Merge branch 'docs-type-aliases' of github.com:rtfeldman/roc into docs-type-aliases

BUILDING_FROM_SOURCE.md

@@ -23,6 +23,22 @@ For debugging LLVM IR, we use [DebugIR](https://github.com/vaivaswatha/debugir).
 MacOS systems should already have `libunwind`, but other systems will need to install it (On Ubuntu, this can be donw with `sudo apt-get install libunwind-dev`).
 Some systems may already have `libc++-dev` on them, but if not, you may need to install it. (On Ubuntu, this can be done with `sudo apt-get install libc++-dev`.)
 
+### libcxb libraries
+
+You may see an error like this during builds:
+
+```
+/usr/bin/ld: cannot find -lxcb-render
+/usr/bin/ld: cannot find -lxcb-shape
+/usr/bin/ld: cannot find -lxcb-xfixes
+```
+
+If so, you can fix it like so:
+
+```
+sudo apt-get install libxcb-render0-dev libxcb-shape0-dev libxcb-xfixes0-dev
+```
+
 ### Zig
 **version: 0.7.x**
 

compiler/builtins/bitcode/src/list.zig

@@ -7,6 +7,7 @@ const Allocator = mem.Allocator;
 const TAG_WIDTH = 8;
 
 const EqFn = fn (?[*]u8, ?[*]u8) callconv(.C) bool;
+const CompareFn = fn (?[*]u8, ?[*]u8, ?[*]u8) callconv(.C) u8;
 const Opaque = ?[*]u8;
 
 const Inc = fn (?[*]u8) callconv(.C) void;
@@ -118,6 +119,59 @@ const Caller1 = fn (?[*]u8, ?[*]u8, ?[*]u8) callconv(.C) void;
 const Caller2 = fn (?[*]u8, ?[*]u8, ?[*]u8, ?[*]u8) callconv(.C) void;
 const Caller3 = fn (?[*]u8, ?[*]u8, ?[*]u8, ?[*]u8, ?[*]u8) callconv(.C) void;
 
+pub fn listReverse(list: RocList, alignment: usize, element_width: usize) callconv(.C) RocList {
+    if (list.bytes) |source_ptr| {
+        const size = list.len();
+
+        var i: usize = 0;
+        var end: usize = size - 1;
+
+        if (list.isUnique()) {
+            const temp: [*]u8 = @ptrCast([*]u8, std.heap.c_allocator.alloc(u8, element_width) catch unreachable);
+
+            // Working from the front and back so
+            // we only need to go ~(n / 2) iterations.
+            // If the length is an odd number the middle
+            // element stays in the same place anyways.
+            while (i < (end - i)) : (i += 1) {
+                const last_position = end - i;
+
+                const last_element = source_ptr + (last_position * element_width);
+                const first_element = source_ptr + (i * element_width);
+
+                // Store Last Element in temp
+                @memcpy(temp, last_element, element_width);
+
+                // Swap Last Element with First Element
+                @memcpy(last_element, first_element, element_width);
+
+                // Swap First Element with temp
+                @memcpy(first_element, temp, element_width);
+            }
+
+            std.heap.c_allocator.free(temp[0..element_width]);
+
+            return list;
+        } else {
+            const output = RocList.allocate(std.heap.c_allocator, alignment, size, element_width);
+
+            const target_ptr = output.bytes orelse unreachable;
+
+            while (i < size) : (i += 1) {
+                const last_position = end - i;
+
+                @memcpy(target_ptr + (i * element_width), source_ptr + (last_position * element_width), element_width);
+            }
+
+            utils.decref(std.heap.c_allocator, alignment, list.bytes, size * element_width);
+
+            return output;
+        }
+    } else {
+        return RocList.empty();
+    }
+}
+
 pub fn listMap(list: RocList, transform: Opaque, caller: Caller1, alignment: usize, old_element_width: usize, new_element_width: usize) callconv(.C) RocList {
     if (list.bytes) |source_ptr| {
         const size = list.len();
@@ -688,3 +742,81 @@ fn listRangeHelp(allocator: *Allocator, comptime T: type, low: T, high: T) RocLi
         },
     }
 }
+
+inline fn swapHelp(width: usize, temporary: [*]u8, ptr1: [*]u8, ptr2: [*]u8) void {
+    @memcpy(temporary, ptr1, width);
+    @memcpy(ptr1, ptr2, width);
+    @memcpy(ptr2, temporary, width);
+}
+
+fn swap(source_ptr: [*]u8, element_width_initial: usize, index_1: usize, index_2: usize) void {
+    const threshold: comptime usize = 64;
+
+    var element_width = element_width_initial;
+
+    var buffer_actual: [threshold]u8 = undefined;
+    var buffer: [*]u8 = buffer_actual[0..];
+
+    var element_at_i = source_ptr + (index_1 * element_width);
+    var element_at_j = source_ptr + (index_2 * element_width);
+
+    while (true) {
+        if (element_width < threshold) {
+            swapHelp(element_width, buffer, element_at_i, element_at_j);
+            return;
+        } else {
+            swapHelp(threshold, buffer, element_at_i, element_at_j);
+
+            element_at_i += threshold;
+            element_at_j += threshold;
+
+            element_width -= threshold;
+        }
+    }
+}
+
+fn partition(source_ptr: [*]u8, transform: Opaque, wrapper: CompareFn, element_width: usize, low: isize, high: isize) isize {
+    const pivot = source_ptr + (@intCast(usize, high) * element_width);
+    var i = (low - 1); // Index of smaller element and indicates the right position of pivot found so far
+    var j = low;
+
+    while (j <= high - 1) : (j += 1) {
+        const current_elem = source_ptr + (@intCast(usize, j) * element_width);
+
+        const ordering = wrapper(transform, current_elem, pivot);
+        const order = @intToEnum(utils.Ordering, ordering);
+
+        switch (order) {
+            utils.Ordering.LT => {
+                // the current element is smaller than the pivot; swap it
+                i += 1;
+                swap(source_ptr, element_width, @intCast(usize, i), @intCast(usize, j));
+            },
+            utils.Ordering.EQ, utils.Ordering.GT => {},
+        }
+    }
+    swap(source_ptr, element_width, @intCast(usize, i + 1), @intCast(usize, high));
+    return (i + 1);
+}
+
+fn quicksort(source_ptr: [*]u8, transform: Opaque, wrapper: CompareFn, element_width: usize, low: isize, high: isize) void {
+    if (low < high) {
+        // partition index
+        const pi = partition(source_ptr, transform, wrapper, element_width, low, high);
+
+        _ = quicksort(source_ptr, transform, wrapper, element_width, low, pi - 1); // before pi
+        _ = quicksort(source_ptr, transform, wrapper, element_width, pi + 1, high); // after pi
+    }
+}
+
+pub fn listSortWith(input: RocList, transform: Opaque, wrapper: CompareFn, alignment: usize, element_width: usize) callconv(.C) RocList {
+    var list = input.makeUnique(std.heap.c_allocator, alignment, element_width);
+
+    if (list.bytes) |source_ptr| {
+        const low = 0;
+        const high: isize = @intCast(isize, list.len()) - 1;
+        quicksort(source_ptr, transform, wrapper, element_width, low, high);
+    }
+
+    return list;
+}

compiler/builtins/bitcode/src/main.zig

@@ -20,6 +20,8 @@ comptime {
     exportListFn(list.listRepeat, "repeat");
     exportListFn(list.listAppend, "append");
     exportListFn(list.listRange, "range");
+    exportListFn(list.listReverse, "reverse");
+    exportListFn(list.listSortWith, "sort_with");
 }
 
