1 unstable release
0.1.0 | Jan 26, 2019 |
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#135 in #codegen
10KB
180 lines
csv2struct
Generates struct definitions from CSV using some very basic rules.
Example
$ cat test.csv
foo,bar,baz,qux
1,2,3,green
4.4,5,6,red
7.2,,8,blue
$ cat test.csv | csv2struct
#[derive(Debug, Clone, Copy, Eq)]
pub struct Record {
pub foo: f32,
pub bar: Option<i32>,
pub baz: i32,
pub qux: Qux,
}
#[derive(Debug, Clone, Copy, Eq)]
pub enum Qux {
Green,
Red,
Blue,
}
There are two sets of rules at play. First, we apply the following set of rules to each value in each column and record the results.
if value == "" => Empty
if let Some(_) = value.parse::<i32>() => Integer
if let Some(_) = value.parse::<f32>() => Real
else => Factor(value)
Next, we apply the following rules to the results for each column:
- If any of the values were parsed as Factor; then treat the column as a factor.
- Otherwise, if not all of the values were parsed as Integer; then treat the column as real.
- Otherwise, treat the column as integer.
- If any of the values were missing, then apply the above rules to the values
that were present, and wrap the result in
Option
.
Finally, we generate a struct definition with one field for each column. For factors, we generate an enum as well.
Dependencies
~2MB
~23K SLoC