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
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
//! The tokenizer.
use super::*;
use peekmore::PeekMoreIterator;
/// A peekable stream of tokens.
#[allow(type_alias_bounds)]
pub type PeekableTokenStream<TS: TokenStream> = PeekMoreIterator<TS>;
/// A stream of tokens.
pub trait TokenStream: Iterator<Item = Token> {}
impl<T> TokenStream for T where T: Iterator<Item = Token> {}
/// Creates an iterator of `Token`'s from the given string slice.
///
/// This does not create `Group`-tokens.
pub fn tokenize(input: &str) -> PeekableTokenStream<impl TokenStream + '_> {
let mut input = PosIter::from(input.char_indices()).peekmore();
let mut encode = [0; std::mem::size_of::<char>() * 2];
std::iter::from_fn(move || {
// Skip any and all whitespace...
let current = loop {
match input.next() {
Some(current) => if current.is_whitespace() {
// keep going
} else {
break current;
},
None => return None
};
};
let index = current.idx;
let mut last_idx = current.idx;
// Turn both the current char and the current with the next char into string slices.
let (currstr, peekstr) = {
let cl0 = current.encode_utf8(&mut encode).len();
let cl1 = input.peek()
.map(|c|c.char)
.unwrap_or(' ')
.encode_utf8(&mut encode[cl0..]).len();
(
std::str::from_utf8(&encode[..(cl0)]).unwrap(),
std::str::from_utf8(&encode[..(cl0+cl1)]).unwrap()
)
};
// Check for symbol pairings...
if let Ok(symbol) = peekstr.parse::<Symbol>() {
input.next(); // drop the paired char
if symbol == Symbol::DoubleDollar {
// Context Reference
return Some((index, index+2, Literal::RefCtx).into());
}
return Some((index, index+2, symbol).into());
}
// Check for individual symbols...
if let Ok(symbol) = currstr.parse::<Symbol>() {
if symbol == Symbol::At { // '@' object references
// TODO: Parse Object Reference (ID)
// (requires integer lexing to be extracted)
if let Some((start, end, uuid)) = try_lex_uuid(&mut input, current.idx) {
return Some((start, end, Literal::ObjUid(uuid)).into());
}
// Parse Object Key Reference
if let Some(PosChar { char, .. }) = input.peek().cloned() {
// Check for start of bareword...
if is_bareword_start(char) {
input.next(); // drop start
let (start, end, bareword)
= try_lex_bareword(&mut input, index, char);
return Some((start, end, Literal::ObjKey(bareword)).into());
}
// Check for start of double-quoted string...
if char == '"' {
input.next(); // drop start
let (start, end, string) = try_lex_string(&mut input, index, char, '"');
return Some((start, end, Literal::ObjKey(string)).into());
}
// Check for start of single-quoted string...
if char == '\'' {
input.next(); // drop start
let (start, end, string) = try_lex_string(&mut input, index, char, '\'');
return Some((start, end, Literal::ObjKey(string)).into());
}
}
panic!("Failed to parse object reference (@) at {}:{}", current.line, current.col);
}
if symbol == Symbol::DollarSign {
// Parse Local Reference
if let Some(PosChar { char, .. }) = input.peek().cloned() {
// Check for start of bareword...
if is_bareword_start(char) {
input.next(); // drop start
let (start, end, bareword)
= try_lex_bareword(&mut input, index, char);
return Some((start, end, Literal::RefVar(bareword)).into());
}
}
// Result Reference
return Some((index, index+1, Literal::RefRes).into());
}
// '+' and '-' are handled elsewhere...
if ! (symbol == Symbol::Plus || symbol == Symbol::Dash) {
// ...everything else is immediately turned into a token.
return Some((index, index+1, symbol).into());
}
}
// Check for start of UUID...
if *current == 'U' {
if let Some((start, end, uuid)) = try_lex_uuid(&mut input, current.idx) {
return Some((start, end, Literal::Uid(uuid)).into());
}
}
// Check for start of bareword...
if is_bareword_start(*current) {
let (start, end, bareword) = try_lex_bareword(&mut input, index, *current);
return Some((start, end,
try_into_constant(bareword.as_str()).unwrap_or(Literal::Str(bareword))
).into());
}
// Check for start of double-quoted string...
if *current == '"' {
let (start, end, string) = try_lex_string(&mut input, index, *current, '"');
return Some((start, end, Literal::Str(string)).into());
}
// Check for start of single-quoted string...
if *current == '\'' {
let (start, end, string) = try_lex_string(&mut input, index, *current, '\'');
return Some((start, end, Literal::Str(string)).into());
}
// NOTE: This is the worst code of this lexer!