 // Dict Module

compiler/builtins/bitcode/src/utils.zig

@@ -157,3 +157,9 @@ pub const RocResult = extern struct {
         return !self.isOk();
     }
 };
+
+pub const Ordering = packed enum(u8) {
+    EQ = 0,
+    GT = 1,
+    LT = 2,
+};

compiler/builtins/src/bitcode.rs

@@ -76,3 +76,5 @@ pub const LIST_CONTAINS: &str = "roc_builtins.list.contains";
 pub const LIST_REPEAT: &str = "roc_builtins.list.repeat";
 pub const LIST_APPEND: &str = "roc_builtins.list.append";
 pub const LIST_RANGE: &str = "roc_builtins.list.range";
+pub const LIST_REVERSE: &str = "roc_builtins.list.reverse";
+pub const LIST_SORT_WITH: &str = "roc_builtins.list.sort_with";

compiler/builtins/src/std.rs

@@ -958,6 +958,22 @@ pub fn types() -> MutMap<Symbol, (SolvedType, Region)> {
         top_level_function(vec![list_type(flex(TVAR1))], Box::new(bool_type())),
     );
 
+    // sortWith : List a, (a, a -> Ordering) -> List a
+    add_type(
+        Symbol::LIST_SORT_WITH,
+        top_level_function(
+            vec![
+                list_type(flex(TVAR1)),
+                closure(
+                    vec![flex(TVAR1), flex(TVAR1)],
+                    TVAR2,
+                    Box::new(ordering_type()),
+                ),
+            ],
+            Box::new(list_type(flex(TVAR1))),
+        ),
+    );
+
     // Dict module
 
     // Dict.hashTestOnly : Nat, v -> Nat

compiler/can/src/builtins.rs

@@ -91,6 +91,7 @@ pub fn builtin_defs_map(symbol: Symbol, var_store: &mut VarStore) -> Option<Def>
         LIST_WALK => list_walk,
         LIST_WALK_BACKWARDS => list_walk_backwards,
         LIST_WALK_UNTIL => list_walk_until,
+        LIST_SORT_WITH => list_sort_with,
         DICT_TEST_HASH => dict_hash_test_only,
         DICT_LEN => dict_len,
         DICT_EMPTY => dict_empty,
@@ -2118,6 +2119,11 @@ fn list_map3(symbol: Symbol, var_store: &mut VarStore) -> Def {
     lowlevel_4(symbol, LowLevel::ListMap3, var_store)
 }
 
+/// List.sortWith : List a, (a, a -> Ordering) -> List a
+fn list_sort_with(symbol: Symbol, var_store: &mut VarStore) -> Def {
+    lowlevel_2(symbol, LowLevel::ListSortWith, var_store)
+}
+
 /// Dict.hashTestOnly : k, v -> Nat
 fn dict_hash_test_only(symbol: Symbol, var_store: &mut VarStore) -> Def {
     lowlevel_2(symbol, LowLevel::Hash, var_store)

compiler/gen/src/llvm/bitcode.rs

@@ -1,9 +1,9 @@
+/// Helpers for interacting with the zig that generates bitcode
 use crate::debug_info_init;
-use crate::llvm::build::{set_name, Env, FAST_CALL_CONV};
+use crate::llvm::build::{set_name, Env, C_CALL_CONV, FAST_CALL_CONV};
 use crate::llvm::convert::basic_type_from_layout;
 use crate::llvm::refcounting::{decrement_refcount_layout, increment_refcount_layout, Mode};
 use inkwell::attributes::{Attribute, AttributeLoc};
-/// Helpers for interacting with the zig that generates bitcode
 use inkwell::types::{BasicType, BasicTypeEnum};
 use inkwell::values::{BasicValueEnum, CallSiteValue, FunctionValue, InstructionValue};
 use inkwell::AddressSpace;
@@ -383,3 +383,101 @@ pub fn build_eq_wrapper<'a, 'ctx, 'env>(
 
     function_value
 }
+
+pub fn build_compare_wrapper<'a, 'ctx, 'env>(
+    env: &Env<'a, 'ctx, 'env>,
+    layout_ids: &mut LayoutIds<'a>,
+    layout: &Layout<'a>,
+) -> FunctionValue<'ctx> {
+    let block = env.builder.get_insert_block().expect("to be in a function");
+    let di_location = env.builder.get_current_debug_location().unwrap();
+
+    let symbol = Symbol::GENERIC_COMPARE_REF;
+    let fn_name = layout_ids
+        .get(symbol, &layout)
+        .to_symbol_string(symbol, &env.interns);
+
+    let function_value = match env.module.get_function(fn_name.as_str()) {
+        Some(function_value) => function_value,
+        None => {
+            let arg_type = env.context.i8_type().ptr_type(AddressSpace::Generic);
+
+            let function_value = crate::llvm::refcounting::build_header_help(
+                env,
+                &fn_name,
+                env.context.i8_type().into(),
+                &[arg_type.into(), arg_type.into(), arg_type.into()],
+            );
+
+            // we expose this function to zig; must use c calling convention
+            function_value.set_call_conventions(C_CALL_CONV);
+
+            let kind_id = Attribute::get_named_enum_kind_id("alwaysinline");
+            debug_assert!(kind_id > 0);
+            let attr = env.context.create_enum_attribute(kind_id, 1);
+            function_value.add_attribute(AttributeLoc::Function, attr);
+
+            let entry = env.context.append_basic_block(function_value, "entry");
+            env.builder.position_at_end(entry);
+
+            debug_info_init!(env, function_value);
+
+            let mut it = function_value.get_param_iter();
+            let function_ptr = it.next().unwrap().into_pointer_value();
+            let value_ptr1 = it.next().unwrap().into_pointer_value();
+            let value_ptr2 = it.next().unwrap().into_pointer_value();
+
+            set_name(
+                function_ptr.into(),
+                Symbol::ARG_1.ident_string(&env.interns),
+            );
+            set_name(value_ptr1.into(), Symbol::ARG_2.ident_string(&env.interns));
+            set_name(value_ptr2.into(), Symbol::ARG_3.ident_string(&env.interns));
+
+            let value_type = basic_type_from_layout(env.arena, env.context, layout, env.ptr_bytes);
+            let function_type = env
+                .context
+                .i8_type()
+                .fn_type(&[value_type, value_type], false)
+                .ptr_type(AddressSpace::Generic);
+            let value_ptr_type = value_type.ptr_type(AddressSpace::Generic);
+
+            let function_cast =
+                env.builder
+                    .build_bitcast(function_ptr, function_type, "load_opaque");
+            let value_cast1 = env
+                .builder
+                .build_bitcast(value_ptr1, value_ptr_type, "load_opaque")
+                .into_pointer_value();
+
+            let value_cast2 = env
+                .builder
+                .build_bitcast(value_ptr2, value_ptr_type, "load_opaque")
+                .into_pointer_value();
+
+            let value1 = env.builder.build_load(value_cast1, "load_opaque");
+            let value2 = env.builder.build_load(value_cast2, "load_opaque");
+
+            let call = env.builder.build_call(
+                function_cast.into_pointer_value(),
+                &[value1, value2],
+                "call_user_defined_function",
+            );
+
+            let result = call.try_as_basic_value().left().unwrap();
+
+            // IMPORTANT! we call a user function, so it has the fast calling convention
+            call.set_call_convention(FAST_CALL_CONV);
+
+            env.builder.build_return(Some(&result));
+
+            function_value
+        }
+    };
+
+    env.builder.position_at_end(block);
+    env.builder
+        .set_current_debug_location(env.context, di_location);
+
+    function_value
+}

compiler/gen/src/llvm/build.rs

@@ -8,7 +8,7 @@ use crate::llvm::build_list::{
     allocate_list, empty_list, empty_polymorphic_list, list_append, list_concat, list_contains,
     list_get_unsafe, list_join, list_keep_errs, list_keep_if, list_keep_oks, list_len, list_map,
     list_map2, list_map3, list_map_with_index, list_prepend, list_range, list_repeat, list_reverse,
-    list_set, list_single, list_walk_help,
+    list_set, list_single, list_sort_with, list_walk_help,
 };
 use crate::llvm::build_str::{
     str_concat, str_count_graphemes, str_ends_with, str_from_float, str_from_int, str_from_utf8,
@@ -3693,7 +3693,7 @@ fn run_low_level<'a, 'ctx, 'env>(
 
             let inplace = get_inplace_from_layout(layout);
 
