FnDecl, Return, statement block

vlib/compiler/parser.v

@@ -793,13 +793,13 @@ fn (p mut Parser) type_decl() {
 	if p.tok == .key_struct {
 		p.error('use `struct $name {` instead of `type $name struct {`')
 	}
-	if p.tok == .assign {
+	is_sum := p.tok == .assign
+	if is_sum {
 		p.next()
-
 	}
-	parent := p.get_type2()
+	mut parent := Type{}
 	// Sum type
-	is_sum := p.tok == .pipe
+	//is_sum := p.tok == .pipe
 	if is_sum {
 		if !p.builtin_mod && p.mod != 'main' {
 			name = p.prepend_mod(name)
@@ -815,10 +815,15 @@ fn (p mut Parser) type_decl() {
 		*/
 		// Register the rest of them
 		mut idx := 0
-		for p.tok == .pipe {
+		mut done := false
+		for  {//p.tok == .pipe {
 			idx++
-			p.next()
+			//p.next()
 			child_type_name := p.check_name()
+			//println('$idx $child_type_name')
+			if p.tok != .pipe {
+				done = true
+			}
 			if p.pass == .main {
 				// Update the type's parent
 				//println('child=$child_type_name parent=$name')
@@ -830,13 +835,17 @@ fn (p mut Parser) type_decl() {
 				p.table.rewrite_type(t)
 				p.cgen.consts << '#define SumType_$child_type_name $idx // DEF2'
 			}
+			if done {
+				break
+			}
+			p.check(.pipe)
 		}
 		if p.pass == .decl {
 			p.table.sum_types << name
 			println(p.table.sum_types)
 		}
 		// Register the actual sum type
-		//println('registering sum $name')
+		println('registering sum $name')
 		p.table.register_type(Type{
 			name: name
 			mod: p.mod
@@ -849,6 +858,10 @@ int typ;
 } $name;
 ')
 	}
+	else {
+
+		parent = p.get_type2()
+	}
 	nt_pair := p.table.cgen_name_type_pair(name, parent.name)
 	// TODO dirty C typedef hacks for DOOM
 	// Unknown type probably means it's a struct, and it's used before the struct is defined,

vlib/v/ast/ast.v

@@ -11,10 +11,12 @@ import (
 
 struct Foo {}
 
-pub type Expr = Foo | IfExpr | BinaryExpr | UnaryExpr |
-	StringLiteral  | IntegerLiteral | FloatLiteral  | VarDecl
+pub type Expr = BinaryExpr | UnaryExpr | IfExpr |
+	StringLiteral  | IntegerLiteral | FloatLiteral  | VarDecl |
+	FnDecl | Return
+
+pub type Stmt = Foo//VarDecl
 
-pub type Stmt = Foo | Foo //VarDecl
 
 pub struct IntegerLiteral {
 pub:
@@ -32,6 +34,20 @@ pub:
 	val string
 }
 
+pub struct FnDecl {
+pub:
+	name  string
+	//stmts []Stmt
+	exprs []Expr
+	typ types.Type
+
+}
+
+pub struct Return {
+pub:
+	expr Expr
+}
+
 /*
 pub enum Expr {
 	Binary(BinaryExpr)

vlib/v/cgen/cgen.v

@@ -31,16 +31,6 @@ pub fn (g mut Gen) writeln(s string) {
 	g.out.writeln(s)
 }
 
-struct Type {
-	name string
-}
-
-const (
-	string_type = Type{'string'}
-	int_type = Type{'int'}
-	void_type = Type{'void'}
-)
-
 fn (g mut Gen) expr(node ast.Expr) {
 	//println('cgen expr()')
 	match node {
@@ -57,6 +47,18 @@ fn (g mut Gen) expr(node ast.Expr) {
 		ast.StringLiteral {
 			g.write('tos3("$it.val")')
 		}
+		ast.FnDecl {
+			g.writeln('$it.typ.name $it.name () { ')
+			for expr in it.exprs {
+				g.expr(expr)
+			}
+			g.writeln('}')
+		}
+		ast.Return {
+			g.write('return ')
+			g.expr(it.expr)
+			g.writeln(';')
+		}
 		ast.BinaryExpr {
 			g.expr(it.left)
 			match it.op {

vlib/v/parser/parser.v

@@ -18,6 +18,7 @@ mut:
 	lit     string
 	//vars []string
 	table &table.Table
+	return_type types.Type
 }
 
 pub fn parse_expr(text string, table &table.Table) ast.Expr {
@@ -33,6 +34,20 @@ pub fn parse_expr(text string, table &table.Table) ast.Expr {
 	return expr
 }
 
+pub fn (p mut Parser) get_type() types.Type {
+	defer {
+	p.next()
+	}
+	if p.lit == 'int' { return types.int_type }
+	else if p.lit == 'string' { return types.string_type }
+	else if p.lit == 'f64' { return types.f64_type }
+	else {
+		verror('bad type lit')
+		exit(1)
+	}
+
+}
+
 pub fn parse_file(text string, table &table.Table) ast.Program {
 	s := scanner.new_scanner(text)
 	mut exprs := []ast.Expr
@@ -57,6 +72,24 @@ pub fn parse_file(text string, table &table.Table) ast.Program {
 	return ast.Program{exprs}
 }
 