// Check for start of number...
if current.is_ascii_digit() || *current == '+' || *current == '-' {
let peeked = input.peek().copied().map(|c|c.char).unwrap_or('0');
let (current, sign, bsign) = match *current {
'-' => {
if !peeked.is_ascii_digit() {
return Some((index, index+1, Symbol::Dash).into());
}
(input.next().map(|c|c.char).unwrap_or('0'), -1.0f64, true)
},
'+' => {
if !peeked.is_ascii_digit() {
return Some((index, index+1, Symbol::Plus).into());
}
(input.next().map(|c|c.char).unwrap_or('0'), 1.0f64, true)
},
_ => (*current, 1.0f64, false)
};
let mut buffer = CompactString::new();
buffer.push(current);
// Check radix.
let mut radix = 10;
if current == '0' {
// Peek the next char and check if it is a RADIX indicator...
radix = match input.peek().copied().map(|c|c.char).unwrap_or(' ') {
// If there is a match, eat it and return a different radix...
'x' => {input.next(); 16},
'd' => {input.next(); 10},
'o' => {input.next(); 8},
'b' => {input.next(); 2},
_ => radix
};
}
// TODO: Break numeric array parsing out into a new function.
if !bsign {
if let Some(PosChar { char: '[', .. }) = input.peek().copied() {
// Array of numbers!
input.next(); // eat [
let mut array: Vec<Token> = vec![]; // TODO: Make this an i64-vec
loop {
if let Some(PosChar { char: ']', idx: index , .. }) = input.peek().copied() {
last_idx = index;
input.next(); // eat ]
break; // end of array
}
buffer.clear();
let mut sign = false;
if let Some(PosChar { char: '-', .. }) = input.peek().copied() {
sign = true;
input.next();
} else if let Some(PosChar { char: '+', .. }) = input.peek().copied() {
sign = false;
input.next();
}
// Eat all the INTEGER digits...
while let Some(PosChar { char: peeked, idx: index , .. }) = input.peek().copied() {
if peeked == ']' { break }
last_idx = index;
if ! is_digit_valid(peeked, radix) {
input.next(); // eat unknown
break
}
buffer.push(peeked);
input.next(); // eat digit
}
if buffer.is_empty() {
continue;
}
let integer = match i64::from_str_radix(&buffer, radix) {
Ok(i) => i,
Err(err) => {
panic!("Failed to parse '{}' with radix {}: {}", buffer, radix, err)
//return Some((index, last_idx, TokenContent::Remainder(buffer.into())).into());
},
};
let integer = sign.then(||-integer).unwrap_or(integer);
array.push((last_idx, last_idx, Literal::Int(integer)).into());
}
return Some((index, last_idx, TokenContent::Group(Symbol::BraketLeft, array)).into());
}
}
// Eat all the INTEGER digits...
while let Some(PosChar { char: peeked, .. }) = input.peek().copied() {
if ! is_digit_valid(peeked, radix) {
break
}
buffer.push(peeked);
input.next(); // eat digit
}
let integer = match i64::from_str_radix(&buffer, radix) {
Ok(i) => i,
Err(err) => panic!("Failed to parse '{}' with radix {}: {}", buffer, radix, err),
};
let decimal = if radix == 10
&& '.' == input.peek_nth(0).copied().map(|c|c.char).unwrap_or(' ')
// This is here so to allow member-access on numbers.
&& input.peek_nth(1).copied().map(|c|c.char).unwrap_or(' ').is_ascii_digit()
// This is here so that two dot's in a row, a range, are not eaten.
