fix type-to-string conv. + fix binary type check + add modulo + rework import (now include)

bad.ang

@@ -1,40 +0,0 @@
-import "lib/math.ang"
-
-primes := [2]
-
-func is_prime(x: number) boolean {
-    i := 0
-    while i < primes.length() && primes.at(i)*primes.at(i) < x {
-        if mod(x, primes.at(i)) == 0 {
-            return false
-        }
-        i = i + 1
-    }
-
-    return true
-}
-
-n := 1
-max := 100000
-
-while n < max {
-    n = n + 2
-
-    if is_prime(n) {
-        primes.append(n)
-
-        # Update counter
-        print(char(0x0D))
-        print(str(n))
-        print("/")
-        print(str(max))
-        print(char(0x09))
-        print(str(roundd(n/max*100, 2)))
-        print("%")
-        print(char(0x09))
-        print(str(primes.length()))
-        print(" primes")
-    }
-}
-
-write(str(primes))

chars.ang

@@ -1,15 +0,0 @@
-
-MAX_WIDTH := 16
-
-print(" ")
-w := 1
-n := 0x21
-while n < 0xA0 {
-    print(char(n))
-    n = n + 1
-    w = w + 1
-    if w >= MAX_WIDTH {
-        write("")
-        w = 0
-    }
-}

cli/main.go

@@ -150,7 +150,8 @@ func makeChunk(ctx *Context, fpath string, ignoreWarnings bool) (*core.Chunk, er
 	if ctx.Debug {
 		log.Println("Compiling parse tree")
 	}
-	err = c.Compile(tree)
+
+	_, err = c.Compile(tree)
 	if err != nil {
 		var e core.FormatedError
 		if errors.As(err, &e) {
@@ -296,7 +297,7 @@ func (cmd *ReplCmd) Run(ctx *Context) error {
 		}
 
 		c.SetSource(src)
-		if err = c.Compile(prog); err != nil {
+		if _, err = c.Compile(prog); err != nil {
 			var e core.FormatedError
 			if errors.As(err, &e) {
 				log.Print(e.Format())

codegen.ang

@@ -1,24 +0,0 @@
-
-passphrase := "Hello world!".split("")
-start := [0, 0, 0]
-modulus := 10
-base := byte("!")
-
-i := 0
-n := 0
-while n < passphrase.length() {
-    b := byte(passphrase.at(n))
-
-    v = start.at(i) + b - base
-    while v >= modulus {
-        v = v - modulus
-    }
-
-    start.put(i, v)
-
-    if i >= 3 {
-        i = 0
-    }
-    n = n + 1
-}
-

core/lexer.go

@@ -7,24 +7,29 @@ import (
 )
 
 type Token struct {
-	Type   TokenType
+	Type   TokenKind
 	Start  Pos
 	End    Pos
 	Line   Pos
 	Lexeme string
 }
 
+func (t Token) Bounds() (Pos, Pos) {
+	return t.Start, t.End
+}
+
 func (t Token) String() string {
 	return fmt.Sprintf("token %s, '%s' %d -> %d, line %d", t.Type.String(), t.Lexeme, t.Start, t.End, t.Line)
 }
 
-type TokenType uint64
+type TokenKind uint64
 
 const (
-	TokenPlus TokenType = iota
+	TokenPlus TokenKind = iota
 	TokenMinus
 	TokenStar
 	TokenSlash
+	TokenPercent
 	TokenBang
 	TokenSemicolon
 
@@ -51,7 +56,10 @@ const (
 	TokenVar
 	TokenIf
 	TokenElse
-	TokenImport
+	TokenInclude
+	TokenType
+	TokenFor
+	TokenIn
 
 	TokenComma
 	TokenDot
@@ -77,7 +85,7 @@ const (
 	TokenError
 )
 
-func (t TokenType) String() string {
+func (t TokenKind) String() string {
 	switch t {
 	case TokenPlus:
 		return "plus"
@@ -159,8 +167,8 @@ func (t TokenType) String() string {
 		return "open bracket"
 	case TokenCloseBracket:
 		return "close bracket"
-	case TokenImport:
-		return "import"
+	case TokenInclude:
+		return "include"
 	case TokenColon:
 		return "colon"
 	case TokenPipe:
@@ -171,11 +179,34 @@ func (t TokenType) String() string {
 		return "arrow"
 	case TokenNewLine:
 		return "newline"
+	case TokenType:
+		return "type"
+	case TokenFor:
+		return "for"
+	case TokenIn:
+		return "in"
 	}
 
 	panic("UNDEFINED TOKENTYPE STRING CONVERSION")
 }
 
+var Keywords = map[string]TokenKind{
+	"true":       TokenTrue,
+	"false":      TokenFalse,
+	"nil":        TokenNil,
+	"if":         TokenIf,
+	"else":       TokenElse,
+	"include":    TokenInclude,
+	"var":        TokenVar,
+	"fn":         TokenFunc,
+	"return":     TokenReturn,
+	"while":      TokenWhile,
+	"breakpoint": TokenBreakpoint,
+	"type":       TokenType,
+	"for":        TokenFor,
+	"in":         TokenIn,
+}
+
 type Lexer struct {
 	src     []rune
 	start   Pos
@@ -238,6 +269,8 @@ func (l *Lexer) NextToken() (Token, error) {
 		}
 
 		return l.makeToken(TokenSlash), nil
+	case '%':
+		return l.makeToken(TokenPercent), nil
 	case '(':
 		return l.makeToken(TokenOpenParenthesis), nil
 	case ')':
@@ -340,32 +373,12 @@ func (l *Lexer) NextToken() (Token, error) {
 				l.advance()
 			}
 
-			switch string(l.src[l.start:l.current]) {
-			case "true":
-				return l.makeToken(TokenTrue), nil
-			case "false":
-				return l.makeToken(TokenFalse), nil
-			case "nil":
-				return l.makeToken(TokenNil), nil
-			case "if":
-				return l.makeToken(TokenIf), nil
-			case "else":
-				return l.makeToken(TokenElse), nil
-			case "var":
-				return l.makeToken(TokenVar), nil
-			case "fn":
-				return l.makeToken(TokenFunc), nil
-			case "while":
-				return l.makeToken(TokenWhile), nil
-			case "breakpoint":
-				return l.makeToken(TokenBreakpoint), nil
-			case "return":
-				return l.makeToken(TokenReturn), nil
-			case "import":
-				return l.makeToken(TokenImport), nil
-			default:
-				return l.makeToken(TokenName), nil
+			lexeme := string(l.src[l.start:l.current])
+			if k, ok := Keywords[lexeme]; ok {
+				return l.makeToken(k), nil
 			}
+
+			return l.makeToken(TokenName), nil
 		} else if c == '0' && l.peek() != '.' {
 			if l.peek() == 'x' {
 				l.advance()
@@ -400,7 +413,7 @@ func (l *Lexer) NextToken() (Token, error) {
 	}
 }
 
-func NewToken(t TokenType, start Pos, end Pos, line Pos, lexeme string) Token {
+func NewToken(t TokenKind, start Pos, end Pos, line Pos, lexeme string) Token {
 	return Token{
 		Type:   t,
 		Start:  start,
@@ -425,7 +438,7 @@ func (l *Lexer) Tokenize() ([]Token, error) {
 	return tokens, err
 }
 
-func (l *Lexer) makeToken(t TokenType) Token {
+func (l *Lexer) makeToken(t TokenKind) Token {
 	return NewToken(t, l.start, l.current, l.line, string(l.src[l.start:l.current]))
 }
 

core/lexer_test.go

@@ -6,37 +6,37 @@ import (
 
 type LexerTestData struct {
 	source         string
-	expectedTokens []TokenType
+	expectedTokens []TokenKind
 }
 
