Switch to using func instead of fn

Author: ldemailly

README.md

@@ -8,7 +8,7 @@ CGO_ENABLED=0 go install -trimpath -ldflags="-w -s" -tags no_net,no_json github.
 Sample:
 ```shell
 gorepl -parse
-$ fact = fn(n) {if (n<1) {return 1} n*fact(n-1)}
+$ fact = func(n) {if (n<=1) {return 1} n*fact(n-1)}
 $ n=fact(6)
 == Parse ==> (n = fact(6))
 == Eval  ==> 720

apply.gr

@@ -2,13 +2,13 @@
 
 a = [ 1, 3, 5, 7]
 
-apply = fn(f, a) {
+apply = func(f, a) {
     if (len(a)==0) {
         return []
     }
     return [f(first(a))]+apply(f,rest(a))
 }
 
-apply(fn(x) {2*x}, a)
+apply(func(x) {2*x}, a)
 
 // ^^^ [2, 6, 10, 14]

ast/ast.go

@@ -283,7 +283,7 @@ func (b *Builtin) String() string {
 }
 
 type FunctionLiteral struct {
-	Base       // The 'fn' token
+	Base       // The 'func' token
 	Parameters []*Identifier
 	Body       *BlockStatement
 }

eval/eval_test.go

@@ -36,7 +36,7 @@ func TestEvalIntegerExpression(t *testing.T) {
 		{"19 % 5", 4},
 		{"20 % -5", 0},
 		{"-21 % 5", -1},
-		{`fact = fn(n) {if (n<2) {return 1} n*fact(n-1)}; fact(5)`, 120},
+		{`fact = func(n) {if (n<2) {return 1} n*fact(n-1)}; fact(5)`, 120},
 	}
 
 	for i, tt := range tests {
@@ -208,7 +208,7 @@ func TestErrorHandling(t *testing.T) {
 		expectedMessage string
 	}{
 		{
-			"let f=fn(x,y) {x+y}; f(1)",
+			"let f=func(x,y) {x+y}; f(1)",
 			"<wrong number of arguments. got=1, want=2>",
 		},
 		{
@@ -256,7 +256,7 @@ if (10 > 1) {
 			"<unknown operator: STRING - STRING>",
 		},
 		{
-			`{"name": "Monkey"}[fn(x) { x }];`,
+			`{"name": "Monkey"}[func(x) { x }];`,
 			"FUNCTION not usable as map key",
 		},
 	}
@@ -298,7 +298,7 @@ func TestLetStatements(t *testing.T) {
 }
 
 func TestFunctionObject(t *testing.T) {
-	input := "fn(x) { x + 2; };"
+	input := "func(x) { x + 2; };"
 
 	evaluated := testEval(t, input)
 	fn, ok := evaluated.(object.Function)
@@ -327,12 +327,12 @@ func TestFunctionApplication(t *testing.T) {
 		input    string
 		expected int64
 	}{
-		{"let identity = fn(x) { x; }; identity(5);", 5},
-		{"let identity = fn(x) { return x; }; identity(5);", 5},
-		{"let double = fn(x) { x * 2; }; double(5);", 10},
-		{"let add = fn(x, y) { x + y; }; add(5, 5);", 10},
-		{"let add = fn(x, y) { x + y; }; add(5 + 5, add(5, 5));", 20},
-		{"fn(x) { x; }(5)", 5},
+		{"let identity = func(x) { x; }; identity(5);", 5},
+		{"let identity = func(x) { return x; }; identity(5);", 5},
+		{"let double = func(x) { x * 2; }; double(5);", 10},
+		{"let add = func(x, y) { x + y; }; add(5, 5);", 10},
+		{"let add = func(x, y) { x + y; }; add(5 + 5, add(5, 5));", 20},
+		{"func(x) { x; }(5)", 5},
 	}
 	for _, tt := range tests {
 		testIntegerObject(t, testEval(t, tt.input), tt.expected)
@@ -341,8 +341,8 @@ func TestFunctionApplication(t *testing.T) {
 
 func TestClosures(t *testing.T) {
 	input := `
-let newAdder = fn(x) {
-  fn(y) { x + y };
+let newAdder = func(x) {
+  func(y) { x + y };
 };
 
 let addTwo = newAdder(2);

lexer/lexer_test.go

@@ -10,7 +10,7 @@ func TestNextToken(t *testing.T) { //nolint:funlen // this is a test function wi
 	input := `let five = 5;
 let ten = 10;
 
-let add = fn(x, y) {
+let add = func(x, y) {
 x + y;
 };
 
@@ -53,7 +53,7 @@ return // nil return
 		{token.LET, "let"},
 		{token.IDENT, "add"},
 		{token.ASSIGN, "="},
-		{token.FUNCTION, "fn"},
+		{token.FUNCTION, "func"},
 		{token.LPAREN, "("},
 		{token.IDENT, "x"},
 		{token.COMMA, ","},

object/object.go

@@ -152,7 +152,7 @@ func (f Function) Type() Type { return FUNCTION }
 func (f Function) Inspect() string {
 	out := strings.Builder{}
 
-	out.WriteString("fn")
+	out.WriteString("func")
 	out.WriteString("(")
 	ast.WriteStrings(&out, f.Parameters, ", ")
 	out.WriteString(") ")

parser/parser_book_test.go

@@ -521,7 +521,7 @@ func TestIfElseExpression(t *testing.T) {
 }
 
 func TestFunctionLiteralParsing(t *testing.T) {
-	input := `fn(x, y) { x + y; }`
+	input := `func(x, y) { x + y; }`
 
 	l := lexer.New(input)
 	p := New(l)
@@ -573,9 +573,9 @@ func TestFunctionParameterParsing(t *testing.T) {
 		input          string
 		expectedParams []string
 	}{
-		{input: "fn() {};", expectedParams: []string{}},
-		{input: "fn(x) {};", expectedParams: []string{"x"}},
-		{input: "fn(x, y, z) {};", expectedParams: []string{"x", "y", "z"}},
+		{input: "func() {};", expectedParams: []string{}},
+		{input: "func(x) {};", expectedParams: []string{"x"}},
+		{input: "func(x, y, z) {};", expectedParams: []string{"x", "y", "z"}},
 	}
 
 	for _, tt := range tests {

parser/parser_test.go

@@ -358,8 +358,8 @@ func Test_OperatorPrecedenceParsing(t *testing.T) {
 			"let x = (41 * 6)",
 		},
 		{
-			"let foo = fn(a,b) {return a+b}",
-			"let foo = fn(a, b) {\nreturn (a + b)\n}",
+			"let foo = func(a,b) {return a+b}",
+			"let foo = func(a, b) {\nreturn (a + b)\n}",
 		},
 	}
 

sample.gr

@@ -2,7 +2,7 @@
 // <--- comments
 // See also the other *.gr files
 
-fact=fn(n) { // function
+fact=func(n) { // function
     if (n<=1) {
         return 1
     }

token/token.go

@@ -70,7 +70,7 @@ const (
 var _ = EOF.String() // force compile error if go generate is missing.
 
 var keywords = map[string]Type{
-	"fn":     FUNCTION,
+	"func":   FUNCTION,
 	"let":    LET,
 	"true":   TRUE,
 	"false":  FALSE,