Merge lib/stringview

stringview/README.md

@@ -0,0 +1,57 @@
+# stringview
+
+A small, allocation-free library for non-owning views over contiguous byte sequences.
+Supports read-only and mutable views, slicing, substring search, comparison, prefix and suffix checks, ASCII whitespace trimming, and stream output without requiring null-terminated strings.
+
+## Build
+
+From the repository root:
+- release mode: `make stringview`
+- debug mode: `make stringview BUILD=debug`
+- unit tests: `make test-stringview BUILD=debug`
+
+The packaged archive and headers are in `dist/<build>/stringview/`.
+
+## Example
+
+```c
+#include "stringview/stringview.h"
+
+#include <stdio.h>
+
+int main(void) {
+    char text[] = "  hello, world!  ";
+    MutableStringView line = msv_trim(msv_from_cstr(text));
+    size_t separator = msv_find(line, sv_from_cstr(", "));
+
+    if (separator == SV_NPOS) {
+        fputs("separator not found\n", stderr);
+        return 1;
+    }
+
+    MutableStringView greeting = msv_slice(line, 0, separator);
+    MutableStringView subject = msv_substr(line, separator + 2, SIZE_MAX);
+    subject.data[0] = 'W';
+
+    msv_write(stdout, greeting);
+    fputs(", ", stdout);
+    msv_write(stdout, subject);
+    fputc('\n', stdout);
+    return 0;
+}
+```
+
+Save the above code as `example.c` in the repository root and run:
+
+```sh
+cc -std=c23 -Idist/release/stringview/include example.c \
+  dist/release/stringview/lib/libstringview.a -o example
+./example
+```
+
+The program prints `hello, World!`.
+
+> [!IMPORTANT]
+> String views do not own, copy, resize, or free their data.
+> The underlying buffer must remain valid for the lifetime of every view, and mutable views require writable storage.
+> Lengths and indices are measured in bytes, and views are not necessarily null-terminated; use `sv_write` / `msv_write` rather than passing a view directly to APIs that expect a C string.

stringview/include/stringview/stringview.h

@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: Unlicense
+
 /**
  * @file stringview.h
  * @brief Non-owning views over contiguous byte sequences.

stringview/library.mk

@@ -1 +1,3 @@
+# SPDX-License-Identifier: Unlicense
+
 LIB_stringview_DEPS :=

stringview/src/stringview.c

@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: Unlicense
+
 #include <stringview/stringview.h>
 
 #include <stddef.h>

stringview/tests/test_stringview.c

@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: Unlicense
+
 #include "stringview/stringview.h"
 #include "test.h"