 func GetLexerTestData() map[string]LexerTestData {
 	return map[string]LexerTestData{
 		"hello_world_string(1)": {
 			"\"Hello world\"",
-			[]TokenType{TokenString, TokenEOF},
+			[]TokenKind{TokenString, TokenEOF},
 		},
 		"empty_string(1)": {
 			"\"\"",
-			[]TokenType{TokenString, TokenEOF},
+			[]TokenKind{TokenString, TokenEOF},
 		},
 		"simple number(1)": {
 			"1024",
-			[]TokenType{TokenInteger, TokenEOF},
+			[]TokenKind{TokenInteger, TokenEOF},
 		},
 		"simple_arithmetics(7)": {
 			"1 + 23 / 4 * 3",
-			[]TokenType{
+			[]TokenKind{
 				TokenInteger, TokenPlus, TokenInteger, TokenSlash,
 				TokenInteger, TokenStar, TokenInteger, TokenEOF,
 			},
 		},
 		"condition(3)": {
 			"a <= 200",
-			[]TokenType{TokenName, TokenLessThanOrEqual, TokenInteger, TokenEOF},
+			[]TokenKind{TokenName, TokenLessThanOrEqual, TokenInteger, TokenEOF},
 		},
 		"if_statement(10)": {
 			"if a >= 200 {\n    write(\"Hello world!\")\n}",
-			[]TokenType{
+			[]TokenKind{
 				TokenIf, TokenName, TokenGreaterThanOrEqual, TokenInteger, TokenOpenBrace, TokenNewLine,
 				TokenName, TokenOpenParenthesis, TokenString, TokenCloseParenthesis, TokenNewLine,
 				TokenCloseBrace, TokenEOF,
@@ -44,7 +44,7 @@ func GetLexerTestData() map[string]LexerTestData {
 		},
 		"if_else_statement(20)": {
 			"if 23 * 2/3 > 32 {\n    write(\"It is larger!\")\n} else {\n    write(\"It is lower!\")\n}",
-			[]TokenType{
+			[]TokenKind{
 				TokenIf, TokenInteger, TokenStar, TokenInteger, TokenSlash, TokenInteger, TokenGreaterThan, TokenInteger, TokenOpenBrace, TokenNewLine,
 				TokenName, TokenOpenParenthesis, TokenString, TokenCloseParenthesis, TokenNewLine, TokenCloseBrace,
 				TokenElse, TokenOpenBrace, TokenNewLine, TokenName, TokenOpenParenthesis, TokenString, TokenCloseParenthesis, TokenNewLine, TokenCloseBrace,
@@ -53,11 +53,11 @@ func GetLexerTestData() map[string]LexerTestData {
 		},
 		"empty_string": {
 			"",
-			[]TokenType{TokenEOF},
+			[]TokenKind{TokenEOF},
 		},
 		"full_arithmetic_equality": {
 			"a + 2 == 10 * 2 / 3",
-			[]TokenType{
+			[]TokenKind{
 				TokenName, TokenPlus, TokenInteger, TokenEquals,
 				TokenInteger, TokenStar, TokenInteger, TokenSlash, TokenInteger,
 				TokenEOF,
@@ -65,11 +65,11 @@ func GetLexerTestData() map[string]LexerTestData {
 		},
 		"name": {
 			"print",
-			[]TokenType{TokenName, TokenEOF},
+			[]TokenKind{TokenName, TokenEOF},
 		},
 		"bunch_of_parentheses": {
 			"(((())))",
-			[]TokenType{
+			[]TokenKind{
 				TokenOpenParenthesis, TokenOpenParenthesis, TokenOpenParenthesis, TokenOpenParenthesis,
 				TokenCloseParenthesis, TokenCloseParenthesis, TokenCloseParenthesis, TokenCloseParenthesis,
 				TokenEOF,
@@ -77,22 +77,22 @@ func GetLexerTestData() map[string]LexerTestData {
 		},
 		"space_before_string": {
 			"\n   	\"\"",
-			[]TokenType{TokenNewLine, TokenString, TokenEOF},
+			[]TokenKind{TokenNewLine, TokenString, TokenEOF},
 		},
 		"write_call": {
 			"write(\"Hello world\")",
-			[]TokenType{TokenName, TokenOpenParenthesis, TokenString, TokenCloseParenthesis, TokenEOF},
+			[]TokenKind{TokenName, TokenOpenParenthesis, TokenString, TokenCloseParenthesis, TokenEOF},
 		},
 		"complex_comparison": {
 			"!(h__elo123  >= 1)",
-			[]TokenType{
+			[]TokenKind{
 				TokenBang, TokenOpenParenthesis, TokenName, TokenGreaterThanOrEqual, TokenInteger, TokenCloseParenthesis,
 				TokenEOF,
 			},
 		},
 		"3assignments_1condition": {
 			"a = 8 * 32\nb = a > 256\nc = a <= 256\n!b == c",
-			[]TokenType{
+			[]TokenKind{
 				TokenName, TokenAssign, TokenInteger, TokenStar, TokenInteger, TokenNewLine,
 				TokenName, TokenAssign, TokenName, TokenGreaterThan, TokenInteger, TokenNewLine,
 				TokenName, TokenAssign, TokenName, TokenLessThanOrEqual, TokenInteger, TokenNewLine,
@@ -101,14 +101,14 @@ func GetLexerTestData() map[string]LexerTestData {
 		},
 		"function": {
 			"fn sum(a, b) {\n    return a + b\n}",
-			[]TokenType{
+			[]TokenKind{
 				TokenFunc, TokenName, TokenOpenParenthesis, TokenName, TokenComma, TokenName, TokenCloseParenthesis,
 				TokenOpenBrace, TokenNewLine, TokenReturn, TokenName, TokenPlus, TokenName, TokenNewLine, TokenCloseBrace,
 			},
 		},
 		"while_loop": {
 			"while a < 5 {\n    a = a + 1\n}",
-			[]TokenType{
+			[]TokenKind{
 				TokenWhile, TokenName, TokenLessThan, TokenInteger, TokenOpenBrace, TokenNewLine,
 				TokenName, TokenAssign, TokenName, TokenPlus, TokenInteger, TokenNewLine, TokenCloseBrace, TokenEOF,
 			},
@@ -117,14 +117,14 @@ func GetLexerTestData() map[string]LexerTestData {
 			"sum := fn(a, b) {\n" +
 				"    return a + b\n" +
 				"}",
-			[]TokenType{
+			[]TokenKind{
 				TokenName, TokenDeclare, TokenFunc, TokenOpenParenthesis, TokenName, TokenComma, TokenName, TokenCloseParenthesis,
 				TokenOpenBrace, TokenNewLine, TokenReturn, TokenName, TokenPlus, TokenName, TokenNewLine, TokenCloseBrace,
 			},
 		},
 		"list": {
 			"data := [3, 1, 4, 1]",
-			[]TokenType{
+			[]TokenKind{
 				TokenName, TokenDeclare, TokenOpenBracket, TokenInteger, TokenComma, TokenInteger, TokenComma, TokenInteger, TokenComma, TokenInteger, TokenCloseBracket,
 			},
 		},

core/nodes.go

@@ -16,7 +16,7 @@ type Node interface {
 	Bounds() (Pos, Pos)
 }
 
-type Boundary interface {
+type Bounded interface {
 	Bounds() (Pos, Pos)
 }
 
@@ -34,12 +34,16 @@ const (
 	BlockNodeType
 	ConditionalNodeType
 	LoopNodeType
+	ForNodeType
 	AssignNodeType
 	InvokeNodeType
 	CallNodeType
 	FunctionNodeType
 	ReturnNodeType
 	AccessNodeType
+	AliasNodeType
+	IndexNodeType
+	IncludeNodeType
 	BreakpointNodeType
 )
 
@@ -68,7 +72,7 @@ func (n NodeType) String() string {
 	case AssignNodeType:
 		return "Assign"
 	case InvokeNodeType:
-		return "Call"
+		return "Invoke"
 	case FunctionNodeType:
 		return "Function"
 	case ReturnNodeType:
@@ -85,6 +89,10 @@ func (n NodeType) String() string {
 		return "Unary"
 	case CallNodeType:
 		return "Call"
+	case AliasNodeType:
+		return "Alias"
+	case IndexNodeType:
+		return "Index"
 	}
 	return "Invalid Node Type"
 }
@@ -231,7 +239,7 @@ func (n TupleNode) Bounds() (Pos, Pos) {
 
 type AccessNode struct {
 	source   Node
-	property string
+	property *Token
 
 	start Pos
 	end   Pos
@@ -242,7 +250,7 @@ func (n AccessNode) Type() NodeType {
 }
 
 func (n AccessNode) String() string {
-	return fmt.Sprintf("(%s from %s)", n.property, n.source)
+	return fmt.Sprintf("(%s from %s)", n.property.Lexeme, n.source)
 }
 
 func (n AccessNode) Bounds() (Pos, Pos) {
@@ -273,9 +281,9 @@ func (n BinaryOperation) String() string {
 		return "less or equal"
 	case BinaryGreaterEqual:
 		return "greater or equal"
-	case BinaryAnd:
+	case BinaryBooleanAnd:
 		return "and"
-	case BinaryOr:
+	case BinaryBooleanOr:
 		return "or"
 	}
 
@@ -287,9 +295,10 @@ const (
 	BinarySubtraction
 	BinaryMultiplication
 	BinaryDivision
+	BinaryModulo
 
-	BinaryAnd
-	BinaryOr
+	BinaryBooleanAnd
+	BinaryBooleanOr
 
 	// Comparison
 	BinaryEquality
@@ -310,6 +319,8 @@ func (n BinaryOperation) Symbol() string {
 		return "*"
 	case BinaryDivision:
 		return "/"
+	case BinaryModulo:
+		return "%"
 	case BinaryEquality:
 		return "=="
 	case BinaryInequality:
@@ -322,9 +333,9 @@ func (n BinaryOperation) Symbol() string {
 		return "<="
 	case BinaryGreaterEqual:
 		return ">="
-	case BinaryAnd:
+	case BinaryBooleanAnd:
 		return "&&"
-	case BinaryOr:
+	case BinaryBooleanOr:
 		return "||"
 	}
 
@@ -337,6 +348,7 @@ type BinaryNode struct {
 	Left  Node
 	Right Node
 
+	operator *Token
 	start    Pos
 	end      Pos
 }
@@ -386,6 +398,7 @@ type UnaryNode struct {
 	UnaryOperation
 	value Node
 
+	operator *Token
 	start    Pos
 	end      Pos
 }
@@ -404,7 +417,7 @@ func (n UnaryNode) Bounds() (Pos, Pos) {
 
 // BooleanNode boolean value
 type BooleanNode struct {
-	value bool
+	Boolean bool
 
 	start Pos
 	end   Pos
@@ -415,7 +428,7 @@ func (n BooleanNode) Type() NodeType {
 }
 
 func (n BooleanNode) String() string {
-	return strconv.FormatBool(n.value)
+	return strconv.FormatBool(n.Boolean)
 }
 
 func (n BooleanNode) Bounds() (Pos, Pos) {
@@ -493,7 +506,7 @@ func (n ConditionalNode) Bounds() (Pos, Pos) {
 	return n.start, n.end
 }
 
-// LoopNode Loops (for/while)
+// LoopNode While loops
 type LoopNode struct {
 	condition Node
 	do        Node
@@ -514,6 +527,28 @@ func (n LoopNode) Bounds() (Pos, Pos) {
 	return n.start, n.end
 }
 
