57 lines
2.4 KiB
Zig
57 lines
2.4 KiB
Zig
//! Minimal CSV helpers shared by the `/system/configuration/*.csv` config files — the device
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//! registry (`/system/configuration/devices.csv`) and the init service list (`/system/configuration/init.csv`).
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//! Freestanding, no allocator: returned fields are slices into the source line,
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//! so the source must outlive them. `#` starts a comment (whole-line or trailing);
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//! whitespace around a field is trimmed, so columns may be padded for alignment.
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const std = @import("std");
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/// Strip a trailing `#` comment and surrounding whitespace from one raw line.
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/// A blank or comment-only line returns "" (length 0) — the caller's skip signal.
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pub fn stripComment(raw: []const u8) []const u8 {
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const body = if (std.mem.indexOfScalar(u8, raw, '#')) |hash| raw[0..hash] else raw;
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return std.mem.trim(u8, body, " \t\r\n");
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}
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/// Iterate the comma-separated fields of a line body, each trimmed of spaces and
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/// tabs. Build it from a `stripComment`ed body.
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pub const Fields = struct {
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inner: std.mem.SplitIterator(u8, .scalar),
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/// The next field, trimmed, or null when the row is exhausted.
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pub fn next(self: *Fields) ?[]const u8 {
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const field = self.inner.next() orelse return null;
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return std.mem.trim(u8, field, " \t");
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}
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};
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pub fn fields(body: []const u8) Fields {
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return .{ .inner = std.mem.splitScalar(u8, body, ',') };
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}
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// --- tests -------------------------------------------------------------------
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const testing = std.testing;
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test "stripComment trims and drops comments" {
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try testing.expectEqualStrings("a, b", stripComment(" a, b # trailing\r\n"));
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try testing.expectEqualStrings("", stripComment(" # whole-line comment"));
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try testing.expectEqualStrings("", stripComment(" \t "));
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try testing.expectEqualStrings("x", stripComment("x"));
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}
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test "fields splits and trims each column" {
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var it = fields(stripComment("pci, 03 , 80 , /system/drivers/x # note"));
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try testing.expectEqualStrings("pci", it.next().?);
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try testing.expectEqualStrings("03", it.next().?);
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try testing.expectEqualStrings("80", it.next().?);
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try testing.expectEqualStrings("/system/drivers/x", it.next().?);
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try testing.expect(it.next() == null);
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}
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test "a single field yields one column then null" {
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var it = fields(stripComment("/system/services/input"));
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try testing.expectEqualStrings("/system/services/input", it.next().?);
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try testing.expect(it.next() == null);
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}
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