forked from sql-machine-learning/sqlflow
/
sql.y
396 lines (348 loc) · 8.46 KB
/
sql.y
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
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
%{
package sql
import (
"fmt"
"log"
"sort"
"strings"
)
/* expr defines an expression as a Lisp list. If len(val)>0,
it is an atomic expression, in particular, NUMBER, IDENT,
or STRING, defined by typ and val; otherwise, it is a
Lisp S-expression. */
type expr struct {
typ int
val string
sexp exprlist
}
type exprlist []*expr
/* construct an atomic expr */
func atomic(typ int, val string) *expr {
return &expr{
typ : typ,
val : val,
}
}
/* construct a funcall expr */
func funcall(name string, oprd exprlist) *expr {
return &expr{
sexp : append(exprlist{atomic(IDENT, name)}, oprd...),
}
}
/* construct a unary expr */
func unary(typ int, op string, od1 *expr) *expr {
return &expr{
sexp : append(exprlist{atomic(typ, op)}, od1),
}
}
/* construct a binary expr */
func binary(typ int, od1 *expr, op string, od2 *expr) *expr {
return &expr{
sexp : append(exprlist{atomic(typ, op)}, od1, od2),
}
}
/* construct a variadic expr */
func variadic(typ int, op string, ods exprlist) *expr {
return &expr{
sexp : append(exprlist{atomic(typ, op)}, ods...),
}
}
type extendedSelect struct {
extended bool
train bool
standardSelect
trainClause
inferClause
}
type standardSelect struct {
fields []string
tables []string
where *expr
limit string
}
type trainClause struct {
estimator string
attrs attrs
columns exprlist
label string
save string
}
type attrs map[string]*expr
type inferClause struct {
model string
}
var parseResult extendedSelect
func attrsUnion(as1, as2 attrs) attrs {
for k, v := range as2 {
if _, ok := as1[k]; ok {
log.Panicf("attr %q already specified", as2)
}
as1[k] = v
}
return as1
}
%}
%union {
val string /* NUMBER, IDENT, STRING, and keywords */
flds []string
tbls []string
expr *expr
expl exprlist
atrs attrs
eslt extendedSelect
slct standardSelect
tran trainClause
infr inferClause
}
%type <eslt> select_stmt
%type <slct> select
%type <tran> train_clause
%type <infr> infer_clause
%type <flds> fields
%type <tbls> tables
%type <expr> expr funcall column
%type <expl> exprlist pythonlist columns
%type <atrs> attr
%type <atrs> attrs
%token <val> SELECT FROM WHERE LIMIT TRAIN INFER WITH COLUMN LABEL INTO
%token <val> IDENT NUMBER STRING
%left <val> AND OR
%left <val> '>' '<' '=' GE LE
%left <val> '+' '-'
%left <val> '*' '/' '%'
%left <val> NOT
%left <val> POWER /* think about the example "NOT base ** -3" */
%left <val> UMINUS
%%
select_stmt
: select ';' {
parseResult.extended = false
parseResult.standardSelect = $1
}
| select train_clause ';' {
parseResult.extended = true
parseResult.train = true
parseResult.standardSelect = $1
parseResult.trainClause = $2
}
| select infer_clause ';' {
parseResult.extended = true
parseResult.train = false
parseResult.standardSelect = $1
parseResult.inferClause = $2
}
;
select
: SELECT fields { $$.fields = $2 }
| select FROM tables { $$.tables = $3 }
| select LIMIT NUMBER { $$.limit = $3 }
| select WHERE expr { $$.where = $3 }
;
train_clause
: TRAIN IDENT WITH attrs COLUMN columns LABEL IDENT INTO IDENT {
$$.estimator = $2
$$.attrs = $4
$$.columns = $6
$$.label = $8
$$.save = $10
}
;
infer_clause
: INFER IDENT { $$.model = $2 }
;
fields
: '*' { $$ = $$[:0] }
| IDENT { $$ = append($$, $1) }
| fields ',' IDENT { $$ = append($$, $3) }
;
column
: '*' { $$ = atomic(IDENT, "*") }
| IDENT { $$ = atomic(IDENT, $1) }
| funcall { $$ = $1 }
;
columns
: column { $$ = exprlist{$1} }
| columns ',' column { $$ = append($1, $3) }
;
tables
: IDENT { $$ = []string{$1} }
| tables ',' IDENT { $$ = append($1, $3) }
;
attr
: IDENT '=' expr { $$ = attrs{$1 : $3} }
;
attrs
: attr { $$ = $1 }
| attrs ',' attr { $$ = attrsUnion($1, $3) }
;
funcall
: IDENT '(' ')' { $$ = funcall($1, nil) }
| IDENT '(' exprlist ')' { $$ = funcall($1, $3) }
;
exprlist
: expr { $$ = exprlist{$1} }
| exprlist ',' expr { $$ = append($1, $3) }
;
pythonlist
: '[' ']' { $$ = nil }
| '[' exprlist ']' { $$ = $2 }
;
expr
: NUMBER { $$ = atomic(NUMBER, $1) }