-            list_reverse(env, parent, inplace, list, list_layout)
+            list_reverse(env, inplace, list, list_layout)
         }
         ListConcat => {
             debug_assert_eq!(args.len(), 2);
@@ -3949,6 +3949,22 @@ fn run_low_level<'a, 'ctx, 'env>(
 
             list_join(env, inplace, parent, list, outer_list_layout)
         }
+        ListSortWith => {
+            // List.sortWith : List a, (a, a -> Ordering) -> List a
+            debug_assert_eq!(args.len(), 2);
+
+            let (list, list_layout) = load_symbol_and_layout(scope, &args[0]);
+
+            let func = load_symbol(scope, &args[1]);
+
+            match list_layout {
+                Layout::Builtin(Builtin::EmptyList) => empty_list(env),
+                Layout::Builtin(Builtin::List(_, element_layout)) => {
+                    list_sort_with(env, layout_ids, func, list, element_layout)
+                }
+                _ => unreachable!("invalid list layout"),
+            }
+        }
         NumAbs | NumNeg | NumRound | NumSqrtUnchecked | NumLogUnchecked | NumSin | NumCos
         | NumCeiling | NumFloor | NumToFloat | NumIsFinite | NumAtan | NumAcos | NumAsin => {
             debug_assert_eq!(args.len(), 1);

compiler/gen/src/llvm/build_list.rs

@@ -1,7 +1,7 @@
 #![allow(clippy::too_many_arguments)]
 use crate::llvm::bitcode::{
-    build_dec_wrapper, build_eq_wrapper, build_inc_wrapper, build_transform_caller,
-    call_bitcode_fn, call_void_bitcode_fn,
+    build_compare_wrapper, build_dec_wrapper, build_eq_wrapper, build_inc_wrapper,
+    build_transform_caller, call_bitcode_fn, call_void_bitcode_fn,
 };
 use crate::llvm::build::{
     allocate_with_refcount_help, cast_basic_basic, complex_bitcast, Env, InPlace,
@@ -12,7 +12,6 @@ use crate::llvm::refcounting::{
 };
 use inkwell::builder::Builder;
 use inkwell::context::Context;
-use inkwell::types::BasicType;
 use inkwell::types::{BasicTypeEnum, PointerType};
 use inkwell::values::{BasicValueEnum, FunctionValue, IntValue, PointerValue, StructValue};
 use inkwell::{AddressSpace, IntPredicate};
@@ -337,93 +336,14 @@ pub fn list_join<'a, 'ctx, 'env>(
     }
 }
 
-/// List.reverse : List elem -> List elem
-pub fn list_reverse_help<'a, 'ctx, 'env>(
-    env: &Env<'a, 'ctx, 'env>,
-    parent: FunctionValue<'ctx>,
-    inplace: InPlace,
-    length: IntValue<'ctx>,
-    source_ptr: PointerValue<'ctx>,
-    dest_ptr: PointerValue<'ctx>,
-) {
-    let builder = env.builder;
-    let ctx = env.context;
-
-    // constant 1i64
-    let one = ctx.i64_type().const_int(1, false);
-
-    let low_alloca = builder.build_alloca(ctx.i64_type(), "low");
-    let high_alloca = builder.build_alloca(ctx.i64_type(), "high");
-
-    let high_val = builder.build_int_sub(length, one, "subtract 1");
-
-    builder.build_store(low_alloca, ctx.i64_type().const_zero());
-    builder.build_store(high_alloca, high_val);
-
-    // while (high > low)
-    let condition_bb = ctx.append_basic_block(parent, "condition");
-    builder.build_unconditional_branch(condition_bb);
-    builder.position_at_end(condition_bb);
-
-    let high = builder.build_load(high_alloca, "high").into_int_value();
-    let low = builder.build_load(low_alloca, "low").into_int_value();
-
-    // if updating in-place, then the "middle element" can be left untouched
-    // otherwise, the middle element needs to be copied over from the source to the target
-    let predicate = match inplace {
-        InPlace::InPlace => IntPredicate::SGT,
-        InPlace::Clone => IntPredicate::SGE,
-    };
-
-    let condition = builder.build_int_compare(predicate, high, low, "loopcond");
-
-    let body_bb = ctx.append_basic_block(parent, "body");
-    let cont_bb = ctx.append_basic_block(parent, "cont");
-    builder.build_conditional_branch(condition, body_bb, cont_bb);
-
-    // loop body
-    builder.position_at_end(body_bb);
-
-    // assumption: calculating pointer offsets for both the source and target is
-
-    let mut low_ptr = unsafe { builder.build_in_bounds_gep(source_ptr, &[low], "low_ptr") };
-    let mut high_ptr = unsafe { builder.build_in_bounds_gep(source_ptr, &[high], "high_ptr") };
-
-    // TODO use memmove?
-    let low_value = builder.build_load(low_ptr, "load_low");
-    let high_value = builder.build_load(high_ptr, "load_high");
-
-    // swap the two values
-    if let InPlace::Clone = inplace {
-        low_ptr = unsafe { builder.build_in_bounds_gep(dest_ptr, &[low], "low_ptr") };
-        high_ptr = unsafe { builder.build_in_bounds_gep(dest_ptr, &[high], "high_ptr") };
-    }
-
-    builder.build_store(high_ptr, low_value);
-    builder.build_store(low_ptr, high_value);
-
-    builder.build_store(low_alloca, builder.build_int_add(low, one, "increment"));
-    builder.build_store(high_alloca, builder.build_int_sub(high, one, "decrement"));
-
-    builder.build_unconditional_branch(condition_bb);
-
-    // continuation
-    builder.position_at_end(cont_bb);
-}
-
 /// List.reverse : List elem -> List elem
 pub fn list_reverse<'a, 'ctx, 'env>(
     env: &Env<'a, 'ctx, 'env>,
-    parent: FunctionValue<'ctx>,
-    output_inplace: InPlace,
+    _output_inplace: InPlace,
     list: BasicValueEnum<'ctx>,
     list_layout: &Layout<'a>,
 ) -> BasicValueEnum<'ctx> {
-    let builder = env.builder;
-    let ctx = env.context;
-
-    let wrapper_struct = list.into_struct_value();
-    let (input_inplace, element_layout) = match *list_layout {
+    let (_, element_layout) = match *list_layout {
         Layout::Builtin(Builtin::EmptyList) => (
             InPlace::InPlace,
             // this pointer will never actually be dereferenced
@@ -440,74 +360,27 @@ pub fn list_reverse<'a, 'ctx, 'env>(
         _ => unreachable!("Invalid layout {:?} in List.reverse", list_layout),
     };
 
