From 3f62410c524fd647c083f7225251e3b09808c6bb Mon Sep 17 00:00:00 2001
From: George Abbott <george@gabbott.dev>
Date: Sun, 26 Jan 2025 11:37:33 +0000
Subject: strbuilder
---
scripts/strbuilder/build.zig | 91 +++++++++++++++++++++++++++++++
scripts/strbuilder/build.zig.zon | 72 +++++++++++++++++++++++++
scripts/strbuilder/src/main.zig | 24 +++++++++
scripts/strbuilder/src/root.zig | 113 +++++++++++++++++++++++++++++++++++++++
4 files changed, 300 insertions(+)
create mode 100644 scripts/strbuilder/build.zig
create mode 100644 scripts/strbuilder/build.zig.zon
create mode 100644 scripts/strbuilder/src/main.zig
create mode 100644 scripts/strbuilder/src/root.zig
diff --git a/scripts/strbuilder/build.zig b/scripts/strbuilder/build.zig
new file mode 100644
index 0000000..c8a0c23
--- /dev/null
+++ b/scripts/strbuilder/build.zig
@@ -0,0 +1,91 @@
+const std = @import("std");
+
+// Although this function looks imperative, note that its job is to
+// declaratively construct a build graph that will be executed by an external
+// runner.
+pub fn build(b: *std.Build) void {
+ // Standard target options allows the person running `zig build` to choose
+ // what target to build for. Here we do not override the defaults, which
+ // means any target is allowed, and the default is native. Other options
+ // for restricting supported target set are available.
+ const target = b.standardTargetOptions(.{});
+
+ // Standard optimization options allow the person running `zig build` to select
+ // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
+ // set a preferred release mode, allowing the user to decide how to optimize.
+ const optimize = b.standardOptimizeOption(.{});
+
+ const lib = b.addStaticLibrary(.{
+ .name = "strbuilder",
+ // In this case the main source file is merely a path, however, in more
+ // complicated build scripts, this could be a generated file.
+ .root_source_file = b.path("src/root.zig"),
+ .target = target,
+ .optimize = optimize,
+ });
+
+ // This declares intent for the library to be installed into the standard
+ // location when the user invokes the "install" step (the default step when
+ // running `zig build`).
+ b.installArtifact(lib);
+
+ const exe = b.addExecutable(.{
+ .name = "strbuilder",
+ .root_source_file = b.path("src/main.zig"),
+ .target = target,
+ .optimize = optimize,
+ });
+
+ // This declares intent for the executable to be installed into the
+ // standard location when the user invokes the "install" step (the default
+ // step when running `zig build`).
+ b.installArtifact(exe);
+
+ // This *creates* a Run step in the build graph, to be executed when another
+ // step is evaluated that depends on it. The next line below will establish
+ // such a dependency.
+ const run_cmd = b.addRunArtifact(exe);
+
+ // By making the run step depend on the install step, it will be run from the
+ // installation directory rather than directly from within the cache directory.
+ // This is not necessary, however, if the application depends on other installed
+ // files, this ensures they will be present and in the expected location.
+ run_cmd.step.dependOn(b.getInstallStep());
+
+ // This allows the user to pass arguments to the application in the build
+ // command itself, like this: `zig build run -- arg1 arg2 etc`
+ if (b.args) |args| {
+ run_cmd.addArgs(args);
+ }
+
+ // This creates a build step. It will be visible in the `zig build --help` menu,
+ // and can be selected like this: `zig build run`
+ // This will evaluate the `run` step rather than the default, which is "install".
+ const run_step = b.step("run", "Run the app");
+ run_step.dependOn(&run_cmd.step);
+
+ // Creates a step for unit testing. This only builds the test executable
+ // but does not run it.
+ const lib_unit_tests = b.addTest(.{
+ .root_source_file = b.path("src/root.zig"),
+ .target = target,
+ .optimize = optimize,
+ });
+
+ const run_lib_unit_tests = b.addRunArtifact(lib_unit_tests);
+
+ const exe_unit_tests = b.addTest(.{
+ .root_source_file = b.path("src/main.zig"),
+ .target = target,
+ .optimize = optimize,
+ });
+
+ const run_exe_unit_tests = b.addRunArtifact(exe_unit_tests);
+
+ // Similar to creating the run step earlier, this exposes a `test` step to
+ // the `zig build --help` menu, providing a way for the user to request
+ // running the unit tests.