+// ForNode For loops
+type ForNode struct {
+	counter  Node
+	iterator Node
+	logic    Node
+
+	start Pos
+	end   Pos
+}
+
+func (n ForNode) Type() NodeType {
+	return ForNodeType
+}
+
+func (n ForNode) String() string {
+	return fmt.Sprintf("for %s in %s; %s", n.counter, n.iterator, n.logic)
+}
+
+func (n ForNode) Bounds() (Pos, Pos) {
+	return n.start, n.end
+}
+
 // AssignNode assignment
 type AssignNode struct {
 	dest    Node
@@ -560,7 +595,7 @@ func (n InvokeNode) Bounds() (Pos, Pos) {
 // CallNode call a function of a value
 type CallNode struct {
 	source Node
-	name   Token
+	name   *Token
 	args   []Node
 
 	start Pos
@@ -607,6 +642,18 @@ func (n FunctionNode) Bounds() (Pos, Pos) {
 	return n.start, n.end
 }
 
+func (n FunctionNode) Signature() *FunctionSignature {
+	args := make([]TypeSignature, len(n.parameters))
+	for i, p := range n.parameters {
+		args[i] = p.Signature
+	}
+
+	return &FunctionSignature{
+		args,
+		n.yield,
+	}
+}
+
 // ReturnNode return a value out of this context
 type ReturnNode struct {
 	value Node
@@ -627,6 +674,65 @@ func (n ReturnNode) Bounds() (Pos, Pos) {
 	return n.start, n.end
 }
 
+type AliasNode struct {
+	name      *Token
+	signature TypeSignature
+
+	start Pos
+	end   Pos
+}
+
+func (n AliasNode) Type() NodeType {
+	return AliasNodeType
+}
+
+func (n AliasNode) String() string {
+	return fmt.Sprintf("alias %s to be %s", n.name, n.signature)
+}
+
+func (n AliasNode) Bounds() (Pos, Pos) {
+	return n.start, n.end
+}
+
+type IncludeNode struct {
+	path *StringNode
+
+	start Pos
+	end   Pos
+}
+
+func (n IncludeNode) Type() NodeType {
+	return IncludeNodeType
+}
+
+func (n IncludeNode) String() string {
+	return fmt.Sprintf("include \"%s\"", n.path)
+}
+
+func (n IncludeNode) Bounds() (Pos, Pos) {
+	return n.start, n.end
+}
+
+type IndexNode struct {
+	source Node
+	index  Node
+
+	start Pos
+	end   Pos
+}
+
+func (n IndexNode) Type() NodeType {
+	return IndexNodeType
+}
+
+func (n IndexNode) String() string {
+	return fmt.Sprintf("index %s of %s", n.source.String(), n.index)
+}
+
+func (n IndexNode) Bounds() (Pos, Pos) {
+	return n.start, n.end
+}
+
 type BreakpointNode struct {
 	start Pos
 	end   Pos

core/parser_test.go

@@ -1,9 +1,8 @@
 package core
 
 import (
-	"fmt"
+	"math/big"
 	"strconv"
-	"strings"
 	"testing"
 )
 
@@ -74,6 +73,7 @@ func GetTokenTestData() map[string]TokenTestData {
 								2,
 								0, 0,
 							},
+							nil,
 							0, 0,
 						},
 						false,
@@ -129,6 +129,7 @@ func GetTokenTestData() map[string]TokenTestData {
 								"b",
 								0, 0,
 							},
+							nil,
 							0, 0,
 						},
 						true,
@@ -190,12 +191,14 @@ func GetTokenTestData() map[string]TokenTestData {
 											1,
 											0, 0,
 										},
+										nil,
 										0, 0,
 									},
 									&FloatNode{
 										5,
 										0, 0,
 									},
+									nil,
 									0, 0,
 								},
 								&BinaryNode{
@@ -214,10 +217,13 @@ func GetTokenTestData() map[string]TokenTestData {
 											2,
 											0, 0,
 										},
+										nil,
 										0, 0,
 									},
+									nil,
 									0, 0,
 								},
+								nil,
 								0, 0,
 							},
 							&BinaryNode{
@@ -230,8 +236,10 @@ func GetTokenTestData() map[string]TokenTestData {
 									2,
 									0, 0,
 								},
+								nil,
 								0, 0,
 							},
+							nil,
 							0, 0,
 						},
 						false,
@@ -264,6 +272,7 @@ func GetTokenTestData() map[string]TokenTestData {
 								15,
 								0, 0,
 							},
+							nil,
 							0, 0,
 						},
 						false,
@@ -299,6 +308,7 @@ func GetTokenTestData() map[string]TokenTestData {
 								0,
 								0, 0,
 							},
+							nil,
 							0, 0,
 						},
 						do: &BlockNode{
@@ -352,6 +362,7 @@ func GetTokenTestData() map[string]TokenTestData {
 								0,
 								0, 0,
 							},
+							nil,
 							0, 0,
 						},
 						do: &BlockNode{
@@ -459,6 +470,7 @@ func GetTokenTestData() map[string]TokenTestData {
 												"b",
 												0, 0,
 											},
+											nil,
 											0, 0,
 										},
 										0, 0,
@@ -530,6 +542,7 @@ func GetTokenTestData() map[string]TokenTestData {
 												"b",
 												0, 0,
 											},
+											nil,
 											0, 0,
 										},
 										0, 0,
@@ -565,7 +578,7 @@ func GetTokenTestData() map[string]TokenTestData {
 								"a",
 								0, 0,
 							},
-							"b",
+							&Token{TokenName, 0, 1, 0, "b"},
 							0, 0,
 						},
 						true,
@@ -651,6 +664,57 @@ func GetTokenTestData() map[string]TokenTestData {
 				0, 0,
 			},
 		},
+		"single_tuple": {
+			[]Token{
+				NewToken(TokenOpenParenthesis, 0, 0, 0, "("),
+				NewToken(TokenInteger, 0, 0, 0, "1"),
+				NewToken(TokenComma, 0, 0, 0, ","),
+				NewToken(TokenCloseParenthesis, 0, 0, 0, ")"),
+				NewToken(TokenEOF, 0, 0, 0, ""),
+			},
+			&BlockNode{
+				[]Node{
+					&TupleNode{
+						[]Node{
+							&IntegerNode{
+								big.NewInt(1),
+								0, 0,
+							},
+						},
+						0, 0,
+					},
+				},
+				0, 0,
+			},
+		},
+		"tuple": {
+			[]Token{
+				NewToken(TokenOpenParenthesis, 0, 0, 0, "("),
+				NewToken(TokenInteger, 0, 0, 0, "1"),
+				NewToken(TokenComma, 0, 0, 0, ","),
+				NewToken(TokenInteger, 0, 0, 0, "2"),
+				NewToken(TokenCloseParenthesis, 0, 0, 0, ")"),
+				NewToken(TokenEOF, 0, 0, 0, ""),
+			},
+			&BlockNode{
+				[]Node{
+					&TupleNode{
+						[]Node{
+							&IntegerNode{
+								big.NewInt(1),
+								0, 0,
+							},
+							&IntegerNode{
+								big.NewInt(2),
+								0, 0,
+							},
+						},
+						0, 0,
+					},
+				},
+				0, 0,
+			},
+		},
 	}
 }
 
@@ -717,10 +781,10 @@ func NodeEquality(t *testing.T, n1 Node, n2 Node) {
 		NodeEquality(t, n1.(*BinaryNode).Right, n2.(*BinaryNode).Right)
 
 	case BooleanNodeType:
-		if n1.(*BooleanNode).value != n2.(*BooleanNode).value {
-			t.Errorf("Boolean node values don't match (%s and %s)", strconv.FormatBool(n1.(*BooleanNode).value), strconv.FormatBool(n2.(*BooleanNode).value))
+		if n1.(*BooleanNode).Boolean != n2.(*BooleanNode).Boolean {
+			t.Errorf("Boolean node values don't match (%s and %s)", strconv.FormatBool(n1.(*BooleanNode).Boolean), strconv.FormatBool(n2.(*BooleanNode).Boolean))
 		} else {
-			t.Logf("Boolean node values match (%s)", strconv.FormatBool(n1.(*BooleanNode).value))
+			t.Logf("Boolean node values match (%s)", strconv.FormatBool(n1.(*BooleanNode).Boolean))
 		}
 	case BlockNodeType:
 		if len(n1.(*BlockNode).statements) != len(n2.(*BlockNode).statements) {
@@ -790,7 +854,7 @@ func NodeEquality(t *testing.T, n1 Node, n2 Node) {
 		}
 
 		for i, p := range m.parameters {
-			if !n.parameters[i].Signature.Matches(p.Signature) {
+			if !n.parameters[i].Signature.Contains(p.Signature) {
 				t.Errorf("Function node parameter signature %d does not match: %s and %s", i, p.Signature, n.parameters[i].Signature)
 			} else if n.parameters[i].Name != p.Name {
 				t.Errorf("Function node parameter name %d does not match: %s and %s", i, p.Name, n.parameters[i].Name)
@@ -808,10 +872,11 @@ func NodeEquality(t *testing.T, n1 Node, n2 Node) {
 		a1 := n1.(*AccessNode)
 		a2 := n2.(*AccessNode)
 
-		if a1.property != a2.property {
-			t.Errorf("Access node property does not match: .%s != .%s", a1.property, a2.property)
+		// only care about lexeme; the rest is debug info
+		if a1.property.Lexeme != a2.property.Lexeme {
+			t.Errorf("Access node property does not match: .%s != .%s", a1.property.Lexeme, a2.property.Lexeme)
 		} else {
-			t.Logf("Access node property matches: .%s", a1.property)
+			t.Logf("Access node property matches: .%s", a1.property.Lexeme)
 		}
 