-    let list_type = basic_type_from_layout(env.arena, env.context, &element_layout, env.ptr_bytes);
-    let ptr_type = list_type.ptr_type(AddressSpace::Generic);
+    let list_i128 = complex_bitcast(env.builder, list, env.context.i128_type().into(), "to_i128");
 
-    let list_ptr = load_list_ptr(builder, wrapper_struct, ptr_type);
-    let length = list_len(builder, list.into_struct_value());
+    let element_width = env
+        .ptr_int()
+        .const_int(element_layout.stack_size(env.ptr_bytes) as u64, false);
 
-    match input_inplace {
-        InPlace::InPlace => {
-            list_reverse_help(env, parent, input_inplace, length, list_ptr, list_ptr);
+    let alignment = element_layout.alignment_bytes(env.ptr_bytes);
+    let alignment_iv = env.ptr_int().const_int(alignment as u64, false);
 
-            list
-        }
-
-        InPlace::Clone => {
-            let len_0_block = ctx.append_basic_block(parent, "len_0_block");
-            let len_1_block = ctx.append_basic_block(parent, "len_1_block");
-            let len_n_block = ctx.append_basic_block(parent, "len_n_block");
-            let cont_block = ctx.append_basic_block(parent, "cont_block");
-
-            let one = ctx.i64_type().const_int(1, false);
-            let zero = ctx.i64_type().const_zero();
-
-            let result = builder.build_alloca(ptr_type, "result");
-
-            builder.build_switch(
-                length,
-                len_n_block,
-                &[(zero, len_0_block), (one, len_1_block)],
+    let output = call_bitcode_fn(
+        env,
+        &[list_i128, alignment_iv.into(), element_width.into()],
+        &bitcode::LIST_REVERSE,
     );
 
-            // build block for length 0
-            {
-                builder.position_at_end(len_0_block);
-
-                // store NULL pointer there
-                builder.build_store(result, ptr_type.const_zero());
-                builder.build_unconditional_branch(cont_block);
-            }
-
-            // build block for length 1
-            {
-                builder.position_at_end(len_1_block);
-
-                let new_list_ptr = clone_list(env, output_inplace, &element_layout, one, list_ptr);
-
-                builder.build_store(result, new_list_ptr);
-                builder.build_unconditional_branch(cont_block);
-            }
-
-            // build block for length > 1
-            {
-                builder.position_at_end(len_n_block);
-
-                let new_list_ptr = allocate_list(env, output_inplace, &element_layout, length);
-
-                list_reverse_help(env, parent, InPlace::Clone, length, list_ptr, new_list_ptr);
-
-                // store new list pointer there
-                builder.build_store(result, new_list_ptr);
-                builder.build_unconditional_branch(cont_block);
-            }
-
-            builder.position_at_end(cont_block);
-            let new_list_ptr = builder.build_load(result, "result").into_pointer_value();
-
-            store_list(env, new_list_ptr, length)
-        }
-    }
+    complex_bitcast(
+        env.builder,
+        output,
+        collection(env.context, env.ptr_bytes).into(),
+        "from_i128",
+    )
 }
 
 pub fn list_get_unsafe<'a, 'ctx, 'env>(
@@ -1132,6 +1005,52 @@ pub fn list_keep_result<'a, 'ctx, 'env>(
     )
 }
 
+/// List.sortWith : List a, (a, a -> Ordering) -> List a
+pub fn list_sort_with<'a, 'ctx, 'env>(
+    env: &Env<'a, 'ctx, 'env>,
+    layout_ids: &mut LayoutIds<'a>,
+    transform: BasicValueEnum<'ctx>,
+    list: BasicValueEnum<'ctx>,
+    element_layout: &Layout<'a>,
+) -> BasicValueEnum<'ctx> {
+    let u8_ptr = env.context.i8_type().ptr_type(AddressSpace::Generic);
+
+    let list_i128 = complex_bitcast(env.builder, list, env.context.i128_type().into(), "to_i128");
+
+    let transform_ptr = transform.into_pointer_value();
+
+    let compare_wrapper = build_compare_wrapper(env, layout_ids, element_layout)
+        .as_global_value()
+        .as_pointer_value();
+
+    let element_width = env
+        .ptr_int()
+        .const_int(element_layout.stack_size(env.ptr_bytes) as u64, false);
+
+    let alignment = element_layout.alignment_bytes(env.ptr_bytes);
+    let alignment_iv = env.ptr_int().const_int(alignment as u64, false);
+
+    let output = call_bitcode_fn(
+        env,
+        &[
+            list_i128,
+            env.builder
+                .build_bitcast(transform_ptr, u8_ptr, "to_opaque"),
+            compare_wrapper.into(),
+            alignment_iv.into(),
+            element_width.into(),
+        ],
+        bitcode::LIST_SORT_WITH,
+    );
+
+    complex_bitcast(
+        env.builder,
+        output,
+        collection(env.context, env.ptr_bytes).into(),
+        "from_i128",
+    )
+}
+
 /// List.map : List before, (before -> after) -> List after
 pub fn list_map<'a, 'ctx, 'env>(
     env: &Env<'a, 'ctx, 'env>,

compiler/module/src/low_level.rs

@@ -37,6 +37,7 @@ pub enum LowLevel {
     ListWalkBackwards,
     ListKeepOks,
     ListKeepErrs,
+    ListSortWith,
     DictSize,
     DictEmpty,
     DictInsert,

compiler/module/src/symbol.rs

@@ -756,6 +756,9 @@ define_builtins! {
 
         // A caller (wrapper) that we pass to zig for it to be able to call Roc functions
         20 ZIG_FUNCTION_CALLER: "#zig_function_caller"
+
+        // a caller (wrapper) for comparison
+        21 GENERIC_COMPARE_REF: "#generic_compare_ref"
     }
     1 NUM: "Num" => {
         0 NUM_NUM: "Num" imported // the Num.Num type alias
@@ -919,6 +922,7 @@ define_builtins! {
         28 LIST_PRODUCT_MUL: "#productmul"
         29 LIST_WALK_UNTIL: "walkUntil"
         30 LIST_RANGE: "range"
+        31 LIST_SORT_WITH: "sortWith"
     }
     5 RESULT: "Result" => {
         0 RESULT_RESULT: "Result" imported // the Result.Result type alias

compiler/mono/src/borrow.rs

@@ -659,6 +659,7 @@ pub fn lowlevel_borrow_signature(arena: &Bump, op: LowLevel) -> &[bool] {
         ListWalk | ListWalkUntil | ListWalkBackwards => {
             arena.alloc_slice_copy(&[owned, irrelevant, owned])
         }
+        ListSortWith => arena.alloc_slice_copy(&[owned, irrelevant]),
 
