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-rw-r--r--parser/parser_test.go820
1 files changed, 820 insertions, 0 deletions
diff --git a/parser/parser_test.go b/parser/parser_test.go
new file mode 100644
index 0000000..fa080aa
--- /dev/null
+++ b/parser/parser_test.go
@@ -0,0 +1,820 @@
+package parser
+
+import (
+ "fmt"
+ "monkey/ast"
+ "monkey/lexer"
+ "testing"
+)
+
+func TestLetStatements(t *testing.T) {
+ tests := []struct {
+ input string
+ expectedIdentifier string
+ expectedValue interface{}
+ }{
+ {"let x = 5;", "x", 5},
+ {"let y = true;", "y", true},
+ {"let foobar = y", "foobar", "y"},
+ }
+
+ for _, tt := range tests {
+ l := lexer.New(tt.input)
+ p := New(l)
+ program := p.ParseProgram()
+ checkParserErrors(t, p)
+
+ if len(program.Statements) != 1 {
+ t.Fatalf("program.Statements does not contain 1 statements. got=%d",
+ len(program.Statements))
+ }
+
+ stmt := program.Statements[0]
+ if !testLetStatement(t, stmt, tt.expectedIdentifier) {
+ return
+ }
+
+ val := stmt.(*ast.LetStatement).Value
+ if !testLiteralExpression(t, val, tt.expectedValue) {
+ return
+ }
+ }
+}
+
+func TestReturnStatements(t *testing.T) {
+ tests := []struct {
+ input string
+ expectedValue interface{}
+ }{
+ {"return 5;", 5},
+ {"return true;", true},
+ {"return foobar;", "foobar"},
+ }
+
+ for _, tt := range tests {
+ l := lexer.New(tt.input)
+ p := New(l)
+ program := p.ParseProgram()
+ checkParserErrors(t, p)
+
+ if len(program.Statements) != 1 {
+ t.Fatalf("program.Statements does not contain 1 statements. got=%d",
+ len(program.Statements))
+ }
+
+ stmt := program.Statements[0]
+ returnStmt, ok := stmt.(*ast.ReturnStatement)
+ if !ok {
+ t.Fatalf("stmt not *ast.returnStatement. got=%T", stmt)
+ }
+ if returnStmt.TokenLiteral() != "return" {
+ t.Fatalf("returnStmt.TokenLiteral not 'return', got %q",
+ returnStmt.TokenLiteral())
+ }
+ if testLiteralExpression(t, returnStmt.ReturnValue, tt.expectedValue) {
+ return
+ }
+ }
+}
+
+func TestIdentifierExpression(t *testing.T) {
+ input := "foobar;"
+
+ l := lexer.New(input)
+ p := New(l)
+ program := p.ParseProgram()
+ checkParserErrors(t, p)
+
+ if len(program.Statements) != 1 {
+ t.Fatalf("program has not enough statements. got=%d",
+ len(program.Statements))
+ }
+ stmt, ok := program.Statements[0].(*ast.ExpressionStatement)
+ if !ok {
+ t.Fatalf("program.Statements[0] is not ast.ExpressionStatement. got=%T",
+ program.Statements[0])
+ }
+
+ ident, ok := stmt.Expression.(*ast.Identifier)
+ if !ok {
+ t.Fatalf("exp not *ast.Identifier. got=%T", stmt.Expression)
+ }
+ if ident.Value != "foobar" {
+ t.Errorf("ident.Value not %s. got=%s", "foobar", ident.Value)
+ }
+ if ident.TokenLiteral() != "foobar" {
+ t.Errorf("ident.TokenLiteral not %s. got=%s", "foobar",
+ ident.TokenLiteral())
+ }
+}
+
+func TestIntegerLiteralExpression(t *testing.T) {
+ input := "5;"
+
+ l := lexer.New(input)
+ p := New(l)
+ program := p.ParseProgram()
+ checkParserErrors(t, p)
+
+ if len(program.Statements) != 1 {
+ t.Fatalf("program has not enough statements. got=%d",
+ len(program.Statements))
+ }
+ stmt, ok := program.Statements[0].(*ast.ExpressionStatement)
+ if !ok {
+ t.Fatalf("program.Statements[0] is not ast.ExpressionStatement. got=%T",
+ program.Statements[0])
+ }
+
+ literal, ok := stmt.Expression.(*ast.IntegerLiteral)
+ if !ok {
+ t.Fatalf("exp not *ast.IntegerLiteral. got=%T", stmt.Expression)
+ }
+ if literal.Value != 5 {
+ t.Errorf("literal.Value not %d. got=%d", 5, literal.Value)
+ }
+ if literal.TokenLiteral() != "5" {
+ t.Errorf("literal.TokenLiteral not %s. got=%s", "5",
+ literal.TokenLiteral())
+ }
+}
+
+func TestParsingPrefixExpressions(t *testing.T) {
+ prefixTests := []struct {
+ input string
+ operator string
+ value interface{}
+ }{
+ {"!5;", "!", 5},
