1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
;;; Details on internal value representation.
;;; Copyright (C) 2014, 2015, 2017, 2018 Free Software Foundation, Inc.
;;;
;;; This library is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU Lesser General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; This library is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
;;; General Public License for more details.
;;;
;;; You should have received a copy of the GNU Lesser General Public License
;;; along with this program. If not, see <http://www.gnu.org/licenses/>.
(define-module (system base types internal)
#:export (;; Immediate tags.
%tc2-fixnum
%tc3-heap-object
%tc8-char
%tc16-false
%tc16-nil
%tc16-null
%tc16-true
%tc16-unspecified
%tc16-undefined
%tc16-eof
visit-immediate-tags
;; Heap object tags (cell types).
%tc1-pair
%tc3-struct
%tc7-symbol
%tc7-variable
%tc7-vector
%tc8-immutable-vector
%tc8-mutable-vector
%tc7-weak-vector
%tc7-string
%tc7-heap-number
%tc7-hash-table
%tc7-pointer
%tc7-fluid
%tc7-stringbuf
%tc7-dynamic-state
%tc7-frame
%tc7-keyword
%tc7-atomic-box
%tc7-syntax
%tc7-program
%tc7-vm-continuation
%tc7-bytevector
%tc7-weak-set
%tc7-weak-table
%tc7-array
%tc7-bitvector
%tc7-port
%tc7-smob
%tc16-bignum
%tc16-flonum
%tc16-complex
%tc16-fraction
visit-heap-tags))
;;; Commentary:
;;;
;;; Tag values used to represent Scheme values, internally to Guile.
;;;
;;; Code:
;;;
;;; Tags---keep in sync with libguile/tags.h!
;;;
(define-syntax define-tags
(lambda (x)
(define (id-append ctx a b)
(datum->syntax ctx (symbol-append (syntax->datum a) (syntax->datum b))))
(syntax-case x ()
((_ tag-set (name pred mask tag) ...)
#`(define-syntax #,(id-append #'tag-set #'visit- #'tag-set)
(lambda (x)
(define (introduce ctx id)
(datum->syntax ctx (syntax->datum id)))
(syntax-case x ()
((_ f)
#`(begin
(f #,(introduce #'f #'name)
#,(introduce #'f #'pred)
mask
tag)
...)))))))))
(define-tags immediate-tags
;; 321076543210 321076543210
(fixnum fixnum? #b11 #b10)
(heap-object heap-object? #b111 #b000)
(char char? #b11111111 #b00001100)
(false eq-false? #b111111111111 #b000000000100)
(nil eq-nil? #b111111111111 #b000100000100)
(null eq-null? #b111111111111 #b001100000100)
(true eq-true? #b111111111111 #b010000000100)
(unspecified unspecified? #b111111111111 #b100000000100)
(undefined undefined? #b111111111111 #b100100000100)
(eof eof-object? #b111111111111 #b101000000100)
;;(nil eq-nil? #b111111111111 #b000100000100)
;;(eol eq-null? #b111111111111 #b001100000100)
;;(false eq-false? #b111111111111 #b000000000100)
(null+nil null? #b110111111111 #b000100000100)
(false+nil false? #b111011111111 #b000000000100)
(null+false+nil nil? #b110011111111 #b000000000100))
(define-tags heap-tags
;; 321076543210 321076543210
(pair pair? #b1 #b0)
(struct struct? #b111 #b001)
;; For tc7 values, low bits 2 and 0 must be 1.