         // TODO when we have lists with capacity (if ever)
         // List.append should own its first argument

compiler/test_gen/src/gen_list.rs

@@ -1839,19 +1839,30 @@ fn cleanup_because_exception() {
 
 #[test]
 fn list_range() {
+    assert_evals_to!("List.range 0 -1", RocList::from_slice(&[]), RocList<i64>);
+    assert_evals_to!("List.range 0 0", RocList::from_slice(&[0]), RocList<i64>);
     assert_evals_to!(
-        indoc!("List.range 0 -1"),
-        RocList::from_slice(&[]),
-        RocList<i64>
-    );
-    assert_evals_to!(
-        indoc!("List.range 0 0"),
-        RocList::from_slice(&[0]),
-        RocList<i64>
-    );
-    assert_evals_to!(
-        indoc!("List.range 0 5"),
+        "List.range 0 5",
         RocList::from_slice(&[0, 1, 2, 3, 4]),
         RocList<i64>
     );
 }
+
+#[test]
+fn list_sort_with() {
+    assert_evals_to!(
+        "List.sortWith [] Num.compare",
+        RocList::from_slice(&[]),
+        RocList<i64>
+    );
+    assert_evals_to!(
+        "List.sortWith [ 4,3,2,1 ] Num.compare",
+        RocList::from_slice(&[1, 2, 3, 4]),
+        RocList<i64>
+    );
+    assert_evals_to!(
+        "List.sortWith [ 1,2,3,4] (\\a,b -> Num.compare b a)",
+        RocList::from_slice(&[4, 3, 2, 1]),
+        RocList<i64>
+    );
+}

editor/src/editor/code_lines.rs

@@ -4,6 +4,7 @@ use crate::ui::util::slice_get;
 use crate::ui::util::slice_get_mut;
 use bumpalo::collections::String as BumpString;
 use bumpalo::Bump;
+use std::fmt;
 
 #[derive(Debug)]
 pub struct CodeLines {
@@ -104,3 +105,21 @@ impl Lines for CodeLines {
         Ok(self.get_line(line_nr)?.chars().last())
     }
 }
+
+impl fmt::Display for CodeLines {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        for row in &self.lines {
+            let row_str = row
+                .chars()
+                .map(|code_char| format!("'{}'", code_char))
+                .collect::<Vec<String>>()
+                .join(", ");
+
+            write!(f, "\n{}", row_str)?;
+        }
+
+        write!(f, "      (code_lines)")?;
+
+        Ok(())
+    }
+}

editor/src/editor/grid_node_map.rs

@@ -4,6 +4,7 @@ use crate::editor::util::index_of;
 use crate::ui::text::text_pos::TextPos;
 use crate::ui::ui_error::UIResult;
 use crate::ui::util::{slice_get, slice_get_mut};
+use std::fmt;
 
 #[derive(Debug)]
 pub struct GridNodeMap {
@@ -72,3 +73,21 @@ impl GridNodeMap {
         Ok(caret_pos.column - first_node_index)
     }
 }
+
+impl fmt::Display for GridNodeMap {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        for row in &self.lines {
+            let row_str = row
+                .iter()
+                .map(|mark_node_id| format!(" {} ", mark_node_id))
+                .collect::<Vec<String>>()
+                .join(", ");
+
+            write!(f, "{}", row_str)?;
+        }
+
+        write!(f, "      (grid_node_map)")?;
+
+        Ok(())
+    }
+}

editor/src/editor/keyboard_input.rs

@@ -42,6 +42,8 @@ pub fn handle_keydown(
 
         A | Home | End => pass_keydown_to_focused(&modifiers, virtual_keycode, app_model)?,
 
+        F11 => pass_keydown_to_focused(&modifiers, virtual_keycode, app_model)?,
+
         _ => (),
     }
 

editor/src/editor/main.rs

@@ -307,9 +307,11 @@ fn run_event_loop(file_path_opt: Option<&Path>) -> Result<(), Box<dyn Error>> {
                     }
 
                     if let Some(ref rendered_wgpu) = rendered_wgpu_opt {
-                        let borrowed_text = rendered_wgpu.text.to_borrowed();
+                        for text_section in &rendered_wgpu.text_sections {
+                            let borrowed_text = text_section.to_borrowed();
 
                             glyph_brush.queue(borrowed_text);
+                        }
 
                         draw_all_rects(
                             &rendered_wgpu.rects,

editor/src/editor/markup/nodes.rs

@@ -12,6 +12,7 @@ use crate::lang::{
     pool::{NodeId, PoolStr},
 };
 use bumpalo::Bump;
+use std::fmt;
 
 #[derive(Debug)]
 pub enum MarkupNode {
@@ -342,3 +343,49 @@ pub fn set_parent_for_all_helper(
         MarkupNode::Blank { parent_id_opt, .. } => *parent_id_opt = Some(parent_node_id),
     }
 }
+
+impl fmt::Display for MarkupNode {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        writeln!(
+            f,
+            "{} ({})",
+            self.node_type_as_string(),
+            self.get_content().unwrap_or_else(|_| "".to_string())
+        )
+    }
+}
+
+pub fn tree_as_string(root_node_id: MarkNodeId, mark_node_pool: &SlowPool) -> String {
+    let mut full_string = "\n\n(mark_node_tree)\n".to_owned();
+
+    let node = mark_node_pool.get(root_node_id);
+
+    full_string.push_str(&format!("{}", node));
+
+    tree_as_string_helper(node, 1, &mut full_string, mark_node_pool);
+
+    full_string
+}
+
+fn tree_as_string_helper(
+    node: &MarkupNode,
+    level: usize,
+    tree_string: &mut String,
+    mark_node_pool: &SlowPool,
+) {
+    for child_id in node.get_children_ids() {
+        let mut full_str = std::iter::repeat("|--- ")
+            .take(level)
+            .collect::<Vec<&str>>()
+            .join("")
+            .to_owned();
+
+        let child = mark_node_pool.get(child_id);
+
+        full_str.push_str(&format!("{}", child));
+
+        tree_string.push_str(&full_str);
+
+        tree_as_string_helper(child, level + 1, tree_string, mark_node_pool);
+    }
+}

editor/src/editor/mod.rs

@@ -7,6 +7,7 @@ pub mod main;
 mod markup;
 mod mvc;
 mod render_ast;
+mod render_debug;
 mod resources;
 mod slow_pool;
 mod style;

editor/src/editor/mvc/ed_model.rs

@@ -34,6 +34,7 @@ pub struct EdModel<'a> {
     pub has_focus: bool,
     // Option<MarkNodeId>: MarkupNode that corresponds to caret position, Option because this MarkNodeId is only calculated when it needs to be used.
     pub caret_w_select_vec: NonEmpty<(CaretWSelect, Option<MarkNodeId>)>,
+    pub show_debug_view: bool,
     // EdModel is dirty if it has changed since the previous render.
     pub dirty: bool,
 }
@@ -83,6 +84,7 @@ pub fn init_model<'a>(
         glyph_dim_rect_opt: None,
         has_focus: true,
         caret_w_select_vec: NonEmpty::new((CaretWSelect::default(), None)),
+        show_debug_view: false,
         dirty: true,
     })
 }

editor/src/editor/mvc/ed_update.rs

@@ -281,6 +281,11 @@ impl<'a> SelectableLines for EdModel<'a> {
             }
             Home => self.move_caret_home(modifiers),
             End => self.move_caret_end(modifiers),
+            F11 => {
+                self.show_debug_view = !self.show_debug_view;
+                self.dirty = true;
+                Ok(())
+            }
             _ => Ok(()),
         }
     }
@@ -371,9 +376,6 @@ pub fn handle_new_char(received_char: &char, ed_model: &mut EdModel) -> EdResult
                 };
 
             let ast_node_id = curr_mark_node.get_ast_node_id();
-
-
-
             let ast_node_ref = ed_model.module.env.pool.get(ast_node_id);
 
             match ast_node_ref {

editor/src/editor/mvc/ed_view.rs

@@ -2,6 +2,7 @@ use super::ed_model::EdModel;
 use crate::editor::config::Config;
 use crate::editor::ed_error::EdResult;
 use crate::editor::render_ast::build_code_graphics;
+use crate::editor::render_debug::build_debug_graphics;
 use crate::graphics::primitives::rect::Rect;
 use crate::ui::text::caret_w_select::make_caret_rect;
 use crate::ui::text::caret_w_select::CaretWSelect;
@@ -12,7 +13,7 @@ use winit::dpi::PhysicalSize;
 