 		NodeEquality(t, a1.source, a2.source)
@@ -825,7 +890,7 @@ func NodeEquality(t *testing.T, n1 Node, n2 Node) {
 			t.Logf("Both content types are yet to be determined")
 		} else if l1.content != nil || l2.content != nil {
 			t.Errorf("one is nil, one is not")
-		} else if !l1.content.Matches(l2.content) {
+		} else if !l1.content.Contains(l2.content) {
 			t.Errorf("signature doesn't match")
 		}
 
@@ -834,110 +899,24 @@ func NodeEquality(t *testing.T, n1 Node, n2 Node) {
 			NodeEquality(t, v1, l2.items[i])
 		}
 
+	case TupleNodeType:
+		t1 := n1.(*TupleNode)
+		t2 := n2.(*TupleNode)
+
+		if len(t1.items) != len(t2.items) {
+			t.Fatalf("tuple item count does not match")
+		}
+
+		for i, v1 := range t1.items {
+			t.Logf("Checking item %d", i)
+			NodeEquality(t, v1, t2.items[i])
+		}
+
 	default:
 		panic("unimplemented node equality")
 	}
 }
 
-func SerializeTokens(tokens []Token) string {
-	out := strings.Builder{}
-	level := 0
-
-	for _, token := range tokens {
-		switch token.Type {
-		case TokenPlus:
-			out.WriteString(" + ")
-		case TokenMinus:
-			out.WriteString(" - ")
-		case TokenStar:
-			out.WriteString("*")
-		case TokenSlash:
-			out.WriteString("/")
-		case TokenBang:
-			out.WriteString("!")
-		case TokenSemicolon:
-			out.WriteString(";")
-		case TokenFloat:
-			out.WriteString(token.Lexeme)
-		case TokenString:
-			out.WriteString(fmt.Sprintf("\"%s\"", token.Lexeme))
-		case TokenName:
-			out.WriteString(token.Lexeme)
-		case TokenOpenParenthesis:
-			out.WriteString("(")
-		case TokenCloseParenthesis:
-			out.WriteString(")")
-		case TokenOpenBracket:
-			out.WriteString("[")
-		case TokenCloseBracket:
-			out.WriteString("]")
-		case TokenOpenBrace:
-			out.WriteString("{")
-			level = level + 1
-		case TokenCloseBrace:
-			out.WriteString("}")
-			level = level - 1
-		case TokenTrue:
-			out.WriteString("true")
-		case TokenFalse:
-			out.WriteString("false")
-		case TokenNil:
-			out.WriteString("nil")
-		case TokenFunc:
-			out.WriteString("fn")
-		case TokenReturn:
-			out.WriteString("return ")
-		case TokenWhile:
-			out.WriteString("while ")
-		case TokenVar:
-			out.WriteString("var ")
-		case TokenIf:
-			out.WriteString("if ")
-		case TokenElse:
-			out.WriteString(" else ")
-		case TokenImport:
-			out.WriteString("import ")
-		case TokenComma:
-			out.WriteString(", ")
-		case TokenDot:
-			out.WriteString(".")
-		case TokenColon:
-			out.WriteString(": ")
-		case TokenAssign:
-			out.WriteString(" = ")
-		case TokenDeclare:
-			out.WriteString(" := ")
-		case TokenBangEquals:
-			out.WriteString(" != ")
-		case TokenEquals:
-			out.WriteString(" == ")
-		case TokenGreaterThan:
-			out.WriteString(" > ")
-		case TokenLessThan:
-			out.WriteString(" < ")
-		case TokenGreaterThanOrEqual:
-			out.WriteString(" >= ")
-		case TokenLessThanOrEqual:
-			out.WriteString(" <= ")
-		case TokenDoubleAmpersand:
-			out.WriteString(" && ")
-		case TokenDoublePipe:
-			out.WriteString(" || ")
-		case TokenBreakpoint:
-			out.WriteString("breakpoint")
-		case TokenEOF:
-			out.WriteString(fmt.Sprintf("<error: \"%s\">", token.Lexeme))
-		case TokenHexadecimal:
-			out.WriteString(token.Lexeme)
-		case TokenPipe:
-			out.WriteString(" | ")
-		case TokenError:
-		}
-	}
-
-	return out.String()
-}
-
 func TestParser_Parse(t *testing.T) {
 	t.Logf("Getting test data")
 	tokenData := GetTokenTestData()
@@ -960,6 +939,31 @@ func TestParser_Parse(t *testing.T) {
 	}
 }
 
+func TestParser_AcceptAll(t *testing.T) {
+	p := NewParser("a:", []string{}, []Token{
+		NewToken(TokenName, 0, 1, 0, "a"),
+		NewToken(TokenColon, 1, 2, 0, "a"),
+	})
+
+	if !p.acceptAll(TokenName, TokenColon) {
+		t.Fatalf("tokens were not accepted")
+	}
+
+	t.Logf("tokens were accepted")
+}
+
+func TestParser_AcceptAll_TooFew(t *testing.T) {
+	p := NewParser("a", []string{}, []Token{
+		NewToken(TokenName, 0, 1, 0, "a"),
+	})
+
+	if p.acceptAll(TokenName, TokenColon) {
+		t.Fatalf("tokens were incorrectly accepted")
+	}
+
+	t.Logf("tokens were, as expected, not accepted")
+}
+
 func BenchmarkParser_Parse(b *testing.B) {
 	tokenData := GetTokenTestData()
 

core/types.go

@@ -14,11 +14,13 @@ const (
 	TypeBoolean
 	TypeNil
 	TypeList
+	TypeTuple
 	TypeObject
 	TypeFunction
 	TypeAny
 	TypeComposite
 	TypeInner
+	TypeNamed
 )
 
 func (t Type) String() string {
@@ -35,6 +37,8 @@ func (t Type) String() string {
 		return "nil"
 	case TypeList:
 		return "list"
+	case TypeTuple:
+		return "tuple"
 	case TypeObject:
 		return "object"
 	case TypeFunction:
@@ -68,7 +72,7 @@ func SignatureOf(v Value) TypeSignature {
 			sig := SignatureOf(p)
 			if contains == nil {
 				contains = sig
-			} else if !contains.Matches(sig) {
+			} else if !contains.Contains(sig) {
 				contains = &AnySignature{}
 				break
 			}
@@ -92,6 +96,16 @@ func SignatureOf(v Value) TypeSignature {
 		}
 	case *BuiltinFunctionValue:
 		return t.Signature
+	case *TupleValue:
+		var contains []TypeSignature
+		for _, p := range t.Items {
+			sig := SignatureOf(p)
+			contains = append(contains, sig)
+		}
+
+		return &TupleSignature{
+			contains,
+		}
 	}
 
 	panic(fmt.Sprintf("unknown value; cannot get signature of %s", v))
@@ -100,8 +114,12 @@ func SignatureOf(v Value) TypeSignature {
 type TypeSignature interface {
 	Type() Type
 
-	// Matches check if this type signature matches another.
-	Matches(TypeSignature) bool
+	// Contains check if this type signature matches another.
+	// For it to return true, the other type should be a part of this.
+	Contains(TypeSignature) bool
+
+	// Equal check if the other signature is the EXACT SAME as this one.
+	Equal(TypeSignature) bool
 
 	// String create a human-readable string version of the value type.
 	String() string
@@ -113,12 +131,12 @@ func (*NilSignature) Type() Type {
 	return TypeNil
 }
 
-func (s *NilSignature) Matches(other TypeSignature) bool {
-	if other.Type() == TypeComposite {
-		return other.Matches(s)
+func (s *NilSignature) Contains(other TypeSignature) bool {
+	return other.Type() == TypeNil
 }
 
-	return other.Type() == TypeAny || other.Type() == TypeNil
+func (s *NilSignature) Equal(other TypeSignature) bool {
+	return other.Type() == TypeNil
 }
 
 func (*NilSignature) String() string {
@@ -131,16 +149,16 @@ func (*StringSignature) Type() Type {
 	return TypeString
 }
 
-func (s *StringSignature) Matches(other TypeSignature) bool {
-	if other.Type() == TypeComposite {
-		return other.Matches(s)
+func (s *StringSignature) Contains(other TypeSignature) bool {
+	return other.Type() == TypeString
 }
 
-	return other.Type() == TypeAny || other.Type() == TypeString
+func (s *StringSignature) Equal(other TypeSignature) bool {
+	return other.Type() == TypeString
 }
 
 func (*StringSignature) String() string {
-	return "string"
+	return "str"
 }
 
 type FloatSignature struct{}
@@ -149,12 +167,12 @@ func (*FloatSignature) Type() Type {
 	return TypeFloat
 }
 
-func (s *FloatSignature) Matches(other TypeSignature) bool {
-	if other.Type() == TypeComposite {
-		return other.Matches(s)
+func (s *FloatSignature) Contains(other TypeSignature) bool {
+	return other.Type() == TypeFloat
 }
 
-	return other.Type() == TypeAny || other.Type() == TypeFloat
+func (s *FloatSignature) Equal(other TypeSignature) bool {
+	return other.Type() == TypeFloat
 }
 
 func (*FloatSignature) String() string {
@@ -167,12 +185,12 @@ func (*IntegerSignature) Type() Type {
 	return TypeInteger
 }
 