&& '.' != input.peek_nth(1).copied().map(|c|c.char).unwrap_or(' ')
{
// Eat all the DECIMALS...
buffer.clear(); // reuse the buffer, cuz why not
buffer.push_str("0.");
input.next(); // eat the `.`
while let Some(PosChar { char: peeked, .. }) = input.peek().copied() {
if peeked.is_ascii_digit() {
buffer.push(peeked);
input.next(); // eat digit
} else {
break;
}
}
buffer.parse().unwrap()
} else {
0f64
};
let pow10: f64 = if radix == 10 && 'e' == input.peek().copied().map(|c|c.char).unwrap_or(' ') {
input.next(); // eat the `e`
let sign = match input.peek().copied().map(|c|c.char).unwrap_or(' ') {
'+' => {input.next(); false}, // eat sign
'-' => {input.next(); true}, // eat sign
_ => false, // dont eat
};
buffer.clear(); // reuse the buffer, cuz why not
while let Some(PosChar { char: peeked , .. }) = input.peek().copied() {
if peeked.is_ascii_digit() {
buffer.push(peeked);
input.next(); // eat digit
} else {
break;
}
}
let mut pow10: i32 = buffer.parse().unwrap();
if sign {pow10 *= -1;}
10f64.powi(pow10)
} else {
1.0
};
if decimal == 0.0 {
if pow10 > 0.0 {
return Some((index, index, Literal::Int((sign as i64) * integer * (pow10 as i64))).into());
}
return Some((index, index, Literal::Dec((sign) * (integer as f64) * (pow10 as f64))).into());
}
let value = (sign) * (integer as f64 + decimal) * (pow10 as f64);
return Some((index, index, Literal::Dec(value)).into());
}
let remainder: String = input.clone().map(|p| p.char).collect();
Some((index, index+remainder.len(), TokenContent::Remainder(remainder)).into())
}).peekmore()
}
fn try_lex_bareword(input: &mut PosInput, start: usize, current: char) -> (usize, usize, CompactString) {
let mut end = start;
let mut buffer = CompactString::new();
buffer.push(current);
while let Some(PosChar { char: peeked, idx: index , .. }) = input.peek().copied() {
end = index;
if is_bareword_part(peeked) {
buffer.push(peeked);
input.next(); // eat char
// NOTE: This could be implemented using `input.next_if`.
} else {
break;
}
}
(start, end, buffer)
}
fn try_lex_string(input: &mut PosInput, start: usize, current: char, delimiter: char) -> (usize, usize, CompactString) {
let mut buffer = CompactString::new();
let mut last = current;
let mut end = start;
#[allow(clippy::while_let_loop)]
loop {
let PosChar { char: peeked, idx: index , .. } = match input.peek().copied() {
Some(i) => i,
None => break // TODO: Return error?
};
end = index;
if peeked == delimiter && last != '\\' {
input.next(); // drop the `"`
break;
} else {
buffer.push(peeked);
input.next(); // eat char
last = peeked;
}
}
(start, end, buffer)
}
/// Try lex uuid.
fn try_lex_uuid(input: &mut PosInput, start: usize) -> Option<(usize, usize, uuid::Uuid)> {
// A uuid is always 36 ascii chars long...
let mut uuid_str: [u8; 36] = [b' '; 36];
// TODO: Make this simpler/safer?
// Try to peek-convert-collect 36 chars into our buffer...
let len = input // Peek
.peek_amount(36)
.iter()
.flatten()
// Convert
.filter_map(|c| std::convert::TryInto::<u8>::try_into(c.char).ok())
// Collect
.enumerate()
.inspect(|(i,c)| uuid_str[*i] = *c)
.count()
;
if let Ok(uuid) = uuid::Uuid::try_parse_ascii(&uuid_str) {
// We must consume the chars we've read!
for _ in 0..len { input.next(); }
return Some((start, start + len, uuid));
}
None
}
/// Attempts to convert a bareword into a constant literal.
fn try_into_constant(str: &str) -> Option<Literal> {
Some(match str {
"null" => Literal::Nil,
"true" => Literal::Bool(true),
"false" => Literal::Bool(false),
"NaN" => Literal::Dec(f64::NAN),
"inf" => Literal::Dec(f64::INFINITY),
"infinity" => Literal::Dec(f64::INFINITY),
"PI" => Literal::Dec(std::f64::consts::PI),
"TAU" => Literal::Dec(std::f64::consts::TAU),
"EULER" => Literal::Dec(std::f64::consts::E),
"SQRT2" => Literal::Dec(std::f64::consts::SQRT_2),
_ => return None
})
}
/// Checks if a given digit is valid under the provided radix.
fn is_digit_valid(peeked: char, radix: u32) -> bool {
match radix {
2 if peeked == '0' || peeked == '1' => true,
8 if ('0'..='7').contains(&peeked) => true,
10 if peeked.is_ascii_digit() => true,
16 if peeked.is_ascii_hexdigit() => true,
_ => false
}
}