2 releases
| 0.1.1 | Jan 15, 2024 |
|---|---|
| 0.1.0 | Jan 14, 2024 |
#208 in Parser tooling
57KB
1K
SLoC
Fabparse
A parser combinator library in Rust
lib.rs:
Fabparse. A minimized parser combinator library.
Fabparse is a minimized trait based parser combinator library. Most of the
functionality is within the Parser trait. Fabparse implements the parser trait
for a wide variety of types. It restricts itself to a few powerful and composable operations.
All of these are parsers.
| Parser | Input | Parsing | Output | Input after parsing |
|---|---|---|---|---|
'a' |
let mut input = "abc" |
'a'.fab(&mut input) |
'a' |
"bc" |
'a' |
let mut input = "def" |
'a'.fab(&mut input) |
FabError(...) |
"def" |
"abc" |
let mut input = "abcdef" |
"abc".fab(&mut input) |
"abc" |
"def" |
[1, 2] |
let mut input = "[1, 2, 3].as_slice()" |
[1, 2].fab(&mut input) |
[1, 2] |
[3] |
('a'..='z') |
let mut input = "zyx" |
('a'..='z').fab(&mut input) |
z |
"yx" |
take(2) |
let mut input = "abc" |
take(2).fab(&mut input) |
"ab" |
"c" |
❘c❘ c=='m' |
let mut input = "moo" |
(❘c❘ c=='m').fab(&mut input) |
'm' |
"oo" |
char::is_ascii_digit |
let mut input = "123" |
char::is_ascii_digit.fab(&mut input) |
'1' |
"23" |
let parser = ❘c: char❘ if c=='m' {Some(5)} else {None} |
let mut input = "moo" |
parser.fab(&mut input) |
5 |
"oo" |
let parser = ❘c: char❘ if c=='m' {Ok(5)} else {Err(ErrType)} |
let mut input = "moo" |
parser.fab(&mut input) |
5 |
"oo" |
Custom functions can also be parsers.
fn is_it_a(input: &mut &str) -> Result<char, FabError> { 'a'.fab(input) }
| Parser | Input | Parsing | Output | Input after parsing |
|---|---|---|---|---|
is_it_a |
let mut input = "abc" |
is_it_a.fab(&mut input) |
'a' |
"bc" |
These parsers can be modified through the methods available
in the Parser trait.
| Parser | Input | Parsing | Output | Input after parsing |
|---|---|---|---|---|
let parser = 'a'.fab_value(5) |
let mut input = "abc" |
parser.fab(&mut input) |
5 |
"bc" |
let parser = 'a'.fab_map(char::to_ascii_uppercase) |
let mut input = "abc" |
parser.fab(&mut input) |
A |
"bc" |
let parser = '1'.fab_try_map(❘c❘ c.to_digit(10)) |
let mut input = "123" |
parser.fab(&mut input) |
1 |
"23" |
let parser = 'a'.fab_try_map(❘c❘ c.to_digit(10)) |
let mut input = "abc" |
parser.fab(&mut input) |
FabError(...) |
"abc" |
let parser = 'a'.fab_repeat() |
let mut input = "aabb" |
parser.fab(&mut input) |
vec['a','a'] |
"bb" |
let parser = 'a'.fab_repeat() |
let mut input = "bbbb" |
parser.fab(&mut input) |
vec[] |
"bbbb" |
let parser = 'a'.fab_repeat().as_input_slice() |
let mut input = "aabb" |
parser.fab(&mut input) |
"aa" |
"bb" |
let parser = 'a'.fab_repeat().min(1) |
let mut input = "bbbb" |
parser.fab(&mut input) |
FabError(...) |
"bbbb" |
fab_try_map works both with functions that return Results and ones that return Options.
The Repeat struct has additional method for customization trait. These include setting a maximum
number of items to parse, or outputting a custom data structure.
These parsers can be combined with these methods.
| Parser | Input | Parsing | Output | Input after parsing |
|---|---|---|---|---|
alt('a','b') |
let mut input = "abc" |
alt('a','b').fab(&mut input) |
a |
"bc" |
alt('a','b') |
let mut input = "bca" |
alt('a','b').fab(&mut input) |
b |
"ca" |
alt('a','b') |
let mut input = "cab" |
alt('a','b').fab(&mut input) |
FabError(...) |
"cab" |
opt('a') |
let mut input = "abc" |
opt('a').fab(&mut input) |
Some('a') |
"bc" |
opt('a') |
let mut input = "cab" |
opt('a').fab(&mut input) |
None |
"cab" |
take_not('a') |
let mut input = "cab" |
take_not('a').fab(&mut input) |
'c' |
"ab" |
take_not('a') |
let mut input = "abc" |
take_not('a').fab(&mut input) |
FabError(...) |
"abc" |
Some code is inspired by Winnow by Elliot Page + other contributors.
Dependencies
~67KB