das_range Struct Reference

A constraint on one coordinate (or sub-field) used to select matching files. More...

#include <das3/uri.h>

Detailed Description

A constraint on one coordinate (or sub-field) used to select matching files.

An array of das_range structures is passed to the iterator to describe the query. Each entry constrains one named coordinate or sub-field. Template fields whose coordinate is not represented in the array are treated as wildcards.

sCoord format

sCoord names the coordinate or sub-field to constrain:

"time" Whole time coordinate. dBeg and dEnd must be vtTime datums (e.g. from das_datum_fromStr() with an ISO-8601 string). All time sub-fields in the template are filtered against this range.

"time.year" A single time sub-field. dBeg/dEnd must satisfy "time.month" das_vt_isint(datum.vt). Useful when only part of the "time.mday" time coordinate is encoded in the filename. etc.

"sclk.mod64k" A sub-field of a user-registered coordinate type. "sclk.mod60" dBeg/dEnd must satisfy das_vt_isint(datum.vt). etc.

Matching is case-insensitive on the coordinate name portion. The dot separator and sub-field name are case-sensitive.

Datum types

• sCoord == "time" (whole coordinate): datum.vt must be vtTime.
• All other sCoord values: das_vt_isint(datum.vt) must be true. Floating-point coordinates are not supported; decimal points in filenames (before the extension) are essentially unheard of in practice.

Example — query files covering 2025-Oct:

das_range r;
das_range_fromUtc(&r, "2025-10-01", "2025-11-01");

The range is half-open: [dBeg, dEnd). Because a filename may encode only the start of coverage, an extra backward scan is performed to catch files that started before dBeg but whose coverage extends into the query range; the breadth of that scan is governed by the delta= modifier on the template's finest-grained field, or by the natural unit of that field if no delta is specified.

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The documentation for this struct was generated from the following file:

• das3/uri.h