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honey/source/parser/parser.hon
T
2026-08-16 00:50:11 +02:00

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import "@std"
import "@std/mem"
import "@std/arraylist"
import "@std/enums/enummap"
import "@std/debug"
import "@source/lexer"
import "@source/ast"
# todo: move error stuff into a separate file
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:file Token :: alias lexer.Token
@hide:file TokenId :: alias lexer.TokenId
@hide:file TokenKind :: alias lexer.TokenKind
@hide:file Node :: alias ast.Node
@hide:file NodeId :: alias ast.NodeId
@hide:file ExtraId :: alias ast.ExtraId
@hide:file NodeData :: alias ast.NodeData
@hide:file NO_NODE :: alias ast.NO_NODE
@hide:file NO_EXTRA :: alias ast.NO_EXTRA
@hide:file token_id :: alias lexer.token_id
BindingPowerScalar :: distinct u32
BindingPower :: struct {
left BindingPowerScalar
right BindingPowerScalar
}
prefix_binding_power proc(token_kind TokenKind) ?BindingPowerScalar {
return match token_kind {
.minus: BindingPowerScalar(30)
else: null
}
}
infix_binding_power proc(token_kind TokenKind) ?BindingPower {
return match token_kind {
.plus, .minus: BindingPower{ left = BindingPowerScalar(10), right = BindingPowerScalar(11) }
.star, .slash: BindingPower{ left = BindingPowerScalar(20), right = BindingPowerScalar(21) }
else: null
}
}
postfix_binding_power proc(token_kind TokenKind) ?BindingPowerScalar {
return match token_kind {
.open_paren, .open_bracket: BindingPowerScalar(40)
else: null
}
}
State :: struct {
nodes std.ArrayList(Node)
#! array of raw u32's indexing nodes, tokens, etc.
extra std.ArrayList(u32)
tokens []Token = &[]
next_token usize = 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) NodeId ! ParseError {
state.tokens = tokens
return try parse_pkg(state)
}
parse_pkg proc(state @mut State) NodeId ! ParseError {
if (state.next_token < state.tokens.len
and state.tokens[state.next_token].kind == .eof
) return NO_NODE
stmt_ids std.ArrayList(NodeId) := arraylist.init(state.nodes.allocator)
defer arraylist.deinit(&stmt_ids)
while (state.next_token < state.tokens.len
and state.tokens[state.next_token].kind != .eof
) {
stmt_id :: try parse_decl(state)
try arraylist.append(&stmt_ids, stmt_id)
}
pkg_start :: ast.extra_id(state.extra.items.len)
for (stmt_ids.items) |stmt_id| _ = try add_extra(state, u32(stmt_id))
pkg_end :: ast.extra_id(state.extra.items.len)
return try add_node(state, Node{
kind = .package,
data0 = NodeData{ extra_id = pkg_start },
data1 = NodeData{ extra_id = pkg_end },
})
}
parse_decl proc(state @mut State) NodeId ! ParseError {
if next_n_is(state, 1, .proc)
return try parse_func_decl(state)
else
return try parse_stmt_decl(state)
}
parse_func_decl proc(state @mut State) NodeId ! ParseError {
ident_tok_id :: try consume(state, .ident)
_ = try consume(state, .proc)
_ = try consume(state, .open_paren)
param_decls std.ArrayList(NodeId) := arraylist.init(state.nodes.allocator)
defer arraylist.deinit(&param_decls)
ident_ids std.ArrayList(TokenId) := arraylist.init(state.nodes.allocator)
defer arraylist.deinit(&ident_ids)
while !next_is(state, .close_paren) {
arraylist.clear(&ident_ids)
# collect param group
while true {
param_tok_id :: try consume(state, .ident)
try arraylist.append(&ident_ids, param_tok_id)
if next_is(state, .ident) break
_ = try consume(state, .comma)
}
# collect type
try expect(state, .ident)
type_id :: try parse_primary(state)
for (ident_ids.items) |id| {
param_decl :: try add_node(state, Node{
kind = .param_decl,
main_token = id,
data0 = NodeData{ node_id = type_id },
})
try arraylist.append(&param_decls, param_decl)
}
if next_is(state, .comma) _ = try consume(state, .comma)
}
_ = try consume(state, .close_paren)
try expect(state, .ident)
return_type_id :: try parse_primary(state)
block_id :: try parse_block(state)
while next_is(state, .newline) _ = try consume(state, .newline)
extra_id :: try add_extra(state, u32(return_type_id))
_ = try add_extra(state, u32(param_decls.items.len))
for (param_decls.items) |param| _ = try add_extra(state, u32(param))
return try add_node(state, Node{
kind = .func_decl,
main_token = ident_tok_id,
data0 = NodeData{ node_id = block_id },
data1 = NodeData{ extra_id = extra_id },
})
}
parse_block proc(state @mut State) NodeId ! ParseError {
stmt_ids std.ArrayList(NodeId) := arraylist.init(state.nodes.allocator)
defer arraylist.deinit(&stmt_ids)
_ = try consume(state, .open_curly)
while next_is(state, .newline) _ = try consume(state, .newline)
while !next_is(state, .close_curly) {
stmt_id :: try parse_stmt(state)
try arraylist.append(&stmt_ids, stmt_id)
while next_is(state, .newline) _ = try consume(state, .newline)
}
_ = try consume(state, .close_curly)
