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honey/source/parser/parser.hon
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2026-08-02 20:51:39 +02:00

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import "@std"
import "@std/mem"
import "@std/arraylist"
import "@std/debug"
import "@std/enums/enummap"
import "@source/lexer"
NodeId :: distinct u32
ExtraId :: distinct NodeId
NO_ID :: maxval!(NodeId)
Diagnostic :: struct {
code ErrorCode
node NodeId
}
ParseError :: alias ErrorCode | mem.AllocError
ErrorCode :: enum {
unexpected_token,
}
ErrorDetails :: struct {
name []u8
message []u8
}
error_msg_map std.EnumMap(ErrorCode, ErrorDetails) :: enummap.init({
unexpected_token = ErrorDetails {
name = "P0",
message = "unexpected token",
},
})
hide Token :: alias lexer.Token
hide TokenId :: alias lexer.TokenId
hide TokenKind :: alias lexer.TokenKind
NodeData :: union {
node_id NodeId
extra_id ExtraId
}
Node :: struct {
kind NodeKind
main_token TokenId
data0 NodeData = NodeData{ node_id = NO_ID }
data1 NodeData = NodeData{ node_id = NO_ID }
}
NodeKind :: enum {
literal_int
literal_float
literal_string
expr_unary
expr_binary
decl
invalid
}
State :: struct {
nodes std.ArrayList(Node)
#! array of indexes into the nodes array.
extra std.ArrayList(NodeId)
next_token TokenId = TokenId(0)
}
init proc(allocator mem.Allocator) State {
return State{
nodes = arraylist.init(allocator),
extra = arraylist.init(allocator),
}
}
deinit proc(state @mut State) void {
arraylist.deinit(&state.nodes)
arraylist.deinit(&state.extra)
}
parse proc(state @mut State, tokens []Token) void ! ParseError {
_ = try parse_decl(state, tokens)
}
parse_decl proc(state @mut State, tokens []Token) NodeId ! ParseError {
# expect identifier
try expect(state, tokens, .ident)
ident_token :: state.next_token
state.next_token += 1
# expect `::` (immutable assignment)
try expect(state, tokens, .double_colon)
state.next_token += 1
# expect expression
expr :: try parse_primary(state, tokens)
# expect statement terminator (newline)
try expect_either(state, tokens, &[.newline, .eof])
state.next_token += 1
decl :: try add_node(&state.nodes, Node{
kind = .decl,
main_token = ident_token,
data0 = NodeData{ node_id = expr },
})
return decl
}
parse_primary proc(state @mut State, tokens []Token) NodeId ! mem.AllocError {
start_token :: state.next_token
state.next_token += 1
return match tokens[start_token].kind {
.int: try add_node(&state.nodes, Node{
kind = .literal_int,
main_token = start_token,
})
.float: try add_node(&state.nodes, Node{
kind = .literal_float,
main_token = start_token,
})
.string: try add_node(&state.nodes, Node{
kind = .literal_string,
main_token = start_token,
})
else: try add_node(&state.nodes, Node{
kind = .invalid,
main_token = start_token,
})
}
}
hide expect proc(state @mut State, tokens []Token, token_kind TokenKind) void ! ErrorCode {
if (tokens[state.next_token].kind != token_kind) return .unexpected_token
}
hide expect_either proc(state @mut State, tokens []Token, token_kinds []TokenKind) void ! ErrorCode {
for (token_kinds) |kind| if (tokens[state.next_token].kind == kind) return
return .unexpected_token
}
hide add_node proc(nodes @mut std.ArrayList(Node), node Node) NodeId ! mem.AllocError {
id :: node_id(nodes.items.len)
try arraylist.append(nodes, node)
return id
}
hide node_id proc(idx uint) NodeId {
debug.assert(u64(idx) < u64(NO_ID))
return NodeId(idx)
}