ZipponDB/src/ziql/parser/condition.zig

90 lines
3.2 KiB
Zig

const std = @import("std");
const config = @import("config");
const Allocator = std.mem.Allocator;
const Token = @import("../tokenizer.zig").Token;
const Condition = @import("../../dataStructure/filter.zig").Condition;
const printError = @import("../../utils.zig").printError;
const log = std.log.scoped(.ziqlParser);
const ZipponError = @import("error").ZipponError;
const Self = @import("../core.zig");
/// Parse to get a Condition. Which is a struct that is use by the FileEngine to retreive data.
/// In the query, it is this part name = 'Bob' or age <= 10
pub fn parseCondition(
self: Self,
allocator: Allocator,
token_ptr: *Token,
struct_name: []const u8,
) ZipponError!Condition {
var keep_next = false;
var state: Self.State = .expect_member;
var token = token_ptr.*;
var member_name: []const u8 = undefined;
var condition = Condition{};
while (state != .end) : ({
token = if (!keep_next) self.toker.next() else token;
keep_next = false;
if (config.PRINT_STATE) std.debug.print("parseCondition: {any}\n", .{state});
}) switch (state) {
.expect_member => switch (token.tag) {
.identifier => {
if (!(self.schema_engine.isMemberNameInStruct(struct_name, self.toker.getTokenSlice(token)) catch {
return printError(
"Error: Struct not found.",
ZipponError.StructNotFound,
self.toker.buffer,
token.loc.start,
token.loc.end,
);
})) {
return printError(
"Error: Member not part of struct.",
ZipponError.MemberNotFound,
self.toker.buffer,
token.loc.start,
token.loc.end,
);
}
condition.data_type = self.schema_engine.memberName2DataType(
struct_name,
self.toker.getTokenSlice(token),
) catch return ZipponError.MemberNotFound;
condition.data_index = self.schema_engine.memberName2DataIndex(
struct_name,
self.toker.getTokenSlice(token),
) catch return ZipponError.MemberNotFound;
member_name = self.toker.getTokenSlice(token);
state = .expect_operation;
},
else => return printError(
"Error: Expected member name.",
ZipponError.SynthaxError,
self.toker.buffer,
token.loc.start,
token.loc.end,
),
},
.expect_operation => {
condition.operation = try self.parseComparisonOperator(token);
state = .expect_value;
},
.expect_value => {
log.debug("Parse condition value of member {s}", .{member_name});
condition.value = try self.parseConditionValue(allocator, struct_name, member_name, condition.data_type, &token);
state = .end;
},
else => unreachable,
};
try self.checkConditionValidity(condition, token);
return condition;
}