add initial completions on InternPool

src/analyser/completions.zig

@@ -0,0 +1,145 @@
+const std = @import("std");
+const InternPool = @import("InternPool.zig");
+const types = @import("lsp.zig");
+
+const Ast = std.zig.Ast;
+
+pub fn dotCompletions(
+    arena: std.mem.Allocator,
+    ip: *InternPool,
+    ty: InternPool.Index,
+    /// used for extracting doc comments
+    node: ?Ast.Node.Index,
+) error{OutOfMemory}![]types.CompletionItem {
+    return try dotCompletionsInternal(arena, ip, ty, node);
+}
+
+pub fn dotCompletionsInternal(
+    arena: std.mem.Allocator,
+    ip: *InternPool,
+    ty: InternPool.Index,
+    node: ?Ast.Node.Index,
+    follow_one_pointer: bool,
+) error{OutOfMemory}![]types.CompletionItem {
+    _ = node;
+
+    var completions = std.ArrayListUnmanaged(types.CompletionItem){};
+    switch (ip.indexToKey(ty)) {
+        .simple => {},
+
+        .int_type => {},
+        .pointer_type => |pointer_info| {
+            switch (pointer_info.size) {
+                .One => {
+                    try completions.append(arena, .{
+                        .label = "*",
+                        .kind = .Operator,
+                        .detail = std.fmt.allocPrint(arena, "{}", .{pointer_info.elem_type.fmtType(ip)}),
+                    });
+                    if (follow_one_pointer) {
+                        try dotCompletionsInternal(arena, ip, pointer_info.elem_type, false);
+                    }
+                },
+                .Slice => {
+                    var many_ptr_info = InternPool.Key{ .pointer_type = pointer_info };
+                    many_ptr_info.pointer_info.size = .Many;
+
+                    try completions.append(arena, .{
+                        .label = "ptr",
+                        .kind = .Field,
+                        .detail = std.fmt.allocPrint(arena, "{}", .{many_ptr_info.fmtType(ip)}),
+                    });
+                    try completions.append(arena, .{
+                        .label = "len",
+                        .kind = .Field,
+                        .detail = "usize",
+                    });
+                },
+                .Many,
+                .C,
+                => {},
+            }
+        },
+        .array_type => |array_info| {
+            try completions.append(arena, types.CompletionItem{
+                .label = "len",
+                .labelDetails = std.fmt.allocPrint(arena, "{d}", .{array_info.len}),
+                .kind = .Field,
+                .detail = "usize",
+            });
+        },
+        .struct_type => |struct_info| {
+            for (struct_info.fields) |field| {
+                try completions.append(arena, types.CompletionItem{
+                    .label = field.name,
+                    .kind = .Field,
+                    // TODO include alignment and comptime
+                    .detail = std.fmt.allocPrint(arena, "{}", .{field.ty.fmtType(ip)}),
+                });
+            }
+            // TODO namespace
+        },
+        .optional_type => |optional_info| {
+            try completions.append(arena, .{
+                .label = "?",
+                .kind = .Operator,
+                .detail = std.fmt.allocPrint(arena, "{}", .{optional_info.payload_type.fmtType(ip)}),
+            });
+        },
+        .error_union_type => {},
+        .error_set_type => |error_set_info| {
+            for (error_set_info.names) |name| {
+                try completions.append(arena, .{
+                    .label = name,
+                    .kind = .Constant,
+                    .detail = std.fmt.allocPrint(arena, "error.{s}", .{name}),
+                });
+            }
+        },
+        .enum_type => |enum_info| {
+            for (enum_info.fields) |field| {
+                try completions.append(arena, .{
+                    .label = field.name,
+                    .kind = .Field,
+                    .detail = std.fmt.allocPrint(arena, "{}", .{field.ty.fmtType(ip)}),
+                });
+            }
+            // TODO namespace
+        },
+        .function_type => {},
+        .union_type => |union_info| {
+            for (union_info.fields) |field| {
+                try completions.append(arena, .{
+                    .label = field.name,
+                    .kind = .Field,
+                    .detail = if (field.alignment != 0)
+                        std.fmt.allocPrint(arena, "align({d}) {}", .{ field.alignment, field.ty.fmtType(ip) })
+                    else
+                        std.fmt.allocPrint(arena, "{}", .{field.ty.fmtType(ip)}),
+                });
+            }
+            // TODO namespace
+        },
+        .tuple_type => {
+            // TODO
+        },
+        .vector_type => {},
+        .anyframe_type => {},
+
+        .int_u64_value,
+        .int_i64_value,
+        .int_big_value,
+        .float_16_value,
+        .float_32_value,
+        .float_64_value,
+        .float_80_value,
+        .float_128_value,
+        => {},
+
+        .bytes,
+        .aggregate,
+        .union_value,
+        => {},
+    }
+    return try completions.toOwnedSlice(arena);
+}