From fc79c23b77919f12c3f99e4ecaed832b55415bec Mon Sep 17 00:00:00 2001
From: uan <fspinardi08@gmail.com>
Date: Wed, 4 Feb 2026 18:06:51 +0100
Subject: [PATCH] boolean-type from comparisons

---
 lexer.v  | 24 ++++++++++++++++++++++--
 main.v   |  6 ++++--
 parser.v | 26 +++++++++++++++-----------
 test.one |  2 +-
 4 files changed, 42 insertions(+), 16 deletions(-)

diff --git a/lexer.v b/lexer.v
index 79790fc..5822f86 100644
--- a/lexer.v
+++ b/lexer.v
@@ -22,6 +22,10 @@ enum TokenType as u8 {
 	equals
 	less
 	greater
+	eq_eq
+	greater_eq
+	less_eq
+	not_eq
 	lparen
 	rparen
 	lsqparen
@@ -52,7 +56,7 @@ fn str_from_toktype(type TokenType) string {
 		.kw_else {'else'}
 		.kw_for {'for'}
 		.kw_break {'break'}
-		.kw_fn {'break'}
+		.kw_fn {'fn'}
 		.kw_return {'return'}
 		.identifier {'identifier'}
 		.eof {'EOF'}
@@ -74,6 +78,10 @@ fn str_from_toktype(type TokenType) string {
 		.comma {'comma'}
 		.semicolon {'semicolon'}
 		.colon {'colon'}
+		.eq_eq {'eq eq'}
+		.greater_eq {'greater eq'}
+		.less_eq {'less eq'}
+		.not_eq {'not eq'}
 	}
 }
 
@@ -96,6 +104,10 @@ fn toktype_from_delimiter(delimiter string) TokenType {
 		',' {.comma}
 		';' {.semicolon}
 		':' {.colon}
+		'==' {.eq_eq}
+    '>=' {.greater_eq}
+    '<=' {.less_eq}
+    '!=' {.not_eq}
 		else {.unknown}
 	}
 }
@@ -160,7 +172,15 @@ fn lex(input string) ?[]Token {
 		}
 		if is_delimiter(input[right], is_inside_number) && left == right {
 			if !input[right].is_space() {
-				tokens << Token{toktype_from_delimiter(input[right].ascii_str()), input[right].ascii_str()}
+				mut tok_str := input[right].ascii_str()
+					if right + 1 < input.len {
+						combined := input.substr(right, right + 2)
+						if combined in ['==', '>=', '<=', '!='] {
+							tok_str = combined
+								right++
+						}
+					}
+				tokens << Token{toktype_from_delimiter(tok_str), tok_str}
 			}
 			right++
 			left = right
diff --git a/main.v b/main.v
index 8516d44..aa8be7a 100644
--- a/main.v
+++ b/main.v
@@ -6,13 +6,15 @@ fn main() {
 	content := os.read_file("test.one") or { return }
 	println("---------\n" + content + "---------")
 	tokens := lex(content) or { return }
+	println("-- TOK --")
+	print_toks(tokens)
+
 	mut parser := Parser{
 		tokens: tokens
 		pos: 0
 	}
 	statements := parser.parse_program()
-	println("-- TOK --")
-	print_toks(tokens)
+
 	println("-- AST --")
 	println(statements)
 }
diff --git a/parser.v b/parser.v
index 33367ca..2f65d86 100644
--- a/parser.v
+++ b/parser.v
@@ -213,11 +213,9 @@ fn (mut p Parser) parse_expr() Expr {
 	mut left := p.parse_primary()
 
 	match p.peek().type {
-		.plus   {return p.parse_binary(left, '+')}
-		.minus  {return p.parse_binary(left, '-')}
-		.star   {return p.parse_binary(left, '*')}
-		.slash  {return p.parse_binary(left, '/')}
-		.equals {return p.parse_binary(left, '=')}
+		.plus, .minus, .star, .slash, .equals, .eq_eq, .not_eq, .less_eq, .greater_eq {
+			return p.parse_binary(left, p.peek().text)
+		}
 		else {return left}
 	}
 }
@@ -226,8 +224,8 @@ fn (mut p Parser) parse_binary(left Expr, op string) BinaryExpr {
 	p.next()
 	right := p.parse_expr()
 	binary_expr := BinaryExpr{left, op, right}
-	if !p.is_op_valid_for_type(p.get_expr_type(binary_expr), op) {
-		parse_error("Illegal operation ${op} for type ${p.get_expr_type(binary_expr)}")
+	if !p.is_op_valid_for_type(p.get_expr_type(left), op) {
+		parse_error("Illegal operation ${op} for type ${p.get_expr_type(left)}")
 	}
 	return binary_expr
 }
@@ -267,7 +265,11 @@ fn (mut p Parser) get_expr_type(expr Expr) string {
 			if left_t != right_t {
 				parse_error ('Type mismatch in expression: ${left_t} and ${right_t}')
 			}
-			left_t
+			if expr.op in ['<=', '==', '>=', '!='] {
+				'bool'
+			} else {
+				left_t
+			}
 		}
 		Variable {
 			p.dump_stmt()
@@ -284,12 +286,14 @@ fn (mut p Parser) get_expr_type(expr Expr) string {
 }
 
 fn (mut p Parser) is_op_valid_for_type(type string, op string) bool {
-	legal_ops := match type {
-		'int' {['+', '-', '*', '/', '<', '>', '=']}
-		'real' {['+', '-', '*', '/', '<', '>', '=']}
+	global := ['=', '==', '!=']
+	mut legal_ops := match type {
+		'int' {['+', '-', '*', '/', '<', '>', '<=', '>=',]}
+		'real' {['+', '-', '*', '/', '<', '>', '<=', '>=']}
 		'bool' {['=']}
 		else {[]}
 	}
+	legal_ops << global
 	return op in legal_ops
 }
 
diff --git a/test.one b/test.one
index dfc3894..916d105 100644
--- a/test.one
+++ b/test.one
@@ -1 +1 @@
-let a int = int((5.1 + 2.2) * 5.1);
+let a bool = 2 <= 4;