-func (s *IntegerSignature) Matches(other TypeSignature) bool {
-	if other.Type() == TypeComposite {
-		return other.Matches(s)
+func (s *IntegerSignature) Contains(other TypeSignature) bool {
+	return other.Type() == TypeInteger
 }
 
-	return other.Type() == TypeAny || other.Type() == TypeInteger
+func (s *IntegerSignature) Equal(other TypeSignature) bool {
+	return other.Type() == TypeInteger
 }
 
 func (*IntegerSignature) String() string {
@@ -185,12 +203,12 @@ func (*BooleanSignature) Type() Type {
 	return TypeBoolean
 }
 
-func (s *BooleanSignature) Matches(other TypeSignature) bool {
-	if other.Type() == TypeComposite {
-		return other.Matches(s)
+func (s *BooleanSignature) Contains(other TypeSignature) bool {
+	return other.Type() == TypeBoolean
 }
 
-	return other.Type() == TypeAny || other.Type() == TypeBoolean
+func (s *BooleanSignature) Equal(other TypeSignature) bool {
+	return other.Type() == TypeBoolean
 }
 
 func (*BooleanSignature) String() string {
@@ -205,16 +223,75 @@ func (*ListSignature) Type() Type {
 	return TypeList
 }
 
-func (s *ListSignature) Matches(other TypeSignature) bool {
-	if other.Type() == TypeComposite {
-		return other.Matches(s)
+func (s *ListSignature) Contains(other TypeSignature) bool {
+	return other.Type() == TypeList && other.(*ListSignature).Contents.Contains(s.Contents)
 }
 
-	return other.Type() == TypeAny || (other.Type() == TypeList && other.(*ListSignature).Contents.Matches(s.Contents))
+func (s *ListSignature) Equal(other TypeSignature) bool {
+	return other.Type() == TypeList && other.(*ListSignature).Contents.Equal(s.Contents)
 }
 
 func (s *ListSignature) String() string {
-	return fmt.Sprintf("list[%s]", s.Contents)
+	return fmt.Sprintf("[%s]", s.Contents)
+}
+
+type TupleSignature struct {
+	Contents []TypeSignature
+}
+
+func (*TupleSignature) Type() Type {
+	return TypeTuple
+}
+
+func (s *TupleSignature) Contains(other TypeSignature) bool {
+	if other.Type() != TypeTuple || len(other.(*TupleSignature).Contents) != len(s.Contents) {
+		return false
+	}
+
+	n := other.(*TupleSignature).Contents
+	for i, c := range s.Contents {
+		if !c.Contains(n[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (s *TupleSignature) Equal(other TypeSignature) bool {
+	if other.Type() != TypeTuple {
+		return false
+	}
+
+	n := other.(*TupleSignature).Contents
+	for i, c := range s.Contents {
+		if !c.Equal(n[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (s *TupleSignature) String() string {
+
+	sb := strings.Builder{}
+
+	sb.WriteString("(")
+	for i, t := range s.Contents {
+		if i > 0 {
+			sb.WriteString(",")
+			sb.WriteString(" ")
+		}
+		sb.WriteString(t.String())
+	}
+
+	if len(s.Contents) <= 1 {
+		sb.WriteString(",")
+	}
+	sb.WriteString(")")
+
+	return sb.String()
 }
 
 type ObjectSignature struct {
@@ -225,25 +302,13 @@ func (*ObjectSignature) Type() Type {
 	return TypeObject
 }
 
-func (s *ObjectSignature) Matches(other TypeSignature) bool {
-	if other.Type() == TypeComposite {
-		return other.Matches(s)
-	}
-
-	if other.Type() == TypeAny {
-		return true
-	}
-
+func (s *ObjectSignature) Contains(other TypeSignature) bool {
 	if other.Type() != TypeObject {
 		return false
 	}
 
 	o := other.(*ObjectSignature)
 
-	if len(o.Members) != len(s.Members) {
-		return false
-	}
-
 	for name, member := range s.Members {
 		v, ok := o.Members[name]
 
@@ -251,7 +316,29 @@ func (s *ObjectSignature) Matches(other TypeSignature) bool {
 			return false
 		}
 
-		if !v.Matches(member) {
+		if !v.Contains(member) {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (s *ObjectSignature) Equal(other TypeSignature) bool {
+	if other.Type() != TypeObject {
+		return false
+	}
+
+	if len(s.Members) != len(other.(*ObjectSignature).Members) {
+		return false
+	}
+
+	for name, member := range s.Members {
+		v, ok := other.(*ObjectSignature).Members[name]
+		if !ok {
+			return false
+		}
+		if !v.Equal(member) {
 			return false
 		}
 	}
@@ -272,22 +359,14 @@ func (*FunctionSignature) Type() Type {
 	return TypeFunction
 }
 
-func (s *FunctionSignature) Matches(other TypeSignature) bool {
-	if other.Type() == TypeComposite {
-		return other.Matches(s)
-	}
-
-	if other.Type() == TypeAny {
-		return true
-	}
-
+func (s *FunctionSignature) Contains(other TypeSignature) bool {
 	if other.Type() != TypeFunction {
 		return false
 	}
 
 	f := other.(*FunctionSignature)
 
-	if !s.Out.Matches(f.Out) {
+	if !s.Out.Contains(f.Out) {
 		return false
 	}
 
@@ -297,7 +376,7 @@ func (s *FunctionSignature) Matches(other TypeSignature) bool {
 
 	for i, p := range s.In {
 		v := f.In[i]
-		if !p.Matches(v) {
+		if !p.Contains(v) {
 			return false
 		}
 	}
@@ -305,10 +384,30 @@ func (s *FunctionSignature) Matches(other TypeSignature) bool {
 	return true
 }
 
+func (s *FunctionSignature) Equal(other TypeSignature) bool {
+	if other.Type() != TypeFunction {
+		return false
+	}
+
+	f := other.(*FunctionSignature)
+	if len(f.In) != len(s.In) {
+		return false
+	}
+
+	for i, p := range s.In {
+		v := f.In[i]
+		if !p.Equal(v) {
+			return false
+		}
+	}
+
+	return f.Out.Equal(s.Out)
+}
+
 func (s *FunctionSignature) String() string {
 	b := strings.Builder{}
 
-	b.WriteString("func(")
+	b.WriteString("fn(")
 
 	for i, t := range s.In {
 		if i > 0 {
@@ -319,7 +418,7 @@ func (s *FunctionSignature) String() string {
 
 	b.WriteString(")")
 	if s.Out.Type() != TypeNil {
-		b.WriteString(" ")
+		b.WriteString(" -> ")
 		b.WriteString(s.Out.String())
 	}
 
@@ -332,10 +431,14 @@ func (*AnySignature) Type() Type {
 	return TypeAny
 }
 
-func (*AnySignature) Matches(_ TypeSignature) bool {
+func (*AnySignature) Contains(_ TypeSignature) bool {
 	return true
 }
 
+func (s *AnySignature) Equal(t TypeSignature) bool {
+	return t.Type() == TypeAny
+}
+
 func (*AnySignature) String() string {
 	return "any"
 }
@@ -349,24 +452,72 @@ func (*CompositeSignature) Type() Type {
 	return TypeComposite
 }
 
-func (s *CompositeSignature) Matches(other TypeSignature) bool {
-	return s.A.Matches(other) || s.B.Matches(other)
+func (s *CompositeSignature) Contains(other TypeSignature) bool {
+	return s.A.Contains(other) || s.B.Contains(other)
+}
+
+func (s *CompositeSignature) Equal(t TypeSignature) bool {
+	return t.Type() == TypeComposite && s.A.Equal(t.(*CompositeSignature).A) && s.B.Equal(t.(*CompositeSignature).B)
 }
 
 func (s *CompositeSignature) String() string {
 	return fmt.Sprintf("%s|%s", s.A, s.B)
 }
 
+func quickComposite(a ...TypeSignature) TypeSignature {
+	switch len(a) {
+	case 0:
+		panic("quick composite: empty array")
+	case 1:
+		return a[0]
+	}
+
+	s := a[0]
+	for i := 1; i < len(a); i++ {
+		v := a[i]
+		s = &CompositeSignature{
+			A: s,
+			B: v,
+		}
+	}
+
+	return s
+}
+
 type InnerSignature struct{}
 
 func (*InnerSignature) Type() Type {
 	return TypeInner
 }
 
-func (*InnerSignature) Matches(_ TypeSignature) bool {
+func (*InnerSignature) Contains(_ TypeSignature) bool {
 	return false
 }
 
+func (s *InnerSignature) Equal(t TypeSignature) bool {
+	return t.Type() == TypeInner
+}
+
 func (*InnerSignature) String() string {
 	return "inner"
 }
+
+type NamedSignature struct {
+	Name string
+}
+
+func (*NamedSignature) Type() Type {
+	return TypeNamed
+}
+
+func (s *NamedSignature) Contains(t TypeSignature) bool {
+	return t.Type() == TypeNamed && s.Name == t.(*NamedSignature).Name
+}
+
+func (s *NamedSignature) Equal(t TypeSignature) bool {
+	return t.Type() == TypeNamed && s.Name == t.(*NamedSignature).Name
+}
+
+func (s *NamedSignature) String() string {
+	return s.Name
+}

core/values.go

@@ -6,6 +6,7 @@ import (
 	"math/big"
 	"reflect"
 	"strconv"
+	"strings"
 )
 
 type ValueType int
@@ -17,6 +18,7 @@ const (
 	IntegerValueType
 	StringValueType
 	ListValueType
+	TupleValueType
 	ObjectValueType
 	FunctionValueType
 	BuiltinFunctionValueType
@@ -39,6 +41,8 @@ func (v ValueType) String() string {
 		return "string"
 	case ListValueType:
 		return "list"
+	case TupleValueType:
+		return "tuple"
 	case FunctionValueType:
 		return "function"
 	case BuiltinFunctionValueType:
@@ -219,8 +223,8 @@ func (v *ObjectValue) Equals(other Value) bool {
 	return true
 }
 