 #[derive(Debug)]
 pub struct RenderedWgpu {
-    pub text: glyph_brush::OwnedSection,
+    pub text_sections: Vec<glyph_brush::OwnedSection>,
     pub rects: Vec<Rect>,
 }
 
@@ -25,7 +26,9 @@ pub fn model_to_wgpu<'a>(
 ) -> EdResult<RenderedWgpu> {
     let glyph_dim_rect = ed_model.glyph_dim_rect_opt.context(MissingGlyphDims {})?;
 
-    let (section, mut rects) = build_code_graphics(
+    let mut all_text_sections = Vec::new();
+
+    let (code_section, mut rects) = build_code_graphics(
         ed_model.markup_node_pool.get(ed_model.markup_root_id),
         size,
         txt_coords,
@@ -34,6 +37,8 @@ pub fn model_to_wgpu<'a>(
         &ed_model.markup_node_pool,
     )?;
 
+    all_text_sections.push(code_section);
+
     let caret_w_sel_vec = ed_model
         .caret_w_select_vec
         .iter()
@@ -45,8 +50,12 @@ pub fn model_to_wgpu<'a>(
 
     rects.append(&mut sel_rects);
 
+    if ed_model.show_debug_view {
+        all_text_sections.push(build_debug_graphics(size, txt_coords, config, ed_model)?);
+    }
+
     Ok(RenderedWgpu {
-        text: section,
+        text_sections: all_text_sections,
         rects,
     })
 }

editor/src/editor/mvc/record_update.rs

@@ -11,9 +11,7 @@ use crate::editor::slow_pool::MarkNodeId;
 use crate::editor::syntax_highlight::HighlightStyle;
 use crate::editor::util::index_of;
 use crate::lang::ast::Expr2;
-use crate::lang::pool::NodeId;
-use crate::lang::pool::PoolStr;
-use crate::lang::pool::PoolVec;
+use crate::lang::pool::{NodeId, PoolStr, PoolVec};
 use crate::ui::text::text_pos::TextPos;
 use roc_types::subs::Variable;
 use snafu::OptionExt;
@@ -202,17 +200,29 @@ pub fn update_record_field(
 
     let mut new_field_name = String::new();
 
-    first_field.0.as_str(ed_model.module.env.pool).to_string();
-
+    // -push old field name
+    new_field_name.push_str(first_field.0.as_str(ed_model.module.env.pool));
     new_field_name.push_str(new_input);
 
+    // -clone to prevent borrow issues
+    let field_val_id = first_field.2;
+
     let new_pool_str = PoolStr::new(&new_field_name, &mut ed_model.module.env.pool);
 
+    if let Expr2::InvalidLookup(_) = ed_model.module.env.pool.get(field_val_id) {
+        ed_model
+            .module
+            .env
+            .pool
+            .set(field_val_id, Expr2::InvalidLookup(new_pool_str));
+    }
+
     let first_field_mut = record_fields
         .iter_mut(ed_model.module.env.pool)
         .next()
         .with_context(|| RecordWithoutFields {})?;
 
+    // -update field name
     first_field_mut.0 = new_pool_str;
 
     Ok(())
@@ -239,6 +249,17 @@ pub fn update_record_colon(ed_model: &mut EdModel) -> EdResult<()> {
                 record_var: _,
                 fields,
             } => {
+                // update AST node
+                let new_field_val = Expr2::Blank;
+                let new_field_val_id = ed_model.module.env.pool.add(new_field_val);
+
+                let first_field_mut = fields
+                    .iter_mut(ed_model.module.env.pool)
+                    .next()
+                    .with_context(|| RecordWithoutFields {})?;
+
+                first_field_mut.2 = new_field_val_id;
+
                 // update Markup
                 let record_colon = nodes::COLON;
 
@@ -257,7 +278,7 @@ pub fn update_record_colon(ed_model: &mut EdModel) -> EdResult<()> {
                     .add_child_at_index(new_child_index, record_colon_node_id)?;
 
                 let record_blank_node = MarkupNode::Blank {
-                    ast_node_id,
+                    ast_node_id: new_field_val_id,
                     syn_high_style: HighlightStyle::Blank,
                     attributes: Attributes::new(),
                     parent_id_opt: Some(parent_id),
@@ -288,17 +309,6 @@ pub fn update_record_colon(ed_model: &mut EdModel) -> EdResult<()> {
                     nodes::BLANK_PLACEHOLDER,
                     record_blank_node_id,
                 )?;
-
-                // update AST node
-                let new_field_val = Expr2::Blank;
-                let new_field_val_id = ed_model.module.env.pool.add(new_field_val);
-
-                let first_field_mut = fields
-                    .iter_mut(ed_model.module.env.pool)
-                    .next()
-                    .with_context(|| RecordWithoutFields {})?;
-
-                first_field_mut.2 = new_field_val_id;
             }
             other => unimplemented!("TODO implement updating of Expr2 {:?}.", other),
         }

editor/src/editor/render_debug.rs

@@ -0,0 +1,64 @@
+use crate::editor::ed_error::EdResult;
+use crate::editor::markup::nodes::tree_as_string;
+use crate::editor::mvc::ed_model::EdModel;
+use crate::graphics::colors;
+use crate::graphics::colors::from_hsb;
+use crate::graphics::primitives::text as gr_text;
+use crate::lang::ast::expr2_to_string;
+use cgmath::Vector2;
+use winit::dpi::PhysicalSize;
+
+use crate::editor::config::Config;
+
+pub fn build_debug_graphics(
+    size: &PhysicalSize<u32>,
+    txt_coords: Vector2<f32>,
+    config: &Config,
+    ed_model: &EdModel,
+) -> EdResult<glyph_brush::OwnedSection> {
+    let area_bounds = (size.width as f32, size.height as f32);
+    let layout = wgpu_glyph::Layout::default().h_align(wgpu_glyph::HorizontalAlign::Left);
+
+    let debug_txt_coords: Vector2<f32> = (txt_coords.x, txt_coords.y * 6.0).into();
+
+    let grid_node_map_text = glyph_brush::OwnedText::new(format!("{}", ed_model.grid_node_map))
+        .with_color(colors::to_slice(from_hsb(20, 41, 100)))
+        .with_scale(config.code_font_size);
+
+    let code_lines_text = glyph_brush::OwnedText::new(format!("{}", ed_model.code_lines))
+        .with_color(colors::to_slice(from_hsb(0, 49, 96)))
+        .with_scale(config.code_font_size);
+
+    let mark_node_tree_text = glyph_brush::OwnedText::new(tree_as_string(
+        ed_model.markup_root_id,
+        &ed_model.markup_node_pool,
+    ))
+    .with_color(colors::to_slice(from_hsb(266, 31, 96)))
+    .with_scale(config.code_font_size);
+
+    let mark_node_pool_text = glyph_brush::OwnedText::new(format!("{}", ed_model.markup_node_pool))
+        .with_color(colors::to_slice(from_hsb(110, 45, 82)))
+        .with_scale(config.code_font_size);
+
+    let ast_node_text = glyph_brush::OwnedText::new(format!(
+        "\n\n(ast_root)\n{}",
+        expr2_to_string(ed_model.module.ast_root_id, ed_model.module.env.pool)
+    ))
+    .with_color(colors::to_slice(from_hsb(211, 80, 100)))
+    .with_scale(config.code_font_size);
+
+    let section = gr_text::section_from_glyph_text(
+        vec![
+            grid_node_map_text,
+            code_lines_text,
+            mark_node_tree_text,
+            mark_node_pool_text,
+            ast_node_text,
+        ],
+        debug_txt_coords.into(),
+        area_bounds,
+        layout,
+    );
+
+    Ok(section)
+}

editor/src/editor/slow_pool.rs

@@ -1,4 +1,5 @@
 use crate::editor::markup::nodes::MarkupNode;
+use std::fmt;
 
 pub type MarkNodeId = usize;
 