(symbol symbol? #b1111111 #b0000101)
(variable variable? #b1111111 #b0000111)
(vector vector? #b1111111 #b0001101)
(immutable-vector immutable-vector? #b11111111 #b10001101)
(mutable-vector mutable-vector? #b11111111 #b00001101)
(weak-vector weak-vector? #b1111111 #b0001111)
(string string? #b1111111 #b0010101)
(heap-number heap-number? #b1111111 #b0010111)
(hash-table hash-table? #b1111111 #b0011101)
(pointer pointer? #b1111111 #b0011111)
(fluid fluid? #b1111111 #b0100101)
(stringbuf stringbuf? #b1111111 #b0100111)
(dynamic-state dynamic-state? #b1111111 #b0101101)
(frame frame? #b1111111 #b0101111)
(keyword keyword? #b1111111 #b0110101)
(atomic-box atomic-box? #b1111111 #b0110111)
(syntax syntax? #b1111111 #b0111101)
;;(unused unused #b1111111 #b0111111)
(program program? #b1111111 #b1000101)
(vm-continuation vm-continuation? #b1111111 #b1000111)
(bytevector bytevector? #b1111111 #b1001101)
;;(unused unused #b1111111 #b1001111)
(weak-set weak-set? #b1111111 #b1010101)
(weak-table weak-table? #b1111111 #b1010111)
(array array? #b1111111 #b1011101)
(bitvector bitvector? #b1111111 #b1011111)
;;(unused unused #b1111111 #b1100101)
;;(unused unused #b1111111 #b1100111)
;;(unused unused #b1111111 #b1101101)
;;(unused unused #b1111111 #b1101111)
;;(unused unused #b1111111 #b1110101)
(smob smob? #b1111111 #b1110111)
(port port? #b1111111 #b1111101)
;;(unused unused #b1111111 #b1111111)
;(heap-number heap-number? #b1111111 #b0010111)
(bignum bignum? #b111111111111 #b000100010111)
(flonum flonum? #b111111111111 #b001000010111)
(complex compnum? #b111111111111 #b001100010111)
(fraction fracnum? #b111111111111 #b010000010111))
(define-syntax define-tag
(lambda (x)
(define (id-append ctx a b)
(datum->syntax ctx (symbol-append (syntax->datum a) (syntax->datum b))))
(define (def prefix name tag)
#`(define #,(id-append name prefix name) #,tag))
(syntax-case x ()
((_ name pred #b1 tag) (def #'%tc1- #'name #'tag))
((_ name pred #b11 tag) (def #'%tc2- #'name #'tag))
((_ name pred #b111 tag) (def #'%tc3- #'name #'tag))
((_ name pred #b1111111 tag) (def #'%tc7- #'name #'tag))
((_ name pred #b11111111 tag) (def #'%tc8- #'name #'tag))
;; Only 12 bits of mask but for historic reasons these are called
;; tc16 values.
((_ name pred #b111111111111 tag) (def #'%tc16- #'name #'tag))
((_ name pred mask tag)
#`(begin
(define #,(id-append #'name #'name #'-mask) mask)
(define #,(id-append #'name #'name #'-tag) tag))))))
(visit-immediate-tags define-tag)
(visit-heap-tags define-tag)
;; See discussion in tags.h and boolean.h.
(eval-when (expand)
(let ()
(visit-immediate-tags define-tag)
(define (exactly-one-bit-set? x)
(and (not (zero? x)) (zero? (logand x (1- x)))))
(define (exactly-two-bits-set? x)
(exactly-one-bit-set? (logand x (1- x))))
(define (bits-differ-in-exactly-one-bit-position? a b)
(exactly-one-bit-set? (logxor a b)))
(define (bits-differ-in-exactly-two-bit-positions? a b)
(exactly-two-bits-set? (logxor a b)))
(define (common-bits a b)
(values (logand #xfff (lognot (logxor a b))) (logand a b)))
(unless (bits-differ-in-exactly-one-bit-position? %tc16-null %tc16-nil)
(error "expected #nil and '() to differ in exactly one bit position"))
(unless (bits-differ-in-exactly-one-bit-position? %tc16-false %tc16-nil)
(error "expected #f and '() to differ in exactly one bit position"))
(unless (bits-differ-in-exactly-two-bit-positions? %tc16-false %tc16-null)
(error "expected #f and '() to differ in exactly two bit positions"))
(call-with-values (lambda () (common-bits %tc16-null %tc16-nil))
(lambda (mask tag)
(unless (= mask null+nil-mask) (error "unexpected mask for null?"))
(unless (= tag null+nil-tag) (error "unexpected tag for null?"))))
(call-with-values (lambda () (common-bits %tc16-false %tc16-nil))
(lambda (mask tag)
(unless (= mask false+nil-mask) (error "unexpected mask for false?"))
(unless (= tag false+nil-tag) (error "unexpected tag for false?"))))
(call-with-values (lambda () (common-bits %tc16-false %tc16-null))
(lambda (mask tag)
(unless (= mask null+false+nil-mask) (error "unexpected mask for nil?"))
(unless (= tag null+false+nil-tag) (error "unexpected tag for nil?"))))))
|