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
397
398
399
//! JMESPath runtime with custom functions for expression evaluation.
//!
//! Extends the standard JMESPath runtime with additional functions:
//! - `add(a, b)` - Addition
//! - `subtract(a, b)` - Subtraction
//! - `multiply(a, b)` - Multiplication
//! - `divide(a, b)` - Division (returns null if dividing by zero)
//! - `mod(a, b)` - Modulo (returns null if dividing by zero)
//! - `json_parse(s)` - Parse a JSON string
//! - `is_null(v)` - Check if a value is null
//! - `if(cond, then, else)` - Conditional expression
use std::sync::LazyLock;
/// Global JMESPath runtime instance with custom functions.
pub static JMESPATH_RUNTIME: LazyLock<jmespath::Runtime> =
LazyLock::new(|| {
use jmespath::{
Context, ErrorReason, JmespathError, Rcvar, Runtime, RuntimeError,
Variable,
functions::{ArgumentType, CustomFunction, Signature},
};
use serde_json::Number;
use std::rc::Rc;
// convert arg
fn arg_as_number(
arg: &Rcvar,
ctx: &Context,
position: usize,
) -> Result<f64, JmespathError> {
arg.as_number().ok_or_else(|| {
JmespathError::new(
ctx.expression,
ctx.offset,
ErrorReason::Runtime(RuntimeError::InvalidType {
expected: "number".to_string(),
actual: arg.get_type().to_string(),
position,
}),
)
})
}
#[allow(dead_code)]
fn arg_as_string(
arg: &Rcvar,
ctx: &Context,
position: usize,
) -> Result<String, JmespathError> {
arg.as_string().cloned().ok_or_else(|| {
JmespathError::new(
ctx.expression,
ctx.offset,
ErrorReason::Runtime(RuntimeError::InvalidType {
expected: "string".to_string(),
actual: arg.get_type().to_string(),
position,
}),
)
})
}
#[allow(dead_code)]
fn arg_as_bool(
arg: &Rcvar,
ctx: &Context,
position: usize,
) -> Result<bool, JmespathError> {
arg.as_boolean().ok_or_else(|| {
JmespathError::new(
ctx.expression,
ctx.offset,
ErrorReason::Runtime(RuntimeError::InvalidType {
expected: "boolean".to_string(),
actual: arg.get_type().to_string(),
position,
}),
)
})
}
fn arg_as_array<'var>(
arg: &'var Rcvar,
ctx: &Context,
position: usize,
) -> Result<&'var Vec<Rcvar>, JmespathError> {
arg.as_array().ok_or_else(|| {
JmespathError::new(
ctx.expression,
ctx.offset,
ErrorReason::Runtime(RuntimeError::InvalidType {
expected: "array".to_string(),
actual: arg.get_type().to_string(),
position,
}),
)
})
}
// extract arg
fn any_arg(
args: &[Rcvar],
ctx: &Context,
position: usize,
expect_args_len: usize,
) -> Result<Rcvar, JmespathError> {
args.get(position)
.ok_or_else(|| {
JmespathError::new(
ctx.expression,
ctx.offset,
ErrorReason::Runtime(
RuntimeError::NotEnoughArguments {
expected: expect_args_len,
actual: args.len(),
},
),
)
})
.cloned()
}
fn number_arg(
args: &[Rcvar],
ctx: &Context,
position: usize,
expect_args_len: usize,
) -> Result<f64, JmespathError> {
let arg = any_arg(args, ctx, position, expect_args_len)?;
arg_as_number(&arg, ctx, position)
}
#[allow(dead_code)]
fn nullable_number_arg(
args: &[Rcvar],
ctx: &Context,
position: usize,
expect_args_len: usize,
) -> Result<Option<f64>, JmespathError> {
let arg = any_arg(args, ctx, position, expect_args_len)?;
if arg.is_null() {
Ok(None)
} else {
Ok(Some(arg_as_number(&arg, ctx, position)?))
}
}
#[allow(dead_code)]
fn string_arg(
args: &[Rcvar],
ctx: &Context,
position: usize,
expect_args_len: usize,
) -> Result<String, JmespathError> {
let arg = any_arg(args, ctx, position, expect_args_len)?;
arg_as_string(&arg, ctx, position)
}
#[allow(dead_code)]
fn nullable_string_arg(
args: &[Rcvar],
ctx: &Context,
position: usize,
expect_args_len: usize,
) -> Result<Option<String>, JmespathError> {
let arg = any_arg(args, ctx, position, expect_args_len)?;
if arg.is_null() {
Ok(None)
} else {
Ok(Some(arg_as_string(&arg, ctx, position)?))
}
}
#[allow(dead_code)]
fn bool_arg(
args: &[Rcvar],
ctx: &Context,
position: usize,
expect_args_len: usize,
) -> Result<bool, JmespathError> {
let arg = any_arg(args, ctx, position, expect_args_len)?;
arg_as_bool(&arg, ctx, position)
}
#[allow(dead_code)]
fn nullable_bool_arg(
args: &[Rcvar],
ctx: &Context,
position: usize,
expect_args_len: usize,
) -> Result<Option<bool>, JmespathError> {
let arg = any_arg(args, ctx, position, expect_args_len)?;
if arg.is_null() {
Ok(None)
} else {
Ok(Some(arg_as_bool(&arg, ctx, position)?))