-var ObjectPrototype = map[string]Value{
-	"set": &BuiltinFunctionValue{
+var ObjectPrototype = map[string]*BuiltinFunctionValue{
+	"set": {
 		"set",
 		&FunctionSignature{
 			[]TypeSignature{&StringSignature{}, &ListSignature{}},
@@ -278,7 +282,12 @@ func (v *FloatValue) Type() ValueType {
 }
 
 func (v *FloatValue) String() string {
-	return strconv.FormatFloat(v.Number, 'g', -1, FloatSize)
+	s := strconv.FormatFloat(v.Number, 'g', -1, FloatSize)
+	if strings.Index(s, ".") == -1 {
+		s += ".0"
+	}
+
+	return s
 }
 
 func (v *FloatValue) DebugString() string {
@@ -597,6 +606,88 @@ func (v *ListValue) Clone() Value {
 	}
 }
 
+type TupleValue struct {
+	Items []Value
+}
+
+func (v *TupleValue) Type() ValueType {
+	return TupleValueType
+}
+
+func (v *TupleValue) String() string {
+	out := "("
+	for i, item := range v.Items {
+		if i != 0 {
+			out += ", "
+		}
+		out += item.DebugString()
+	}
+
+	if len(v.Items) <= 1 {
+		out += ","
+	}
+	out += ")"
+
+	return out
+}
+
+func (v *TupleValue) DebugString() string {
+	return v.String()
+}
+
+func (v *TupleValue) Clone() Value {
+	n := make([]Value, len(v.Items))
+	for i, item := range v.Items {
+		n[i] = item.Clone()
+	}
+	return &TupleValue{
+		n,
+	}
+}
+
+func (v *TupleValue) Equals(other Value) bool {
+	if other.Type() != TupleValueType {
+		return false
+	}
+
+	t := other.(*TupleValue).Items
+	for i, item := range v.Items {
+		if !item.Equals(t[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
+var TuplePrototype = map[string]*BuiltinFunctionValue{
+	"at": &BuiltinFunctionValue{
+		"at",
+		&FunctionSignature{
+			[]TypeSignature{&IntegerSignature{}},
+			&InnerSignature{},
+		},
+		func(vm *VM, this Value, args []Value) (Value, error) {
+			i := args[0].(*IntegerValue).Number.Int64()
+
+			if i < 0 || i >= int64(len(this.(*TupleValue).Items)) {
+				return nil, errors.New(fmt.Sprintf("index %x out of range", i))
+			}
+
+			return this.(*TupleValue).Items[i], nil
+		},
+		nil,
+		true,
+	},
+}
+
+func (v *TupleValue) Get(key string) (Value, error) {
+	if prop, ok := TuplePrototype[key]; ok {
+		return prop, nil
+	}
+	return nil, errors.New(fmt.Sprintf("tuple has no property \"%s\"", key))
+}
+
 type FunctionValue struct {
 	Name   string
 	Params []FunctionParameter
@@ -651,7 +742,7 @@ func (v *BuiltinFunctionValue) Type() ValueType {
 }
 
 func (v *BuiltinFunctionValue) String() string {
-	return fmt.Sprintf("<function name=%s builtin>", v.Name)
+	return fmt.Sprintf("<function builtin name=%s>", v.Name)
 }
 
 func (v *BuiltinFunctionValue) DebugString() string {

core/values_test.go

@@ -66,7 +66,7 @@ func CompareValues(t *testing.T, got Value, want Value) {
 			t.Errorf("builtin function name mismatch: got %v, want %v", n.Name, m.Name)
 		}
 
-		if !n.Signature.Matches(m.Signature) {
+		if !n.Signature.Contains(m.Signature) {
 			t.Errorf("builtin function parameter count mismatch: got %v, want %v", n, m)
 		}
 
@@ -96,6 +96,19 @@ func CompareValues(t *testing.T, got Value, want Value) {
 			CompareValues(t, v, m.Members[k])
 		}
 
+	case TupleValueType:
+		n := got.(*TupleValue)
+		m := want.(*TupleValue)
+
+		if len(n.Items) != len(m.Items) {
+			t.Fatalf("tuple item count mismatch: got %d items, want %d items", len(n.Items), len(m.Items))
+		}
+
+		for i, v := range n.Items {
+			t.Logf("comparing tuple item #%d", i)
+			CompareValues(t, v, m.Items[i])
+		}
+
 	default:
 		panic("unimplemented comparison")
 	}

core/vm.go

@@ -41,6 +41,8 @@ const (
 	InstructionMulInt
 	// InstructionDivInt pop two ints and divide the second by the first
 	InstructionDivInt
+	// InstructionModInt pop two ints and compute the modulo of the first by the second
+	InstructionModInt
 	// InstructionNegateInt negate the int; if it was positive, make it negative, and vice versa.
 	InstructionNegateInt
 
@@ -99,8 +101,8 @@ const (
 
 	// InstructionStringConversion Take the top value on the stack and convert it to a string
 	InstructionStringConversion
-	// InstructionStringConcatenation Add two strings together, with the second value on the stack as left and the top as right
-	InstructionStringConcatenation
+	// InstructionConcatStrings Add two strings together, with the second value on the stack as left and the top as right
+	InstructionConcatStrings
 
 	// InstructionSwap swap the two top items on the stack (1, 2 -> 2, 1)
 	InstructionSwap
@@ -121,17 +123,33 @@ const (
 	// InstructionNil Push a nil literal to the stack
 	InstructionNil
 
-	// InstructionNewList Push a new (empty) list to the stack
-	InstructionNewList
 	// InstructionAppend Append to a list. stack: (... > list > item) => (... > list)
 	InstructionAppend
 	// InstructionFormList Form items on the stack into a list. The 2 bytes after the instructions are the amount of
-	// items to include minus one. (value of 0 => 1 item, value of 1 => 2 items, etc.) The order is reversed compared
-	// to on the stack; the top value on the stack is the last in the list.
+	// items to include) The order is reversed compared to on the stack; the top value on the stack is the last in the
+	// list.
 	InstructionFormList
 	// InstructionConcatLists concatenate lists, producing a new list with the values of both lists. Pops two lists.
 	InstructionConcatLists
 
+	// InstructionFormTuple pop n+1 (u16) items from the stack, and create a new tuple with the items. The top value
+	// on the stack is the last value in the tuple.
+	InstructionFormTuple
+	// InstructionDestructureTuple pop a tuple, and push all its items to the stack, with the top item on the stack
+	// being the last item in the tuple.
+	InstructionDestructureTuple
+
+	// InstructionIndexList index into a list. The lower item is the container, and the top item
+	// is the index. [..., container, index] -> [..., item]
+	InstructionIndexList
+	// InstructionIndexTuple index into a tuple. The lower item is the container, and the top item
+	// is the index. [..., container, index] -> [..., item]
+	InstructionIndexTuple
+	// InstructionIndexString index into a string. The lower item is the container, and the top item
+	// is the index. [..., container, index] -> [..., item]. Produces a new string with the character
+	// at the position
+	InstructionIndexString
+
 	// InstructionBreakpoint for debugging purposes
 	InstructionBreakpoint
 )
@@ -216,7 +234,7 @@ func (b Bytecode) String() string {
 		return "ASCEND"
 	case InstructionStringConversion:
 		return "STRING_CONVERSION"
-	case InstructionStringConcatenation:
+	case InstructionConcatStrings:
 		return "STRING_CONCATENATION"
 	case InstructionSwap:
 		return "SWAP"
@@ -228,8 +246,6 @@ func (b Bytecode) String() string {
 		return "FORM_LIST"
 	case InstructionBreakpoint:
 		return "BREAKPOINT"
-	case InstructionNewList:
-		return "NEW_LIST"
 	case InstructionAppend:
 		return "APPEND"
 	case InstructionAccessProperty:
@@ -238,6 +254,14 @@ func (b Bytecode) String() string {
 		return "CONCAT_LISTS"
 	case InstructionDuplicate:
 		return "DUPLICATE"
+	case InstructionFormTuple:
+		return "FORM_TUPLE"
+	case InstructionIndexList:
+		return "INDEX_LIST"
+	case InstructionIndexTuple:
+		return "INDEX_TUPLE"
+	case InstructionDestructureTuple:
+		return "DESTRUCTURE_TUPLE"
 	}
 	return "UNDEFINED"
 }
@@ -247,7 +271,7 @@ type Chunk struct {
 	Constants []Value
 }
 
