NSArray *)exprs {
  47     return [[Env alloc] initWithBindings:outer binds:binds exprs:exprs];
  48 }
  49
  50 - (NSObject *) set:(MalSymbol *)key val:(NSObject *)val {
  51     _data[key] = val;
  52     return val;
  53 }
  54
  55 - (Env *) find:(MalSymbol *)key {
  56     if (_data[key]) {
  57         return self;
  58     } else if (_outer) {
  59         Env * e = _outer;
  60         return [e find:key];
  61     } else {
  62         return nil;
  63     }
  64 }
  65
  66 - (NSObject *) get:(MalSymbol *)key {
  67     Env * e = [self find:key];
  68     if (e) {
  69         return e.data[key];
  70     } else {
  71         @throw [NSString stringWithFormat:@"'%@' not found", key];
  72     }
  73 }
  74
  75 @end