@@ -34,3 +35,21 @@ impl SlowPool {
         self.nodes[node_id] = new_node;
     }
 }
+
+impl fmt::Display for SlowPool {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "\n\n(mark_node_pool)\n")?;
+
+        for (index, node) in self.nodes.iter().enumerate() {
+            writeln!(
+                f,
+                "{}: {} ({})",
+                index,
+                node.node_type_as_string(),
+                node.get_content().unwrap_or_else(|_| "".to_string()),
+            )?;
+        }
+
+        Ok(())
+    }
+}

editor/src/lang/ast.rs

@@ -1,4 +1,5 @@
 use crate::lang::pattern::{Pattern2, PatternId};
+use crate::lang::pool::Pool;
 use crate::lang::pool::{NodeId, PoolStr, PoolVec, ShallowClone};
 use crate::lang::types::{Type2, TypeId};
 use arraystring::{typenum::U30, ArrayString};
@@ -301,6 +302,83 @@ pub struct WhenBranch {
 
 pub type ExprId = NodeId<Expr2>;
 
+pub fn expr2_to_string(node_id: NodeId<Expr2>, pool: &Pool) -> String {
+    let mut full_string = String::new();
+
+    expr2_to_string_helper(node_id, 0, pool, &mut full_string);
+
+    full_string
+}
+
+fn get_spacing(indent_level: usize) -> String {
+    std::iter::repeat("    ")
+        .take(indent_level)
+        .collect::<Vec<&str>>()
+        .join("")
+}
+
+fn expr2_to_string_helper(
+    node_id: NodeId<Expr2>,
+    indent_level: usize,
+    pool: &Pool,
+    out_string: &mut String,
+) {
+    let expr2 = pool.get(node_id);
+
+    out_string.push_str(&get_spacing(indent_level));
+
+    match expr2 {
+        Expr2::SmallStr(arr_string) => out_string.push_str(&format!(
+            "{}{}{}",
+            "SmallStr(\"",
+            arr_string.as_str(),
+            "\")",
+        )),
+        Expr2::Str(pool_str) => {
+            out_string.push_str(&format!("{}{}{}", "Str(\"", pool_str.as_str(pool), "\")",))
+        }
+        Expr2::Blank => out_string.push_str("Blank"),
+        Expr2::EmptyRecord => out_string.push_str("EmptyRecord"),
+        Expr2::Record { record_var, fields } => {
+            out_string.push_str("Record:\n");
+            out_string.push_str(&format!(
+                "{}Var({:?})\n",
+                get_spacing(indent_level + 1),
+                record_var
+            ));
+
+            out_string.push_str(&format!("{}fields: [\n", get_spacing(indent_level + 1)));
+
+            let mut first_child = true;
+            for (pool_str, var, val_node_id) in fields.iter(pool) {
+                if !first_child {
+                    out_string.push_str(", ")
+                } else {
+                    first_child = false;
+                }
+
+                out_string.push_str(&format!(
+                    "{}({}, Var({:?}), Expr2(\n",
+                    get_spacing(indent_level + 2),
+                    pool_str.as_str(pool),
+                    var,
+                ));
+
+                expr2_to_string_helper(*val_node_id, indent_level + 3, pool, out_string);
+                out_string.push_str(&format!("{})\n", get_spacing(indent_level + 2)));
+            }
+
+            out_string.push_str(&format!("{}]\n", get_spacing(indent_level + 1)));
+        }
+        Expr2::InvalidLookup(pool_str) => {
+            out_string.push_str(&format!("InvalidLookup({})", pool_str.as_str(pool)));
+        }
+        other => todo!("Implement for {:?}", other),
+    }
+
+    out_string.push('\n');
+}
+
 #[test]
 fn size_of_expr() {
     assert_eq!(std::mem::size_of::<Expr2>(), crate::lang::pool::NODE_BYTES);

editor/src/lang/pool.rs

@@ -205,7 +205,7 @@ impl Drop for Pool {
 }
 
 /// A string containing at most 2^32 pool-allocated bytes.
-#[derive(Debug)]
+#[derive(Debug, Copy, Clone)]
 pub struct PoolStr {
     first_node_id: NodeId<()>,
     len: u32,

examples/cli/.gitignore

@@ -0,0 +1 @@
+echo

examples/cli/Echo.roc

@@ -0,0 +1,16 @@
+app "echo"
+    packages { base: "platform" }
+    imports [ base.Task.{ await }, base.Stdout, base.Stdin ]
+    provides [ main ] to base
+
+main : Task.Task {} *
+main =
+    {} <- await (Stdout.line "What's your first name?")
+
+    firstName <- await Stdin.line
+
+    {} <- await (Stdout.line "What's your last name?")
+
+    lastName <- await Stdin.line
+
+    Stdout.line "Hi, \(firstName) \(lastName)!"

examples/cli/platform/Cargo.lock

@@ -0,0 +1,23 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "host"
+version = "0.1.0"
+dependencies = [
+ "roc_std 0.1.0",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.79"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "roc_std"
+version = "0.1.0"
+dependencies = [
+ "libc 0.2.79 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[metadata]
+"checksum libc 0.2.79 (registry+https://github.com/rust-lang/crates.io-index)" = "2448f6066e80e3bfc792e9c98bf705b4b0fc6e8ef5b43e5889aff0eaa9c58743"

examples/cli/platform/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "host"
+version = "0.1.0"
+authors = ["Richard Feldman <oss@rtfeldman.com>"]
+edition = "2018"
+
+[lib]
+crate-type = ["staticlib"]
+
+[dependencies]
+roc_std = { path = "../../../roc_std" }
+
+[workspace]

examples/cli/platform/Pkg-Config.roc

@@ -0,0 +1,16 @@
+platform rtfeldman/roc-cli
+    requires { main : Task.Task {} * } # TODO FIXME
+    exposes [] # TODO FIXME actually expose modules
+    packages {}
+    imports [ Task ] # TODO FIXME Task.{ Task }
+    provides [ mainForHost ]
+    effects fx.Effect
+        {
+            putChar : I64 -> Effect {},
+            putLine : Str -> Effect {},
+            getLine : Effect Str
+        }
+
+
+mainForHost : Task.Task {} * as Fx # TODO FIXME Task.Task {} []
+mainForHost = main

examples/cli/platform/Stdin.roc

@@ -0,0 +1,6 @@
+interface Stdin
+    exposes [ line ]
+    imports [ fx.Effect, Task ]
+
+line : Task.Task Str *
+line = Effect.after Effect.getLine Task.succeed # TODO FIXME Effect.getLine should suffice

examples/cli/platform/Stdout.roc

@@ -0,0 +1,6 @@
+interface Stdout
+    exposes [ line ]
+    imports [ fx.Effect, Task ] # TODO FIXME Task.{ Task }
+
+line : Str -> Task.Task {} *
+line = \str -> Effect.map (Effect.putLine str) (\_ -> Ok {})