-func (c Chunk) String() string {
+func (c *Chunk) String() string {
 	b := strings.Builder{}
 
 	b.WriteString("=v= chunk =v=\n")
@@ -320,7 +344,7 @@ func RegisterGOBTypes() {
 
 }
 
-func (c Chunk) Serialize() []byte {
+func (c *Chunk) Serialize() []byte {
 	b := bytes.Buffer{}
 
 	e := gob.NewEncoder(&b)
@@ -549,7 +573,13 @@ var DefaultGlobals = map[string]Value{
 	"int": &BuiltinFunctionValue{
 		"int",
 		&FunctionSignature{
-			[]TypeSignature{&AnySignature{}},
+			[]TypeSignature{
+				quickComposite(
+					&IntegerSignature{},
+					&FloatSignature{},
+					&StringSignature{},
+				),
+			},
 			&CompositeSignature{
 				&IntegerSignature{},
 				&NilSignature{},
@@ -570,7 +600,7 @@ var DefaultGlobals = map[string]Value{
 
 				return &IntegerValue{n}, nil
 			default:
-				return nil, errors.New(fmt.Sprintf("%s cannot become an integer", v))
+				return nil, errors.New(fmt.Sprintf("%s cannot become an integer (undefined)", v))
 			}
 		},
 		nil,
@@ -579,35 +609,38 @@ var DefaultGlobals = map[string]Value{
 	"float": &BuiltinFunctionValue{
 		"float",
 		&FunctionSignature{
-			[]TypeSignature{&AnySignature{}},
-			&CompositeSignature{
+			[]TypeSignature{
+				quickComposite(
 					&FloatSignature{},
-				&NilSignature{},
+					&IntegerSignature{},
+					&StringSignature{},
+				),
 			},
+			&FloatSignature{},
 		},
 		func(vm *VM, _ Value, args []Value) (Value, error) {
 			switch v := args[0].(type) {
 			case *IntegerValue:
 				n, _ := v.Number.Float64()
-				return &FloatValue{n}, nil // this might need to clone the value instead
+				return &FloatValue{n}, nil
 			case *FloatValue:
-				return &FloatValue{v.Number}, nil
+				return v.Clone(), nil
 			case *StringValue:
 				num, err := strconv.ParseFloat(v.Text, FloatSize)
 				if err != nil {
-					return &NilValue{}, nil
+					return &FloatValue{}, nil
 				}
 
 				return &FloatValue{num}, nil
 			default:
-				return nil, errors.New(fmt.Sprintf("%s cannot become an integer", v))
+				return nil, errors.New(fmt.Sprintf("%s cannot become an integer (undefined)", v))
 			}
 		},
 		nil,
 		true,
 	},
-	"type": &BuiltinFunctionValue{
-		Name: "type",
+	"typeof": &BuiltinFunctionValue{
+		Name: "typeof",
 		Signature: &FunctionSignature{
 			In:  []TypeSignature{&AnySignature{}},
 			Out: &StringSignature{},
@@ -660,12 +693,12 @@ var DefaultGlobals = map[string]Value{
 	"roundd": &BuiltinFunctionValue{
 		"roundd",
 		&FunctionSignature{
-			[]TypeSignature{&FloatSignature{}, &FloatSignature{}},
+			[]TypeSignature{&FloatSignature{}, &IntegerSignature{}},
 			&FloatSignature{},
 		},
 		func(vm *VM, this Value, args []Value) (Value, error) {
 			x := args[0].(*FloatValue).Number
-			decimals := args[1].(*FloatValue).Number
+			decimals, _ := args[1].(*IntegerValue).Number.Float64()
 			multiplier := math.Pow(10, decimals)
 			return &FloatValue{math.Round(x*multiplier) / multiplier}, nil
 		},
@@ -779,6 +812,12 @@ func (vm *VM) Next() bool {
 
 		vm.Stack.Push(&IntegerValue{new(big.Int).Div(l, r)})
 
+	case InstructionModInt:
+		r := vm.Stack.Pop().(*IntegerValue).Number
+		l := vm.Stack.Pop().(*IntegerValue).Number
+
+		vm.Stack.Push(&IntegerValue{new(big.Int).Mod(l, r)})
+
 	case InstructionNegateInt:
 		v := vm.Stack.Pop().(*IntegerValue).Number
 
@@ -963,9 +1002,6 @@ func (vm *VM) Next() bool {
 			items,
 		})
 
-	case InstructionNewList:
-		vm.Stack.Push(&ListValue{[]Value{}})
-
 	case InstructionAppend:
 		value := vm.Stack.Pop()
 		list := vm.Stack.Pop().(*ListValue)
@@ -980,6 +1016,23 @@ func (vm *VM) Next() bool {
 			append(l.Items, r.Items...),
 		})
 
+	case InstructionFormTuple:
+		n := int(vm.NextU16())
+
+		items := make([]Value, n)
+		for i := n - 1; i >= 0; i-- {
+			items[i] = vm.Stack.Pop()
+		}
+
+		vm.Stack.Push(&TupleValue{
+			items,
+		})
+
+	case InstructionDestructureTuple:
+		t := vm.Stack.Pop().(*TupleValue)
+
+		vm.Stack.Push(t.Items...)
+
 	case InstructionDescend:
 		vm.descend()
 
@@ -990,7 +1043,7 @@ func (vm *VM) Next() bool {
 		v := vm.Stack.Pop()
 		vm.Stack.Push(&StringValue{v.String()})
 
-	case InstructionStringConcatenation:
+	case InstructionConcatStrings:
 		r := vm.Stack.Pop().(*StringValue).Text
 		l := vm.Stack.Pop().(*StringValue).Text
 
@@ -1023,6 +1076,42 @@ func (vm *VM) Next() bool {
 
 		vm.Stack.Push(member)
 
+	case InstructionIndexList:
+		i := vm.Stack.Pop().(*IntegerValue)
+		l := vm.Stack.Pop().(*ListValue)
+
+		n := int(i.Number.Int64())
+
+		if n < 0 || len(l.Items) <= n {
+			vm.error(fmt.Sprintf("index %d out of bounds", n))
+		}
+
+		vm.Stack.Push(l.Items[n].Clone())
+
+	case InstructionIndexTuple:
+		i := vm.Stack.Pop().(*IntegerValue)
+		t := vm.Stack.Pop().(*TupleValue)
+
+		n := int(i.Number.Int64())
+
+		if n < 0 || len(t.Items) <= n {
+			vm.error(fmt.Sprintf("index %d out of bounds", n))
+		}
+
+		vm.Stack.Push(t.Items[n].Clone())
+
+	case InstructionIndexString:
+		i := vm.Stack.Pop().(*IntegerValue)
+		s := vm.Stack.Pop().(*StringValue)
+
+		n := int(i.Number.Int64())
+
+		if n < 0 || len(s.Text) <= n {
+			vm.error(fmt.Sprintf("index %d out of bounds", n))
+		}
+
+		vm.Stack.Push(&StringValue{string(s.Text[n])})
+
 	case InstructionBreakpoint:
 		/*
 			// I'm keeping this

core/vm_test.go

@@ -2,6 +2,7 @@ package core
 
 import (
 	"fmt"
+	"math/big"
 	"testing"
 )
 
@@ -615,6 +616,28 @@ func GetExecutionTestData() map[string]struct {
 			},
 			[]map[string]Value{},
 		},
+		"form_tuple": {
+			&Chunk{
+				Bytecode: []Bytecode{
+					InstructionConstant, 0,
+					InstructionConstant, 1,
+					InstructionFormTuple, 0, 2,
+				},
+				Constants: []Value{
+					&IntegerValue{big.NewInt(1)},
+					&IntegerValue{big.NewInt(2)},
+				},
+			},
+			[]Value{
+				&TupleValue{
+					Items: []Value{
+						&IntegerValue{big.NewInt(1)},
+						&IntegerValue{big.NewInt(2)},
+					},
+				},
+			},
+			[]map[string]Value{},
+		},
 	}
 }
 

emoji.ang

@@ -1,2 +0,0 @@
-
-write(char(0x12) + char(0x85) + char(0x07))

era3.ang

@@ -1,11 +0,0 @@
-fn counter() -> (fn() -> int) {
-    i := 0
-
-    fn() -> int { i = i + 1 }
-}
-
-next := counter()
-
-println(next())
-println(next())
-println(next())

examples/arithmetics.ang

@@ -1,19 +1,20 @@
 
-write("Bonjour à tout!");
+println("Bonjour à tout!")
 
 if 1 == 2 {
     # unreachable
+    println("Wooot?? One does equal 2????")
 } else {
-    write("Hooray! One does not equal 2!");
+    println("Hooray! One does not equal 2!")
 }
 
-for (var n = 1; n < 10; n = n + 1) {
-    write("Run number " + str(n));
+for n in 0..10 {
+    println("Run number " + str(n))
 }
 
-var a = 2;
+a := 2
 
-write(3 * a*a + 10 / 3);
+println(3 * a*a + 10 / 3)
 
 
 

examples/fib.ang

@@ -1,17 +1,21 @@
 
 # calculate fibonacci numbers with a loop
 
-x := 0
+fn range(from: int, to: int) -> (fn() -> (int, bool)) {
+    i := from - 1
+    end := to - 1
 
-n := 1
-p := 1
-
-while x < 100 {
-    f := n + p
-
-    p = n
-    n = f
-
-    write(f)
-    x = x + 1
+    fn() -> (int, bool) {
+        if i < end {
+            (i = i+1, true)
+        } else {
+            (-1, false)
+        }
+    }
+}
+
+(a, b) := (0, 1)
+for _ in range(0, 100) {
+    (a, b) = (a + b, a)
+    println(a)
 }

examples/func.ang

@@ -1,6 +1,6 @@
 
-func sum(a, b) {
-    return a + b
+fn sum(a: int, b: int) -> int {
+    a + b
 }
 
-write(sum(1, 2))
+println(sum(1, 2))

examples/grapher.ang

@@ -1,4 +1,4 @@
-func f(x) {
+fn f(x) {
     return x*x - 4
 }
 

examples/hello.ang

@@ -1,13 +1,11 @@
 
-write("Hello world!")
+println("Hello world!")
 
 a := 1 + 2
-
-write(a)
-
+println(a)
 
 if a > 2 {
-    write("Hooray!! a is greater than 2!!!!")
+    println("Hooray!! a is greater than 2!!!!")
 } else {
-    write("oh nooo!!! a is less than or equal to 2!!!!!!!!!!")
+    println("oh nooo!!! a is less than or equal to 2!!!!!!!!!!")
 }

examples/importing.ang

@@ -1,3 +1,3 @@
 import "math.ang"
 