+ const test_step = b.step("test", "Run unit tests");
+ test_step.dependOn(&run_lib_unit_tests.step);
+ test_step.dependOn(&run_exe_unit_tests.step);
+}
diff --git a/scripts/strbuilder/build.zig.zon b/scripts/strbuilder/build.zig.zon
new file mode 100644
index 0000000..3ce0186
--- /dev/null
+++ b/scripts/strbuilder/build.zig.zon
@@ -0,0 +1,72 @@
+.{
+ // This is the default name used by packages depending on this one. For
+ // example, when a user runs `zig fetch --save <url>`, this field is used
+ // as the key in the `dependencies` table. Although the user can choose a
+ // different name, most users will stick with this provided value.
+ //
+ // It is redundant to include "zig" in this name because it is already
+ // within the Zig package namespace.
+ .name = "strbuilder",
+
+ // This is a [Semantic Version](https://semver.org/).
+ // In a future version of Zig it will be used for package deduplication.
+ .version = "0.0.0",
+
+ // This field is optional.
+ // This is currently advisory only; Zig does not yet do anything
+ // with this value.
+ //.minimum_zig_version = "0.11.0",
+
+ // This field is optional.
+ // Each dependency must either provide a `url` and `hash`, or a `path`.
+ // `zig build --fetch` can be used to fetch all dependencies of a package, recursively.
+ // Once all dependencies are fetched, `zig build` no longer requires
+ // internet connectivity.
+ .dependencies = .{
+ // See `zig fetch --save <url>` for a command-line interface for adding dependencies.
+ //.example = .{
+ // // When updating this field to a new URL, be sure to delete the corresponding
+ // // `hash`, otherwise you are communicating that you expect to find the old hash at
+ // // the new URL.
+ // .url = "https://example.com/foo.tar.gz",
+ //
+ // // This is computed from the file contents of the directory of files that is
+ // // obtained after fetching `url` and applying the inclusion rules given by
+ // // `paths`.
+ // //
+ // // This field is the source of truth; packages do not come from a `url`; they
+ // // come from a `hash`. `url` is just one of many possible mirrors for how to
+ // // obtain a package matching this `hash`.
+ // //
+ // // Uses the [multihash](https://multiformats.io/multihash/) format.
+ // .hash = "...",
+ //
+ // // When this is provided, the package is found in a directory relative to the
+ // // build root. In this case the package's hash is irrelevant and therefore not
+ // // computed. This field and `url` are mutually exclusive.
+ // .path = "foo",
+
+ // // When this is set to `true`, a package is declared to be lazily
+ // // fetched. This makes the dependency only get fetched if it is
+ // // actually used.
+ // .lazy = false,
+ //},
+ },
+
+ // Specifies the set of files and directories that are included in this package.
+ // Only files and directories listed here are included in the `hash` that
+ // is computed for this package. Only files listed here will remain on disk
+ // when using the zig package manager. As a rule of thumb, one should list
+ // files required for compilation plus any license(s).
+ // Paths are relative to the build root. Use the empty string (`""`) to refer to
+ // the build root itself.
+ // A directory listed here means that all files within, recursively, are included.
+ .paths = .{
+ "build.zig",
+ "build.zig.zon",
+ "src",
+ // For example...
+ //"LICENSE",
+ //"README.md",
+ },
+}
diff --git a/scripts/strbuilder/src/main.zig b/scripts/strbuilder/src/main.zig
new file mode 100644
index 0000000..c8a3f67
--- /dev/null
+++ b/scripts/strbuilder/src/main.zig
@@ -0,0 +1,24 @@
+const std = @import("std");
+
+pub fn main() !void {
+ // Prints to stderr (it's a shortcut based on `std.io.getStdErr()`)
+ std.debug.print("All your {s} are belong to us.\n", .{"codebase"});
+
+ // stdout is for the actual output of your application, for example if you
+ // are implementing gzip, then only the compressed bytes should be sent to
+ // stdout, not any debugging messages.
+ const stdout_file = std.io.getStdOut().writer();
+ var bw = std.io.bufferedWriter(stdout_file);
+ const stdout = bw.writer();
+
+ try stdout.print("Run `zig build test` to run the tests.\n", .{});
+
+ try bw.flush(); // don't forget to flush!
+}
+
+test "simple test" {
+ var list = std.ArrayList(i32).init(std.testing.allocator);
+ defer list.deinit(); // try commenting this out and see if zig detects the memory leak!
