From c034b4a1291a803028eef8b0950a7090ea54b047 Mon Sep 17 00:00:00 2001 From: Nic Gaffney Date: Tue, 21 Oct 2025 00:09:07 -0500 Subject: Currying, Combinators, and organization --- src/lib.zig | 107 +++--------------------------------------------------------- 1 file changed, 5 insertions(+), 102 deletions(-) (limited to 'src/lib.zig') diff --git a/src/lib.zig b/src/lib.zig index 0a50a80..721b2a0 100644 --- a/src/lib.zig +++ b/src/lib.zig @@ -1,102 +1,5 @@ -const std = @import("std"); -const Type = std.builtin.Type; - -fn typeVerify(T: type, expected: anytype) Type { - const expectedType = @TypeOf(expected); - const expectedTypeInfo = @typeInfo(expectedType); - if (expectedTypeInfo != .@"struct") - @compileError("Expected struct or tuple, found " ++ @typeName(expectedType)); - const realTypeInfo = @typeInfo(T); - for (expected) |e| { - if(realTypeInfo == e) return realTypeInfo; - } - for (expected) |e| - @compileError("Expected one of " ++ @tagName(e) ++ ", found " ++ @typeName(T)); - return realTypeInfo; -} - -/// ```zig -/// (fn (fn (b) c, fn (a) b) fn (a) c) -/// ``` -/// Function composition -/// Type signature: (a -> b) -> (b -> c) -> (a -> c) -/// `outerFunc` and `innerFunc` are functions of types `b -> c` and `a -> b` respectively -/// Haskell equivalent: `outerFunc . innerFunc` -pub fn compose( - comptime outerFunc: anytype, - comptime innerFunc: anytype -) blk:{ - _=typeVerify(@TypeOf(outerFunc), .{ .@"fn" }); - _=typeVerify(@TypeOf(innerFunc), .{ .@"fn" }); - const out = @typeInfo(@TypeOf(outerFunc)).@"fn".return_type.?; - const in = @typeInfo(@TypeOf(innerFunc)).@"fn".params[0].type.?; - break :blk fn(in) out; -} { - const out = @typeInfo(@TypeOf(outerFunc)).@"fn".return_type.?; - const in = @typeInfo(@TypeOf(innerFunc)).@"fn".params[0].type.?; - return struct { - fn func(input: in) out { - return outerFunc(innerFunc(input)); - } - }.func; -} - -/// ```zig -/// (fn (Allocator, fn (fn (a) b, []a) error{OutOfMemory}![]b) -/// ``` -/// Map a function onto a list of values, allocating space for the new slice -/// Type signature: `(a -> b) -> [a] -> [b]` -/// `func` is of type `a -> b`, where `items` is of type `[a]`. -/// `map` will return a slice of type `[b]` -/// Haskell equivalent: `map func items` -pub fn mapAlloc( - allocator: std.mem.Allocator, - func: anytype, - items: anytype, -) error{OutOfMemory}!blk:{ - const funcInfo = typeVerify(@TypeOf(func), .{ .@"fn" }); - const itemsInfo = typeVerify(@TypeOf(items), .{ .array, .pointer }); - switch (itemsInfo) { - .pointer => |p| if(p.size != .many and p.size != .slice) - @compileError("Expected pointer of size 'many' or 'slice', found " ++ @tagName(p)), - else =>{}, - } - - break :blk []funcInfo.@"fn".return_type.?; -} { - const funcInfo = typeVerify(@TypeOf(func), .{ .@"fn" }); - var result = try allocator.alloc(funcInfo.@"fn".return_type.?, items.len); - for(items, 0..) |item, i| - result[i] = func(item); - return result; -} - -/// ```zig -/// (fn (Allocator, fn (fn (a) b, []a, *[]b) void) -/// ``` -/// Map a function onto a list of values, using a buffer -/// Type signature: `(a -> b) -> [a] -> [b]` -/// `func` is of type `a -> b`, where `items` is of type `[a]` and `buffer` is a pointer to a value of type `[b]`. -/// Haskell equivalent: `map func items` -pub fn map( - func: anytype, - items: anytype, - buffer: anytype, -) void { - _=typeVerify(@TypeOf(func), .{ .@"fn" }); - const itemsInfo = typeVerify(@TypeOf(items), .{ .pointer, .array }); - const bufferInfo = typeVerify(@TypeOf(buffer), .{ .pointer }); - const bufferChildInfo = typeVerify(bufferInfo.pointer.child, .{ .pointer, .array }); - switch (itemsInfo) { - .pointer => |p| if(p.size != .many and p.size != .slice) - @compileError("Expected pointer of size 'many' or 'slice', found '" ++ @tagName(p.size) ++ "'"), - else =>{}, - } - switch (bufferChildInfo) { - .pointer => |p| if(p.size != .many and p.size != .slice) - @compileError("Expected pointer of size 'many' or 'slice', found '" ++ @tagName(p.size) ++ "'"), - else =>{}, - } - for (items, 0..) |item, i| - buffer.*[i] = func(item); -} +pub const map = @import("map.zig").map; +pub const mapAlloc = @import("map.zig").mapAlloc; +pub const curry = @import("curry.zig").curry; +pub const compose = @import("compose.zig").compose; +pub const combinators = @import("combinators.zig"); -- cgit v1.2.3