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reifydb_function/text/
char.rs

1// SPDX-License-Identifier: AGPL-3.0-or-later
2// Copyright (c) 2025 ReifyDB
3
4use reifydb_core::value::column::data::ColumnData;
5use reifydb_type::value::{constraint::bytes::MaxBytes, container::utf8::Utf8Container, r#type::Type};
6
7use crate::{
8	ScalarFunction, ScalarFunctionContext,
9	error::{ScalarFunctionError, ScalarFunctionResult},
10	propagate_options,
11};
12
13pub struct TextChar;
14
15impl TextChar {
16	pub fn new() -> Self {
17		Self
18	}
19}
20
21impl ScalarFunction for TextChar {
22	fn scalar(&self, ctx: ScalarFunctionContext) -> ScalarFunctionResult<ColumnData> {
23		if let Some(result) = propagate_options(self, &ctx) {
24			return result;
25		}
26
27		let columns = ctx.columns;
28		let row_count = ctx.row_count;
29
30		if columns.len() != 1 {
31			return Err(ScalarFunctionError::ArityMismatch {
32				function: ctx.fragment.clone(),
33				expected: 1,
34				actual: columns.len(),
35			});
36		}
37
38		let col = columns.get(0).unwrap();
39
40		match col.data() {
41			ColumnData::Int1(c) => {
42				convert_to_char(row_count, c.data().len(), |i| c.get(i).map(|&v| v as u32))
43			}
44			ColumnData::Int2(c) => {
45				convert_to_char(row_count, c.data().len(), |i| c.get(i).map(|&v| v as u32))
46			}
47			ColumnData::Int4(c) => {
48				convert_to_char(row_count, c.data().len(), |i| c.get(i).map(|&v| v as u32))
49			}
50			ColumnData::Int8(c) => {
51				convert_to_char(row_count, c.data().len(), |i| c.get(i).map(|&v| v as u32))
52			}
53			ColumnData::Uint1(c) => {
54				convert_to_char(row_count, c.data().len(), |i| c.get(i).map(|&v| v as u32))
55			}
56			ColumnData::Uint2(c) => {
57				convert_to_char(row_count, c.data().len(), |i| c.get(i).map(|&v| v as u32))
58			}
59			ColumnData::Uint4(c) => {
60				convert_to_char(row_count, c.data().len(), |i| c.get(i).map(|&v| v as u32))
61			}
62			other => Err(ScalarFunctionError::InvalidArgumentType {
63				function: ctx.fragment.clone(),
64				argument_index: 0,
65				expected: vec![Type::Int1, Type::Int2, Type::Int4, Type::Int8],
66				actual: other.get_type(),
67			}),
68		}
69	}
70
71	fn return_type(&self, _input_types: &[Type]) -> Type {
72		Type::Utf8
73	}
74}
75
76fn convert_to_char<F>(row_count: usize, _capacity: usize, get_value: F) -> ScalarFunctionResult<ColumnData>
77where
78	F: Fn(usize) -> Option<u32>,
79{
80	let mut result_data = Vec::with_capacity(row_count);
81
82	for i in 0..row_count {
83		match get_value(i) {
84			Some(code_point) => {
85				if let Some(ch) = char::from_u32(code_point) {
86					result_data.push(ch.to_string());
87				} else {
88					result_data.push(String::new());
89				}
90			}
91			None => {
92				result_data.push(String::new());
93			}
94		}
95	}
96
97	Ok(ColumnData::Utf8 {
98		container: Utf8Container::new(result_data),
99		max_bytes: MaxBytes::MAX,
100	})
101}