-write(sqrt(2))
+println(sqrt(2.0))

examples/list.ang

@@ -1,51 +1,47 @@
 
 # Empty list
-write([])
+println([])
 
 # List with items
-write([3, 1, 4, 1, 5, 9, 2, 6, 5])
+println([3, 1, 4, 1, 5, 9, 2, 6, 5])
 
 # List with items of different types
-write(["", "私はかっこいいです。", true, nil, nil, 1, 2])
+println(["", "私はかっこいいです。", true, nil, nil, 1, 2])
 
 a := []
 
-a = a.append(1)
-a = a.append(2)
+a = a + [1]
+a = a + [2]
 
-write(a)
+println(a)
 
 
 list := []
 
-n := 0
 x := 0
-while n < 100 {
+for n in 0..100 {
     x = x + 2*n + 1
 
-    list = list.append(x)
-    n = n + 1
+    list = list + [x]
 }
 
-write(list)
-write(list.map(func(a) {
+println(list)
+println(list.map(func(a) {
     return a - 1
 }))
-write(list.length())
-write(list.at(69))
+println(list.length())
+println(list.at(69))
 
 other := []
 
-a := 1
-while a <= 10 {
+for a in 0..=10 {
     other = other.append(a)
-    a = a + 1
 }
 
 sum := other.reduce(func(tot, x) {
     return tot + x
 }, 0)
 
-write(sum)
+println(sum)
 
 assert(sum == a*(a-1)/2)

examples/pi-approx.ang

@@ -20,9 +20,10 @@ tot = tot * 6.0
 # get the absolute value of a number
 fn abs(x: float) -> float {
 	if x < 0.0 {
-		return -x
+		-x
+	} else {
+	    x
 	}
-	return x
 }
 
 # calculate an approximation of the square root of tot using

examples/pøck.ang

@@ -1,16 +1,15 @@
 import "math.ang"
 
-func r_x(t) {
-    return 8*(exp(-t) - t)
+fn r_x(t: float) -> float {
+    return 8.0*(exp(-t) - t)
 }
 
-func r_y(t) {
-    return 5*(exp(-t) - t)
+fn r_y(t: float) -> float {
+    return 5.0*(exp(-t) - t)
 }
 
-func r(t) {
-    return format("(%s, %s)", [r_x(t), r_y(t)])
+fn r(t: float) -> (float, float) {
+    return (r_x(t), r_y(t))
 }
 
-write(r(1))
-write()
+println(r(1.0))

fails.ang

@@ -1,4 +0,0 @@
-import "lib/honning.ang"
-
-write(_bell+_italic+"Hello "+_underline+"world "+_strike+"micheal"+_reset)
-

imp.ang

@@ -1,15 +0,0 @@
-
-func is_cool(x: number|string) boolean {
-    if x == "cool" {
-        return true
-    } else if x == 69 {
-        return true
-    }
-
-    return nil
-}
-
-write(str(is_cool("not cool")))
-write(str(is_cool("cool")))
-write(str(is_cool(0)))
-write(str(is_cool(69)))

lib/list.ang

@@ -1,5 +1,5 @@
 
-fn map(list: [any], f: fn(any) -> any) -> [any] {
+fn (l: list) map(list: [any], f: fn(any) -> any) -> [any] {
     out := []
 
     i := 0

lib/math.ang

@@ -9,7 +9,7 @@ E := 2.718281828459045235360287471352
 #   returned value is x.
 fn absf(x: float) -> float {
     # if the number is negative
-    if x < 0 {
+    if x < 0.0 {
         # negate it so it's positive
         return -x
     }
@@ -26,7 +26,7 @@ fn absi(n: int) -> int {
 }
 
 DERIVE_DX := 0.00000001
-fn derive(f: fn(float) -> float, x: float) float {
+fn derive(f: fn(float) -> float, x: float) -> float {
     return (f(x + DERIVE_DX) - f(x))/DERIVE_DX
 }
 
@@ -35,7 +35,7 @@ fn newtons(f: fn(float) -> float) -> float {
     pg := 0.0
     g := 1.0
 
-    while abs(g - pg) > NEWTONS_ACC {
+    while absf(g - pg) > NEWTONS_ACC {
         pg = g
         g = pg - f(pg) / derive(f, pg)
     }
@@ -53,12 +53,14 @@ fn sqrt(x: float) -> float {
     ng := x
     g := 1.0
 
-    while abs(g - ng) > MAX_SQRT_DX {
+    while absf(g - ng) > MAX_SQRT_DX {
         g = ng
 
         # create new guess
-        ng = (g + x / g) / 2
+        ng = (g + x / g) / 2.0
     }
+
+    g
 }
 
 # floor(x)
@@ -82,7 +84,7 @@ fn round(x: float) -> float {
     f := floor(x)
 
     if x - f > 0.5 {
-        return f + 1
+        return f + 1.0
     }
 
     return f
@@ -93,16 +95,16 @@ fn round(x: float) -> float {
 # n: number; the number to divide by
 #   Return the rest from a division of x by n.
 fn mod(x: float, n: float) -> float {
-    if x == 0 {
-        return 0
+    if x == 0.0 {
+        return 0.0
     }
 
-    if x < 0 {
-        while x + n <= 0 {
+    if x < 0.0 {
+        while x + n <= 0.0 {
             x = x + n
         }
     } else {
-        while x - n >= 0 {
+        while x - n >= 0.0 {
             x = x - n
         }
     }
@@ -123,7 +125,7 @@ fn sm_exp(x: float) -> float {
     x_pow := x
     f := 1.0
 
-    while abs(tot - p_tot) > SM_EXP_ACC {
+    while absf(tot - p_tot) > SM_EXP_ACC {
         p_tot = tot
         t := x_pow / f
         tot = tot + t
@@ -139,18 +141,18 @@ fn sm_exp(x: float) -> float {
 # x: number; any number
 #   Get an approximate value of e raised to the power of x.
 fn exp(x: float) -> float {
-    n := abs(x)
+    n := absf(x)
     tot := 1.0
-    while n >= 1 {
+    while n >= 1.0 {
         tot = tot * E
-        n = n - 1
+        n = n - 1.0
     }
 
     if n > 0.0 {
         tot = tot * sm_exp(n)
     }
 
-    if x < 0 {
+    if x < 0.0 {
         1.0/tot
     } else {
         tot
@@ -166,9 +168,9 @@ fn ln(x: float) -> float {
     pg := 0.0
     g := 1.0
 
-    while abs(pg - g) > LN_ACC {
+    while absf(pg - g) > LN_ACC {
         pg = g
-        g = pg + x / exp(pg) - 1
+        g = pg + x / exp(pg) - 1.0
     }
 
     return g
@@ -194,7 +196,7 @@ fn log(a: float, b: float) -> float {
     pg := 0.0
     g := 1.0
 
-    while abs(g - pg) > LOG_ACC {
+    while absf(g - pg) > LOG_ACC {
         pg = g
         g = pg - 1.0/ln_b - a/(ln_b*pow(b, pg))
     }
@@ -211,7 +213,7 @@ fn sin(x: float) -> float {
     x = mod(x, 2.0*PI)
     if x > PI {
         x = PI - x
-        f = -1
+        f = -1.0
     }
 
     # compute sine with a taylor series mock function of sine (valid between -pi and +pi)
@@ -220,7 +222,7 @@ fn sin(x: float) -> float {
     i := 1.0
     s := -1.0
 
-    while i <= 19 {
+    while i <= 19.0 {
         i = i + 2.0
         l = s * l * x / i / (i-1.0)
 
@@ -235,13 +237,15 @@ fn sin(x: float) -> float {
 # cos(x)
 # x: number; an angle in radians
 #   Get the cosine of an angle (in radians). https://en.wikipedia.org/wiki/Sine_and_cosine
-func cos(x: number) number {
+fn cos(x: float) -> float {
     # todo
+    0.0
 }
 
 # tan(x)
 # x: number; an angle in radians
 #   Get the tangent of an angle. https://en.wikipedia.org/wiki/Tangent
-func tan(x: number) number {
+fn tan(x: float) -> float {
     # todo
+    0.0
 }

tests/tuple.ang

@@ -0,0 +1,11 @@
+
+assertEq((1, 2), (1, 2))
+
+assertEq(typeof((1,)), typeof((1,)))
+assertEq((1,), (1,))
+
+fn neighbours(n: int) -> (int, int) {
+    (n-1, n+1)
+}
+
+assertEq(neighbours(2), (1, 3))

tests/types.ang

@@ -1,8 +1,15 @@
 
-assertEq(type(1), "int")
-assertEq(type("Hello"), "string")
-assertEq(type(true), "boolean")
+assertEq(typeof(1), "int")
+assertEq(typeof("Hello"), "string")
+assertEq(typeof(true), "boolean")
 
 # lists
-assertEq(type(["Hello", "world"]), "list[string]")
-assertEq(type([0, 1]), "list[int]")
+assertEq(typeof(["Hello", "world"]), "[string]")
+assertEq(typeof([0, 1]), "[int]")
+assertEq(typeof((0, 1)), "(int, int)")
+
+type Vec2 = (int, int)
+
+fn add(a: Vec2, b: Vec2) -> Vec2 {
+    (a[0] + b[0], a[1] + b[1])
+}

wasm/Makefile

@@ -0,0 +1,3 @@
+
+build:
+	GOOS=js GOARCH=wasm go build .