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| author | Baitinq <manuelpalenzuelamerino@gmail.com> | 2025-01-21 00:10:04 +0100 |
|---|---|---|
| committer | Baitinq <manuelpalenzuelamerino@gmail.com> | 2025-01-21 00:10:04 +0100 |
| commit | 0ae6498192f838d091ef61c8e8518ec938cefd19 (patch) | |
| tree | 246a49681855671b9f57f85712e22fb0ad298d25 | |
| parent | Example: Add example for while loop (diff) | |
| download | interpreter-0ae6498192f838d091ef61c8e8518ec938cefd19.tar.gz interpreter-0ae6498192f838d091ef61c8e8518ec938cefd19.tar.bz2 interpreter-0ae6498192f838d091ef61c8e8518ec938cefd19.zip | |
Parser: Make additive expression left associative
| -rw-r--r-- | examples/7.src | 2 | ||||
| -rw-r--r-- | grammar.ebnf | 2 | ||||
| -rw-r--r-- | src/parser.zig | 18 |
3 files changed, 13 insertions, 9 deletions
diff --git a/examples/7.src b/examples/7.src index 3bb1b91..8e3ad60 100644 --- a/examples/7.src +++ b/examples/7.src @@ -1,7 +1,7 @@ let main = () => { let i = 4; - if i + 1 == 5 - (1 + 1) { + if i + 1 == 5 - 1 + 1 { print(i); return i; }; diff --git a/grammar.ebnf b/grammar.ebnf index bde99cb..b770797 100644 --- a/grammar.ebnf +++ b/grammar.ebnf @@ -16,7 +16,7 @@ Expression ::= EqualityExpression | AdditiveExpression | FunctionDefinition | EqualityExpression ::= AdditiveExpression "==" AdditiveExpression -AdditiveExpression ::= PrimaryExpression (("+" | "-") AdditiveExpression)? +AdditiveExpression ::= PrimaryExpression (("+" | "-") PrimaryExpression)* PrimaryExpression ::= NUMBER | BOOLEAN | IDENTIFIER | FunctionCallStatement diff --git a/src/parser.zig b/src/parser.zig index 76f2127..eead436 100644 --- a/src/parser.zig +++ b/src/parser.zig @@ -251,17 +251,21 @@ pub const Parser = struct { } }); } - // AdditiveExpression ::= PrimaryExpression (("+" | "-") AdditiveExpression)? + // AdditiveExpression ::= PrimaryExpression (("+" | "-") PrimaryExpression)* fn parse_additive_expression(self: *Parser) ParserError!*Node { errdefer if (!self.try_context) std.debug.print("Error parsing additive expression\n", .{}); - const lhs = try self.parse_primary_expression(); + var lhs = try self.parse_primary_expression(); - const plus = self.accept_token(tokenizer.TokenType.PLUS); - const minus = self.accept_token(tokenizer.TokenType.MINUS); - if (plus != null or minus != null) { - const rhs = try self.parse_additive_expression(); - return self.create_node(.{ .ADDITIVE_EXPRESSION = .{ + while (true) { + const plus = self.accept_token(tokenizer.TokenType.PLUS); + const minus = self.accept_token(tokenizer.TokenType.MINUS); + + if (plus == null and minus == null) break; + + const rhs = try self.parse_primary_expression(); + + lhs = try self.create_node(.{ .ADDITIVE_EXPRESSION = .{ .addition = plus != null, .lhs = lhs, .rhs = rhs, |