examples/cli/platform/Task.roc

@@ -0,0 +1,34 @@
+interface Task
+    exposes [ Task, succeed, fail, await, map, putLine ]
+    imports [ fx.Effect ]
+
+
+Task ok err : Effect.Effect (Result ok err)
+
+
+succeed : val -> Task val *
+succeed = \val ->
+    Effect.always (Ok val)
+
+
+fail : err -> Task * err
+fail = \val ->
+    Effect.always (Err val)
+
+
+await : Task a err, (a -> Task b err) -> Task b err
+await = \effect, transform ->
+    Effect.after effect \result ->
+        when result is
+            Ok a -> transform a
+            Err err -> Task.fail err
+
+map : Task a err, (a -> b) -> Task b err
+map = \effect, transform ->
+    Effect.after effect \result ->
+        when result is
+            Ok a -> Task.succeed (transform a)
+            Err err -> Task.fail err
+
+putLine : Str -> Task {} *
+putLine = \line -> Effect.map (Effect.putLine line) (\_ -> Ok {})

examples/cli/platform/host.c

@@ -0,0 +1,7 @@
+#include <stdio.h>
+
+extern int rust_main();
+
+int main() {
+  return rust_main();
+}

examples/cli/platform/src/lib.rs

@@ -0,0 +1,133 @@
+#![allow(non_snake_case)]
+
+use roc_std::alloca;
+use roc_std::RocCallResult;
+use roc_std::RocStr;
+use std::alloc::Layout;
+use std::time::SystemTime;
+
+extern "C" {
+    #[link_name = "roc__mainForHost_1_exposed"]
+    fn roc_main(output: *mut u8) -> ();
+
+    #[link_name = "roc__mainForHost_1_size"]
+    fn roc_main_size() -> i64;
+
+    #[link_name = "roc__mainForHost_1_Fx_caller"]
+    fn call_Fx(
+        flags: &(),
+        function_pointer: *const u8,
+        closure_data: *const u8,
+        output: *mut u8,
+    ) -> ();
+
+    #[link_name = "roc__mainForHost_1_Fx_size"]
+    fn size_Fx() -> i64;
+
+    #[link_name = "roc__mainForHost_1_Fx_result_size"]
+    fn size_Fx_result() -> i64;
+}
+
+#[no_mangle]
+pub fn roc_fx_putChar(foo: i64) -> () {
+    let character = foo as u8 as char;
+    print!("{}", character);
+
+    ()
+}
+
+#[no_mangle]
+pub fn roc_fx_putLine(line: RocStr) -> () {
+    let bytes = line.as_slice();
+    let string = unsafe { std::str::from_utf8_unchecked(bytes) };
+    println!("{}", string);
+
+    ()
+}
+
+#[no_mangle]
+pub fn roc_fx_getLine() -> RocStr {
+    use std::io::{self, BufRead};
+
+    let stdin = io::stdin();
+    let line1 = stdin.lock().lines().next().unwrap().unwrap();
+
+    RocStr::from_slice(line1.as_bytes())
+}
+
+unsafe fn call_the_closure(function_pointer: *const u8, closure_data_ptr: *const u8) -> i64 {
+    let size = size_Fx_result() as usize;
+
+    alloca::with_stack_bytes(size, |buffer| {
+        let buffer: *mut std::ffi::c_void = buffer;
+        let buffer: *mut u8 = buffer as *mut u8;
+
+        call_Fx(
+            &(),
+            function_pointer,
+            closure_data_ptr as *const u8,
+            buffer as *mut u8,
+        );
+
+        let output = &*(buffer as *mut RocCallResult<()>);
+
+        match output.into() {
+            Ok(_) => 0,
+            Err(e) => panic!("failed with {}", e),
+        }
+    })
+}
+
+#[no_mangle]
+pub fn rust_main() -> isize {
+    println!("Running Roc closure");
+    let start_time = SystemTime::now();
+
+    let size = unsafe { roc_main_size() } as usize;
+    let layout = Layout::array::<u8>(size).unwrap();
+    let answer = unsafe {
+        let buffer = std::alloc::alloc(layout);
+
+        roc_main(buffer);
+
+        let output = &*(buffer as *mut RocCallResult<()>);
+
+        match output.into() {
+            Ok(()) => {
+                let function_pointer = {
+                    // this is a pointer to the location where the function pointer is stored
+                    // we pass just the function pointer
+                    let temp = buffer.offset(8) as *const i64;
+
+                    (*temp) as *const u8
+                };
+
+                let closure_data_ptr = buffer.offset(16);
+
+                let result =
+                    call_the_closure(function_pointer as *const u8, closure_data_ptr as *const u8);
+
+                std::alloc::dealloc(buffer, layout);
+
+                result
+            }
+            Err(msg) => {
+                std::alloc::dealloc(buffer, layout);
+
+                panic!("Roc failed with message: {}", msg);
+            }
+        }
+    };
+    let end_time = SystemTime::now();
+    let duration = end_time.duration_since(start_time).unwrap();
+
+    println!(
+        "Roc closure took {:.4} ms to compute this answer: {:?}",
+        duration.as_secs_f64() * 1000.0,
+        // truncate the answer, so stdout is not swamped
+        answer
+    );
+
+    // Exit code
+    0
+}

examples/task/.gitignore

@@ -0,0 +1 @@
+task-example

examples/task/Main.roc

@@ -1,12 +1,15 @@
-app "effect-example"
+app "task-example"
     packages { base: "platform" }
-    imports [ base.Task.{ Task, after }, base.File, base.Path ]
+    imports [ base.Task.{ Task }, base.File, base.Path ]
     provides [ main ] to base
 
 main : Task.Task {} (File.FileReadErr [BadUtf8])
 main =
     when Path.fromStr "Cargo.toml" is
         Ok path ->
-            Task.after (Task.putLine "Our Cargo.toml:") \_ ->
-            Task.after (File.readUtf8 path) (\line -> Task.putLine line)
+            {} <- Task.await (Task.putLine "Our Cargo.toml:")
+
+            line <- Task.await (File.readUtf8 path)
+
+            Task.putLine line
         _ -> Task.putLine "invalid path"

examples/task/platform/File.roc

@@ -2,6 +2,7 @@ interface File
     exposes [ FileReadErr, FileOpenErr, FileWriteErr, DirReadErr, readUtf8 ]
     imports [ Task.{ Task }, fx.Effect.{ after }, Path ]
 
+# TODO FIXME should be able to import this as Path.{ Path }, but there's a bug.
 Path : Path.Path
 
 # These various file errors come from the POSIX errno values - see

examples/task/platform/Pkg-Config.roc

@@ -1,5 +1,5 @@
 platform folkertdev/foo
-    requires { main : Effect {} }
+    requires { main : Task {} * }
     exposes []
     packages {}
     imports [ Task, File ]

examples/task/platform/Task.roc

@@ -1,5 +1,5 @@
 interface Task
-    exposes [ Task, succeed, fail, after, map, putLine ]
+    exposes [ Task, succeed, fail, await, map, putLine ]
     imports [ fx.Effect ]
 
 
@@ -16,8 +16,8 @@ fail = \val ->
     Effect.always (Err val)
 
 
-after : Task a err, (a -> Task b err) -> Task b err
-after = \effect, transform ->
+await : Task a err, (a -> Task b err) -> Task b err
+await = \effect, transform ->
     Effect.after effect \result ->
         when result is
             Ok a -> transform a