}
}
#[allow(dead_code)]
fn array_arg(
args: &[Rcvar],
ctx: &Context,
position: usize,
expect_args_len: usize,
) -> Result<Vec<Rcvar>, JmespathError> {
let arg = any_arg(args, ctx, position, expect_args_len)?;
let array = arg_as_array(&arg, ctx, position)?;
Ok(array.clone())
}
fn number_array_arg(
args: &[Rcvar],
ctx: &Context,
position: usize,
expect_args_len: usize,
) -> Result<Vec<f64>, JmespathError> {
let arg = any_arg(args, ctx, position, expect_args_len)?;
let array = arg_as_array(&arg, ctx, position)?;
let mut numbers = Vec::with_capacity(array.len());
for item in array.iter() {
let number = arg_as_number(item, ctx, position)?;
numbers.push(number);
}
Ok(numbers)
}
// return value
fn rcvar_f64(n: f64) -> Rcvar {
Rc::new(Variable::Number(
Number::from_f64(n).unwrap_or(Number::from_f64(0.0).unwrap()),
))
}
#[allow(dead_code)]
fn rcvar_f64_u64(n: f64) -> Rcvar {
Rc::new(Variable::Number(Number::from(n.round() as u64)))
}
let mut runtime = Runtime::new();
// https://jmespath.org/specification.html
runtime.register_builtin_functions();
// basic math
runtime.register_function(
"add",
Box::new(CustomFunction::new(
Signature::new(
vec![ArgumentType::Number, ArgumentType::Number],
None,
),
Box::new(|args: &[Rcvar], ctx: &mut Context| {
let a = number_arg(args, ctx, 0, 2)?;
let b = number_arg(args, ctx, 1, 2)?;
Ok(rcvar_f64(a + b))
}),
)),
);
runtime.register_function(
"subtract",
Box::new(CustomFunction::new(
Signature::new(
vec![ArgumentType::Number, ArgumentType::Number],
None,
),
Box::new(|args: &[Rcvar], ctx: &mut Context| {
let a = number_arg(args, ctx, 0, 2)?;
let b = number_arg(args, ctx, 1, 2)?;
Ok(rcvar_f64(a - b))
}),
)),
);
runtime.register_function(
"multiply",
Box::new(CustomFunction::new(
Signature::new(
vec![ArgumentType::Number, ArgumentType::Number],
None,
),
Box::new(|args: &[Rcvar], ctx: &mut Context| {
let a = number_arg(args, ctx, 0, 2)?;
let b = number_arg(args, ctx, 1, 2)?;
Ok(rcvar_f64(a * b))
}),
)),
);
runtime.register_function(
"divide",
Box::new(CustomFunction::new(
Signature::new(
vec![ArgumentType::Number, ArgumentType::Number],
None,
),
Box::new(|args: &[Rcvar], ctx: &mut Context| {
let a = number_arg(args, ctx, 0, 2)?;
let b = number_arg(args, ctx, 1, 2)?;
if b == 0.0 {
Ok(Rc::new(Variable::Null))
} else {
Ok(rcvar_f64(a / b))
}
}),
)),
);
runtime.register_function(
"mod",
Box::new(CustomFunction::new(
Signature::new(
vec![ArgumentType::Number, ArgumentType::Number],
None,
),
Box::new(|args: &[Rcvar], ctx: &mut Context| {
let a = number_arg(args, ctx, 0, 2)?;
let b = number_arg(args, ctx, 1, 2)?;
if b == 0.0 {
Ok(Rc::new(Variable::Null))
} else {
Ok(rcvar_f64(a % b))
}
}),
)),
);
// zips a 2D array and maps each column with an expref
// if sub-arrays are of different lengths, fills missing values with null
runtime.register_function(
"zip_map",
Box::new(CustomFunction::new(
Signature::new(
vec![
ArgumentType::Expref,
ArgumentType::TypedArray(Box::new(ArgumentType::Array)),
],
None,
),
Box::new(|args: &[Rcvar], ctx: &mut Context| {
let expref = args[0].as_expref().unwrap();
let input_array = args[1].as_array().unwrap();
let mut output_array = Vec::with_capacity(
input_array
.iter()
.map(|v| v.as_array().unwrap().len())
.max()
.unwrap_or_default(),
);
for i in 0..output_array.capacity() {
let mut column = Vec::with_capacity(input_array.len());
for row in input_array.iter() {
let row_array = row.as_array().unwrap();
if let Some(value) = row_array.get(i) {
column.push(value.clone());
} else {
column.push(Rc::new(Variable::Null));
}
}
output_array.push(jmespath::interpret(
&Rc::new(Variable::Array(column)),
&expref,
ctx,
)?);
}
Ok(Rc::new(Variable::Array(output_array)))
}),
)),
);
// L1 normalization of a number array
runtime.register_function(
"l1_normalize",
Box::new(CustomFunction::new(
Signature::new(
vec![ArgumentType::TypedArray(Box::new(
ArgumentType::Number,
))],
None,
),
Box::new(|args: &[Rcvar], ctx: &mut Context| {
let numbers = number_array_arg(args, ctx, 0, 1)?;
let sum: f64 = numbers.iter().map(|n| n.abs()).sum();
if numbers.len() == 0 {
Ok(Rc::new(Variable::Array(Vec::new())))
} else if sum == 0.0 {
Ok(Rc::new(Variable::Array(
numbers
.iter()
.map(|_| {
Rc::new(Variable::Number(
Number::from_f64(
1.0 / numbers.len() as f64,
)
.unwrap(),
))
})
.collect(),
)))
} else {
Ok(Rc::new(Variable::Array(
numbers
.iter()
.map(|n| rcvar_f64(n / sum))
.collect(),
)))
}
}),
)),
);
runtime
});