Restructured and make StreamingClap simpler

* Also added a ComptimeClap

1 files changed, 142 insertions, 0 deletions

diff --git a/src/comptime.zig b/src/comptime.zig
new file mode 100644
index 0000000..b11dccc
--- /dev/null
+++ b/src/comptime.zig
@@ -0,0 +1,142 @@
+const clap = @import("index.zig");
+const std = @import("std");
+
+const debug = std.debug;
+const heap = std.heap;
+const mem = std.mem;
+
+pub fn ComptimeClap(comptime Id: type, comptime params: []const clap.Param(Id)) type {
+    var flags: usize = 0;
+    var options: usize = 0;
+    var converted_params: []const clap.Param(usize) = []clap.Param(usize){};
+    for (params) |param| {
+        const index = blk: {
+            if (param.names.long == null and param.names.short == null)
+                break :blk 0;
+            if (param.takes_value) {
+                const res = options;
+                options += 1;
+                break :blk res;
+            }
+
+            const res = flags;
+            flags += 1;
+            break :blk res;
+        };
+
+        converted_params = converted_params ++ []clap.Param(usize){
+            clap.Param(usize).init(index, param.takes_value, param.names),
+        };
+    }
+
+    return struct {
+        options: [options]?[]const u8,
+        flags: [flags]bool,
+        pos: []const []const u8,
+        allocator: *mem.Allocator,
+
+        pub fn parse(allocator: *mem.Allocator, comptime ArgError: type, iter: *clap.args.Iterator(ArgError)) !@This() {
+            var pos = std.ArrayList([]const u8).init(allocator);
+            var res = @This(){
+                .options = []?[]const u8{null} ** options,
+                .flags = []bool{false} ** flags,
+                .pos = undefined,
+                .allocator = allocator,
+            };
+
+            var stream = clap.StreamingClap(usize, ArgError).init(converted_params, iter);
+            while (try stream.next()) |arg| {
+                const param = arg.param;
+                if (param.names.long == null and param.names.short == null) {
+                    try pos.append(arg.value.?);
+                } else if (param.takes_value) {
+                    // We slice before access to avoid false positive access out of bound
+                    // compile error.
+                    res.options[0..][param.id] = arg.value.?;
+                } else {
+                    res.flags[0..][param.id] = true;
+                }
+            }
+
+            res.pos = pos.toOwnedSlice();
+            return res;
+        }
+
+        pub fn deinit(parser: *@This()) void {
+            parser.allocator.free(parser.pos);
+            parser.* = undefined;
+        }
+
+        pub fn flag(parser: @This(), comptime name: []const u8) bool {
+            const param = comptime findParam(name);
+            if (param.takes_value)
+                @compileError(name ++ " is an option and not a flag.");
+
+            return parser.flags[param.id];
+        }
+
+        pub fn option(parser: @This(), comptime name: []const u8) ?[]const u8 {
+            const param = comptime findParam(name);
+            if (!param.takes_value)
+                @compileError(name ++ " is a flag and not an option.");
+
+            return parser.options[param.id];
+        }
+
+        pub fn positionals(parser: @This()) []const []const u8 {
+            return parser.pos;
+        }
+
+        fn findParam(comptime name: []const u8) clap.Param(usize) {
+            comptime {
+                for (converted_params) |param| {
+                    if (param.names.short) |s| {
+                        if (mem.eql(u8, name, "-" ++ []u8{s}))
+                            return param;
+                    }
+                    if (param.names.long) |l| {
+                        if (mem.eql(u8, name, "--" ++ l))
+                            return param;
+                    }
+                }
+
+                @compileError(name ++ " is not a parameter.");
+            }
+        }
+    };
+}
+
+test "clap.comptime.ComptimeClap" {
+    const Clap = ComptimeClap(void, comptime []clap.Param(void){
+        clap.Param(void).init({}, false, clap.Names{
+            .short = 'a',
+            .long = "aa",
+        }),
+        clap.Param(void).init({}, false, clap.Names{
+            .short = 'b',
+            .long = "bb",
+        }),
+        clap.Param(void).init({}, true, clap.Names{
+            .short = 'c',
+            .long = "cc",
+        }),
+        clap.Param(void).init({}, true, clap.Names.positional()),
+    });
+
+    var buf: [1024]u8 = undefined;
+    var fb_allocator = heap.FixedBufferAllocator.init(buf[0..]);
+    var arg_iter = clap.args.SliceIterator.init([][]const u8{
+        "-a", "-c", "0", "something",
+    });
+    var args = try Clap.parse(&fb_allocator.allocator, clap.args.SliceIterator.Error, &arg_iter.iter);
+    defer args.deinit();
+
+    debug.assert(args.flag("-a"));
+    debug.assert(args.flag("--aa"));
+    debug.assert(!args.flag("-b"));
+    debug.assert(!args.flag("--bb"));
+    debug.assert(mem.eql(u8, args.option("-c").?, "0"));
+    debug.assert(mem.eql(u8, args.option("--cc").?, "0"));
+    debug.assert(args.positionals().len == 1);
+    debug.assert(mem.eql(u8, args.positionals()[0], "something"));
+}