| IDENT { $$ = atomic(IDENT, $1) }
| STRING { $$ = atomic(STRING, $1) }
| pythonlist { $$ = variadic('[', "square", $1) }
| '(' expr ')' { $$ = unary('(', "paren", $2) } /* take '(' as the operator */
| funcall { $$ = $1 }
| expr '+' expr { $$ = binary('+', $1, $2, $3) }
| expr '-' expr { $$ = binary('-', $1, $2, $3) }
| expr '*' expr { $$ = binary('*', $1, $2, $3) }
| expr '/' expr { $$ = binary('/', $1, $2, $3) }
| expr '%' expr { $$ = binary('%', $1, $2, $3) }
| expr '=' expr { $$ = binary('=', $1, $2, $3) }
| expr '<' expr { $$ = binary('<', $1, $2, $3) }
| expr '>' expr { $$ = binary('>', $1, $2, $3) }
| expr LE expr { $$ = binary(LE, $1, $2, $3) }
| expr GE expr { $$ = binary(GE, $1, $2, $3) }
| expr AND expr { $$ = binary(AND, $1, $2, $3) }
| expr OR expr { $$ = binary(OR, $1, $2, $3) }
| NOT expr %prec NOT { $$ = unary(NOT, $1, $2) }
| '-' expr %prec UMINUS { $$ = unary('-', $1, $2) }
;
%%
/* Like Lisp's builtin function cdr. */
func (e *expr) cdr() (r []string) {
for i := 1; i < len(e.sexp); i++ {
r = append(r, e.sexp[i].String())
}
return r
}
func (e *expr) String() string {
if e.typ == 0 { /* a compound expression */
switch e.sexp[0].typ {
case '+', '*', '/', '%', '=', '<', '>', LE, GE, AND, OR:
if len(e.sexp) != 3 {
log.Panicf("Expecting binary expression, got %.10q", e.sexp)
}
return fmt.Sprintf("%s %s %s", e.sexp[1], e.sexp[0].val, e.sexp[2])
case '-':
switch len(e.sexp) {
case 2:
return fmt.Sprintf(" -%s", e.sexp[1])
case 3:
return fmt.Sprintf("%s - %s", e.sexp[1], e.sexp[2])
default:
log.Panicf("Expecting either unary or binary -, got %.10q", e.sexp)
}
case '(':
if len(e.sexp) != 2 {
log.Panicf("Expecting ( ) as unary operator, got %.10q", e.sexp)
}
return fmt.Sprintf("(%s)", e.sexp[1])
case '[':
return "[" + strings.Join(e.cdr(), ", ") + "]"
case NOT:
return fmt.Sprintf("NOT %s", e.sexp[1])
case IDENT: /* function call */
return e.sexp[0].val + "(" + strings.Join(e.cdr(), ", ") + ")"
}
} else {
return fmt.Sprintf("%s", e.val)
}
log.Panicf("Cannot print an unknown expression")
return ""
}
func (s standardSelect) String() string {
r := "SELECT "
if len(s.fields) == 0 {
r += "*"
} else {
r += strings.Join(s.fields, ", ")
}
r += "\nFROM " + strings.Join(s.tables, ", ")
if s.where != nil {
r += fmt.Sprintf("\nWHERE %s", s.where)
}
if len(s.limit) > 0 {
r += fmt.Sprintf("\nLIMIT %s", s.limit)
}
return r + ";"
}
func jsonString(s string) string {
return strings.Replace(
strings.Replace(
strings.Replace(s, "\n", "\\n", -1),
"\r", "\\r", -1),
"\"", "\\\"", -1)
}
func (ats attrs) JSON() string {
ks := []string{}
for k := range ats {
ks = append(ks, k)
}
sort.Strings(ks) /* Remove the randomness of map traversal. */
for i, k := range ks {
ks[i] = fmt.Sprintf(`"%s": "%s"`, k, jsonString(ats[k].String()))
}
return "{\n" + strings.Join(ks, ",\n") + "\n}"
}
func (el exprlist) JSON() string {
ks := []string{}
for _, e := range el {
ks = append(ks, "\"" + jsonString(e.String()) + "\"")
}
return "[\n" + strings.Join(ks, ",\n") + "\n]"
}
func (s trainClause) JSON() string {
fmter := `{
"estimator": "%s",
"attrs": %s,
"columns": %s,
"save": "%s"
}`
return fmt.Sprintf(fmter, s.estimator, s.attrs.JSON(), s.columns.JSON(), s.save)
}
func (s inferClause) JSON() string {
fmter := `{
"model":"%s"
}`
return fmt.Sprintf(fmter, "\"" + s.model + "\"")
}
func (s extendedSelect) JSON() string {
bf := `{
"extended": %t,
"train": %t,
"standardSelect": "%s"
}`
tf := `{
"extended": %t,
"train": %t,
"standardSelect": "%s",
"trainClause": %s
}`
nf := `{
"extended": %t,
"train": %t,
"standardSelect": "%s",
"inferClause": %s
}`
if s.extended {
if s.train {
return fmt.Sprintf(tf, s.extended, s.train,
jsonString(s.standardSelect.String()), s.trainClause.JSON())
} else {
return fmt.Sprintf(nf, s.extended, s.train,
jsonString(s.standardSelect.String()), s.inferClause.JSON())
}
}
return fmt.Sprintf(bf, s.extended, s.train, jsonString(s.standardSelect.String()))
}
func Parse(s string) string {
defer func() {
if e := recover(); e != nil {
log.Fatal(e)
}
}()
sqlParse(newLexer(s))
return parseResult.JSON()
}