1 files changed, 157 insertions, 0 deletions
diff --git a/core/flags/conversion.odin b/core/flags/conversion.odin
new file mode 100644
index 000000000..226250228
--- /dev/null
+++ b/core/flags/conversion.odin
@@ -0,0 +1,157 @@
+package flags
+
+import "base:intrinsics"
+import "base:runtime"
+import "core:fmt"
+import "core:mem"
+import "core:reflect"
+
+_, _, _, _, _ :: intrinsics, runtime, fmt, mem, reflect
+
+// Add a positional argument to a data struct, checking for specified
+// positionals first before adding it to a fallback field.
+add_positional :: proc(data: ^$T, index: int, arg: string) -> Error {
+	field, has_pos_assigned := get_field_by_pos(data, index)
+
+	if !has_pos_assigned {
+		when !intrinsics.type_has_field(T, SUBTAG_POS) {
+			return Parse_Error {
+				.Extra_Pos,
+				fmt.tprintf("got extra positional argument `%s` with nowhere to store it", arg),
+			}
+		}
+
+		// Fall back to adding it to a dynamic array named `pos`. 
+		field = reflect.struct_field_by_name(T, SUBTAG_POS)
+		assert(field.type != nil, "this should never happen")
+	}
+
+	ptr := cast(rawptr)(uintptr(data) + field.offset)
+	if !parse_and_set_pointer_by_type(ptr, arg, field.type) {
+		return Parse_Error {
+			.Bad_Type,
+			fmt.tprintf("unable to set positional %i (%s) of type %v to `%s`", index, field.name, field.type, arg),
+		}
+	}
+
+	return nil
+}
+
+// Set a `-flag` argument.
+set_flag :: proc(data: ^$T, name: string) -> Error {
+	// We make a special case for help requests.
+	switch name {
+	case HARD_CODED_HELP_FLAG:
+		fallthrough
+	case HARD_CODED_HELP_FLAG_SHORT:
+		return Help_Request{}
+	}
+
+	field := get_field_by_name(data, name) or_return
+
+	#partial switch t in field.type.variant {
+	case runtime.Type_Info_Boolean:
+		ptr := cast(^bool)(uintptr(data) + field.offset)
+		ptr^ = true
+	case:
+		return Parse_Error {
+			.Bad_Type,
+			fmt.tprintf("unable to set `%s` of type %v to true", name, field.type),
+		}
+	}
+
+	return nil
+}
+
+// Set a `-flag:option` argument.
+set_option :: proc(data: ^$T, name, option: string) -> Error {
+	field := get_field_by_name(data, name) or_return
+
+	// Guard against incorrect syntax.
+	#partial switch t in field.type.variant {
+	case runtime.Type_Info_Map:
+		return Parse_Error {
+			.Missing_Value,
+			fmt.tprintf("unable to set `%s` of type %v to `%s`, are you missing an `=`?", name, field.type, option),
+		}
+	}
+
+	ptr := rawptr(uintptr(data) + field.offset)
+	if !parse_and_set_pointer_by_type(ptr, option, field.type) {
+		return Parse_Error {
+			.Bad_Type,
+			fmt.tprintf("unable to set `%s` of type %v to `%s`", name, field.type, option),
+		}
+	}
+
+	return nil
+}
+
+// Set a `-map:key=value` argument.
+set_key_value :: proc(data: ^$T, name, key, value: string) -> Error {
+	field := get_field_by_name(data, name) or_return
+
+	#partial switch t in field.type.variant {
+	case runtime.Type_Info_Map:
+		if !reflect.is_string(t.key) {
+			return Parse_Error {
+				.Bad_Type,
+				fmt.tprintf("`%s` must be a map[string]", name),
+			}
+		}
+
+		key := key
+		key_ptr := rawptr(&key)
+		key_cstr: cstring
+		if reflect.is_cstring(t.key) {
+			key_cstr = cstring(raw_data(key))
+			key_ptr = &key_cstr
+		}
+
+		raw_map := (^runtime.Raw_Map)(uintptr(data) + field.offset)
+
+		hash := t.map_info.key_hasher(key_ptr, runtime.map_seed(raw_map^))
+
+		backing_alloc := false
+		elem_backing: []byte
+		value_ptr: rawptr
+
+		if raw_map.allocator.procedure == nil {
+			raw_map.allocator = context.allocator
+		} else {
+			value_ptr = runtime.__dynamic_map_get(raw_map,
+				t.map_info,
+				hash,
+				key_ptr,
+			)
+		}
+
+		if value_ptr == nil {
+			elem_backing = mem.alloc_bytes(t.value.size, t.value.align) or_return
+			backing_alloc = true
+			value_ptr = raw_data(elem_backing)
+		}
+
+		if !parse_and_set_pointer_by_type(value_ptr, value, t.value) {
+			break
+		}
+
+		if backing_alloc {
+			runtime.__dynamic_map_set(raw_map,
+				t.map_info,
+				hash,
+				key_ptr,
+				value_ptr,
+			)
+
+			delete(elem_backing)
+		}
+
+		return nil
+	}
+
+	return Parse_Error {
+		.Bad_Type,
+		fmt.tprintf("unable to set `%s` of type %v with key=value `%s` = `%s`", name, field.type, key, value),
+	}
+}