block_start :: ast.extra_id(state.extra.items.len)
for (stmt_ids.items) |id| _ = try add_extra(state, u32(id))
block_end :: ast.extra_id(state.extra.items.len)
return try add_node(state, Node{
kind = .block,
data0 = NodeData{ extra_id = block_start },
data1 = NodeData{ extra_id = block_end },
})
}
parse_stmt proc(state @mut State) NodeId ! ParseError {
if next_is(state, .ident) return try parse_stmt_decl(state)
return .unexpected_token
}
parse_stmt_decl proc(state @mut State) NodeId ! ParseError {
# expect identifier
ident_tok_id :: try consume(state, .ident)
# check for type
# todo: make a parse_type proc for this
type_id :: if (next_is(state, .ident))
try parse_primary(state)
else
NO_NODE
# expect `::` or `:=` (immutable or mutable assignment)
mutability_tok_id :: try consume_either(state, &[.double_colon, .colon_equal])
# expect expression
expr_id :: try parse_expr(state)
# expect statement terminator (newline)
while (next_is(state, .newline)) _ = try consume(state, .newline)
extra_start_id :: try add_extra(state, u32(type_id))
_ = try add_extra(state, u32(expr_id))
return try add_node(state, Node{
kind = .stmt_decl,
main_token = ident_tok_id,
data0 = NodeData{ extra_id = extra_start_id },
data1 = NodeData{ token_id = mutability_tok_id },
})
}
parse_expr proc(state @mut State) NodeId ! mem.AllocError {
return try parse_expr_bp(state, BindingPowerScalar(0))
}
parse_expr_bp proc(state @mut State, min_bp BindingPowerScalar) NodeId ! mem.AllocError {
# parse left-hand side
kind := state.tokens[state.next_token].kind
lhs := if (prefix_binding_power(kind)) |right_bp| {
operator :: token_id(state.next_token)
state.next_token += 1
operand :: try parse_expr_bp(state, right_bp)
yield try add_node(state, Node{
kind = .expr_unary,
main_token = operator,
data0 = NodeData{ node_id = operand },
})
} else {
yield try parse_primary(state)
}
# parse right-hand side
while true {
kind = state.tokens[state.next_token].kind
# try postfix (higher precedence)
if postfix_binding_power(kind) |left_bp| {
if (left_bp < min_bp) break
lhs = match state.tokens[state.next_token].kind {
.open_paren: debug.unimplemented() # todo: parse call
.open_bracket: debug.unimplemented() # todo: parse index
else: unreachable
}
continue
}
# try infex (lower precedence)
if infix_binding_power(kind) |bp| {
if (bp.left < min_bp) break
operator :: token_id(state.next_token)
state.next_token += 1
rhs :: try parse_expr_bp(state, bp.right)
lhs = try add_node(state, Node{
kind = .expr_binary,
main_token = operator,
data0 = NodeData{ node_id = lhs },
data1 = NodeData{ node_id = rhs },
})
continue
}
break
}
return lhs
}
parse_primary proc(state @mut State) NodeId ! mem.AllocError {
start_idx :: state.next_token
start_tok_id :: TokenId(start_idx)
state.next_token += 1
return match state.tokens[start_idx].kind {
.int: try add_node(state, Node{
kind = .literal_int,
main_token = start_tok_id,
})
.float: try add_node(state, Node{
kind = .literal_float,
main_token = start_tok_id,
})
.string: try add_node(state, Node{
kind = .literal_string,
main_token = start_tok_id,
})
.ident: try add_node(state, Node{
kind = .expr_identifier,
main_token = start_tok_id,
})
else: try add_node(state, Node{
kind = .invalid,
main_token = start_tok_id,
})
}
}
@hide
next_is proc(state @mut State, token_kind TokenKind) bool {
return state.tokens[state.next_token].kind == token_kind
}
@hide
next_is_either proc(state @mut State, token_kinds []TokenKind) bool {
for (token_kinds) |kind| if next_is(state, kind) return true
return false
}
@hide
next_n_is proc(state @mut State, n usize, token_kind TokenKind) bool {
return state.tokens[state.next_token + n].kind == token_kind
}
@hide
expect proc(state @mut State, token_kind TokenKind) void ! ErrorCode {
if (state.tokens[state.next_token].kind != token_kind) return .unexpected_token
}
@hide
expect_either proc(state @mut State, token_kinds []TokenKind) void ! ErrorCode {
for (token_kinds) |kind| if (state.tokens[state.next_token].kind == kind) return
return .unexpected_token
}
@hide
consume proc(state @mut State, token_kind TokenKind) TokenId ! ErrorCode {
try expect(state, token_kind)
id :: TokenId(state.next_token)
state.next_token += 1
return id
}
@hide
consume_either proc(state @mut State, token_kinds []TokenKind) TokenId ! ErrorCode {
try expect_either(state, token_kinds)
id :: TokenId(state.next_token)
state.next_token += 1
return id
}
@hide
add_node proc(state @mut State, node Node) NodeId ! mem.AllocError {
id :: ast.node_id(state.nodes.items.len)
try arraylist.append(&state.nodes, node)
return id
}
@hide
add_extra proc(state @mut State, data u32) ExtraId ! mem.AllocError {
id :: ast.extra_id(state.extra.items.len)
try arraylist.append(&state.extra, data)
return id
}