+pub fn (p mut Parser)  parse_block() []ast.Expr {
+	mut exprs := []ast.Expr
+
+	for {
+		//res := s.scan()
+		if p.tok == .eof || p.tok == .rcbr {
+			break
+		}
+		//println('expr at ' + p.tok.str())
+		expr,_ := p.expr(token.lowest_prec)
+		exprs << expr
+	}
+	p.next()
+	println('nr exprs in block = $exprs.len')
+	return exprs
+
+}
+
 /*
 pub fn parse_stmt(text string) ast.Stmt {
 	mut s := scanner.new_scanner(text)
@@ -78,12 +111,59 @@ fn (p mut Parser) next() {
 	p.lit = res.lit
 }
 
+fn (p mut Parser) check(expected token.Token) {
+	if p.tok != expected {
+		s := 'syntax error: unexpected `${p.tok.str()}`, expecting `${expected.str()}`'
+		verror(s)
+	}
+	p.next()
+}
+
+fn (p mut Parser) check_name() string {
+	name := p.lit
+	p.check(.name)
+	return name
+}
+
 // Implementation of Pratt Precedence
 pub fn (p mut Parser) expr(rbp int) (ast.Expr,types.Type) {
 	// null denotation (prefix)
 	tok := p.tok
 	lit := p.lit
+	if p.tok == .key_fn {
+		p.next()
+		name := p.lit
+		println('fn decl $name')
+		p.check(.name)
+		p.check(.lpar)
+		p.check(.rpar)
+		// Return type
+		mut typ := types.void_type
 		if p.tok == .name {
+			typ = p.get_type()
+			p.return_type = typ
+
+		}
+		p.check(.lcbr)
+		//p.check(.rcbr)
+		println('OK!')
+		exprs := p.parse_block()
+
+		mut node := ast.Expr{}
+		node = ast.FnDecl{name: name, exprs: exprs, typ: typ}
+		return node, types.void_type
+	}
+	else if p.tok == .key_return {
+		p.next()
+		mut node := ast.Expr{}
+		expr, typ := p.expr(0)
+		if !types.check(p.return_type, typ) {
+			verror('bad ret type')
+		}
+		node = ast.Return{expr: expr}
+		return node, types.void_type
+	}
+	else if p.tok == .name {
 		name := p.lit
 		p.next()
 		if p.tok == .decl_assign {
@@ -117,16 +197,14 @@ pub fn (p mut Parser) expr(rbp int) (ast.Expr,types.Type) {
 			}
 			p.next()
 		}
-		else {
-			// TODO: fix bug. note odd conditon instead of else if (same below)
-			if tok.is_scalar() {
-				if tok == .str {
+		.str {
 			node = ast.StringLiteral{
 				val: lit
 			}
 			typ = types.string_type
+
 		}
-				if tok == .number {
+		.number {
 			if lit.contains('.') {
 				node = ast.FloatLiteral{
 					//val: lit.f64()
@@ -140,11 +218,9 @@ pub fn (p mut Parser) expr(rbp int) (ast.Expr,types.Type) {
 				typ = types.int_type
 			}
 		}
-				// else {
-				// verror('bad scalar token')
-				// }
-			}
-			if !tok.is_scalar() && tok.is_unary() {
+		else {
+			// TODO: fix bug. note odd conditon instead of else if (same below)
+			if tok.is_unary() {
 				expr,_ := p.expr(token.highest_prec)
 				node = ast.UnaryExpr{
 					// left: p.expr(token.highest_prec)

vlib/v/parser/parser_test.v

@@ -7,10 +7,16 @@ import (
 )
 
 fn test_parse_file() {
-	s := '12 + 3
-	x := 10
-	5+7
-	8+4
+	s := '
+fn foo() string {
+	f := 23
+	return 10+4
+}
+
+12 + 3
+x := 10
+5+7
+8+4
 '
 	table := &table.Table{}
 	prog := parse_file(s, table)
@@ -20,6 +26,7 @@ fn test_parse_file() {
 
 
 fn test_parse_expr() {
+	//if true { return }
 	input := [
 		'2 + 3',
 		'2+2*4',

vlib/v/token/token.v

@@ -287,19 +287,20 @@ fn (t []Token) contains(val Token) bool {
 }
 
 pub fn (t Token) str() string {
-	lit := 't.lit'
 	if t == .number {
 		return 'number'
 	}
 	if t == .chartoken {
-		return '`lit`'
+		return 'char'//'`lit`'
 	}
 	if t == .str {
-		return "'lit'"
+		return 'str' //"'lit'"
 	}
+	/*
 	if t < .plus {
 		return lit // string, number etc
 	}
+	*/
 	return token_str[int(t)]
 }
 

vlib/v/types/types.v

@@ -13,6 +13,7 @@ pub const (
 	void_type = Type{'void', 0}
 	int_type = Type{'int', 1}
 	string_type = Type{'string', 2}
+	f64_type = Type{'f64', 3}
 )