+ try list.append(42);
+ try std.testing.expectEqual(@as(i32, 42), list.pop());
+}
diff --git a/scripts/strbuilder/src/root.zig b/scripts/strbuilder/src/root.zig
new file mode 100644
index 0000000..bcaf445
--- /dev/null
+++ b/scripts/strbuilder/src/root.zig
@@ -0,0 +1,113 @@
+const std = @import("std");
+const testing = std.testing;
+const Allocator = std.heap.Allocator;
+const ArrayList = std.ArrayList;
+
+// Considerations
+// When doing replaces, each replace may need to factor in previous replaces, deletes, etc.
+// E.g. the text "Hi (Deletedah) ahThere" will be -2 bytes with replace("ah", "") after the
+// deletion has occurred, but if naively written, then -4 bytes will be calculated for.
+
+const OpTag = enum {
+ append,
+ prepend,
+ insert,
+ replace_all,
+};
+
+const Op = union(OpTag) {
+ append: struct { s: []const u8 },
+ prepend: struct { s: []const u8 },
+ insert: struct { pos: usize, s: []const u8 },
+ replace_all: struct { old: []const u8, new: []const u8, additional_bytes_to_allocate: isize },
+};
+
+// TODO
+export const StrBuilder = struct {
+ allocator: Allocator,
+ ops: ArrayList(Op),
+ base: []const u8,
+
+ pub fn new(allocator: Allocator, base: []const u8) StrBuilder {
+ var ret = StrBuilder{};
+ ret.allocator = allocator;
+ ret.ops = ArrayList(Op).init(allocator);
+ ret.base = base;
+
+ return ret;
+ }
+
+ pub fn build(self: StrBuilder) []const u8 {
+ // TODO
+ }
+
+ pub fn deinit(self: StrBuilder) void {
+ self.ops.deinit();
+ }
+
+ pub fn append(self: StrBuilder, s: []const u8) void {
+ self.ops.append(Op{ .append = .{ .s = s } });
+ }
+ pub fn prepend(self: StrBuilder, s: []const u8) void {
+ self.ops.append(Op{ .prepend = .{ .s = s } });
+ }
+ pub fn insert(self: StrBuilder, pos: usize, s: []const u8) void {
+ self.ops.append(Op{ .insert = .{ .pos = pos, .s = s } });
+ }
+ pub fn replaceAll(self: StrBuilder, old_str: []const u8, new_str: []const u8) void {
+ // TODO: find count of `old` and store the additional allocatable size in the enum(union).
+ // Signed (isize) so as to allow the case when old.len > new.len.
+ const additional_bytes_req: isize = std.mem.count(u8, self.base, self.old) * (new.len - old.len);
+ self.ops.append(Op{ .replace_all = .{ .old = old_str, .new = new_str, .additional_bytes_to_allocate = additional_bytes_req } });
+ }
+ /// If the line matches the given predicate, delete the line.
+ pub fn deleteLineIf(self: StrBuilder, pred: fn (line: []const u8) bool) void {
+ // TODO
+ }
+
+ /// Replaces a prefix in all lines if the line begins with said prefix.
+ pub fn replacePrefixLinewise(self: StrBuilder, old_prefix: []const u8, new_prefix: []const u8) void {
+ // TODO
+ }
+
+ // Used for replacing text of the form: P*I*S where P is a common prefix, I
+ // an infix, and S a suffix. Any text can occur in * (though consider opts).
+ // Useful, e.g. to turn @@[text][href] into <a href="href">text</a>.
+ pub const ReplaceBipartOpts = struct {
+ allowNewline: bool,
+ };
+ pub fn replaceBipart(
+ self: StrBuilder,
+ p: []const u8,
+ i: []const u8,
+ s: []const u8,
+ new_p: []const u8,
+ new_i: []const u8,
+ new_s: []const u8,
+ opts: ReplaceBipartOpts,
+ ) void {
+ // TODO
+ }
+
+ pub fn calculateSizeToAllocate(self: StrBuilder) usize {
+ var diff: isize = 0;
+ for (self.ops.items) |op| {
+ switch (op) {
+ OpTag.append, OpTag.prepend => |s| {
+ diff += s.len;
+ },
+ OpTag.insert => |c| {
+ diff += c.s.len;
+ },
+ OpTag.replace_all => |c| {
+ diff += c.additional_bytes_to_allocate;
+ },
+ }
+ }
+ return self.base.len + diff;
+ }
+};
+
+test "basic add functionality" {
+ try testing.expect(add(3, 7) == 10);
+}
--
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