+ {"-15;", "-", 15},
+ {"!foobar;", "!", "foobar"},
+ {"-foobar;", "-", "foobar"},
+ {"!true;", "!", true},
+ {"!false;", "!", false},
+ }
+
+ for _, tt := range prefixTests {
+ l := lexer.New(tt.input)
+ p := New(l)
+ program := p.ParseProgram()
+ checkParserErrors(t, p)
+
+ if len(program.Statements) != 1 {
+ t.Fatalf("program.Statements does not contain %d statements. got=%d\n",
+ 1, len(program.Statements))
+ }
+
+ stmt, ok := program.Statements[0].(*ast.ExpressionStatement)
+ if !ok {
+ t.Fatalf("program.Statements[0] is not ast.ExpressionStatement. got=%T",
+ program.Statements[0])
+ }
+
+ exp, ok := stmt.Expression.(*ast.PrefixExpression)
+ if !ok {
+ t.Fatalf("stmt is not ast.PrefixExpression. got=%T", stmt.Expression)
+ }
+ if exp.Operator != tt.operator {
+ t.Fatalf("exp.Operator is not '%s'. got=%s",
+ tt.operator, exp.Operator)
+ }
+ if !testLiteralExpression(t, exp.Right, tt.value) {
+ return
+ }
+ }
+}
+
+func TestParsingInfixExpressions(t *testing.T) {
+ infixTests := []struct {
+ input string
+ leftValue interface{}
+ operator string
+ rightValue interface{}
+ }{
+ {"5 + 5;", 5, "+", 5},
+ {"5 - 5;", 5, "-", 5},
+ {"5 * 5;", 5, "*", 5},
+ {"5 / 5;", 5, "/", 5},
+ {"5 > 5;", 5, ">", 5},
+ {"5 < 5;", 5, "<", 5},
+ {"5 == 5;", 5, "==", 5},
+ {"5 != 5;", 5, "!=", 5},
+ {"foobar + barfoo;", "foobar", "+", "barfoo"},
+ {"foobar - barfoo;", "foobar", "-", "barfoo"},
+ {"foobar * barfoo;", "foobar", "*", "barfoo"},
+ {"foobar / barfoo;", "foobar", "/", "barfoo"},
+ {"foobar > barfoo;", "foobar", ">", "barfoo"},
+ {"foobar < barfoo;", "foobar", "<", "barfoo"},
+ {"foobar == barfoo;", "foobar", "==", "barfoo"},
+ {"foobar != barfoo;", "foobar", "!=", "barfoo"},
+ {"true == true", true, "==", true},
+ {"true != false", true, "!=", false},
+ {"false == false", false, "==", false},
+ }
+
+ for _, tt := range infixTests {
+ l := lexer.New(tt.input)
+ p := New(l)
+ program := p.ParseProgram()
+ checkParserErrors(t, p)
+
+ if len(program.Statements) != 1 {
+ t.Fatalf("program.Statements does not contain %d statements. got=%d\n",
+ 1, len(program.Statements))
+ }
+
+ stmt, ok := program.Statements[0].(*ast.ExpressionStatement)
+ if !ok {
+ t.Fatalf("program.Statements[0] is not ast.ExpressionStatement. got=%T",
+ program.Statements[0])
+ }
+
+ if !testInfixExpression(t, stmt.Expression, tt.leftValue,
+ tt.operator, tt.rightValue) {
+ return
+ }
+ }
+}
+
+func TestOperatorPrecedenceParsing(t *testing.T) {
+ tests := []struct {
+ input string
+ expected string
+ }{
+ {
+ "-a * b",
+ "((-a) * b)",
+ },
+ {
+ "!-a",
+ "(!(-a))",
+ },
+ {
+ "a + b + c",
+ "((a + b) + c)",
+ },
+ {
+ "a + b - c",
+ "((a + b) - c)",
+ },
+ {
+ "a * b * c",
+ "((a * b) * c)",
+ },
+ {
+ "a * b / c",
+ "((a * b) / c)",
+ },
+ {
+ "a + b / c",
+ "(a + (b / c))",
+ },
+ {
+ "a + b * c + d / e - f",
+ "(((a + (b * c)) + (d / e)) - f)",
+ },
+ {
+ "3 + 4; -5 * 5",
+ "(3 + 4)((-5) * 5)",
+ },
+ {
+ "5 > 4 == 3 < 4",
+ "((5 > 4) == (3 < 4))",
+ },
+ {
+ "5 < 4 != 3 > 4",
+ "((5 < 4) != (3 > 4))",
+ },
+ {
+ "3 + 4 * 5 == 3 * 1 + 4 * 5",
+ "((3 + (4 * 5)) == ((3 * 1) + (4 * 5)))",
+ },
+ {
+ "3 + 4 * 5 == 3 * 1 + 4 * 5",
+ "((3 + (4 * 5)) == ((3 * 1) + (4 * 5)))",
+ },
+ {
+ "true",
+ "true",
+ },
+ {
+ "false",
+ "false",
+ },
+ {
+ "3 > 5 == false",
+ "((3 > 5) == false)",
+ },
+ {
+ "3 < 5 == true",
+ "((3 < 5) == true)",
+ },
+ {
+ "1 + (2 + 3) + 4",
+ "((1 + (2 + 3)) + 4)",
+ },
+ {
+ "(5 + 5) * 2",
+ "((5 + 5) * 2)",
+ },
+ {
+ "2 / (5 + 5)",
+ "(2 / (5 + 5))",
+ },
+ {
+ "(5 + 5) * 2 * (5 + 5)",
+ "(((5 + 5) * 2) * (5 + 5))",
+ },
+ {
+ "-(5 + 5)",
+ "(-(5 + 5))",
+ },
+ {
+ "!(true == true)",
+ "(!(true == true))",
+ },
+ {
+ "a + add(b * c) + d",
+ "((a + add((b * c))) + d)",
+ },
+ {
+ "add(a, b, 1, 2 * 3, 4 + 5, add(6, 7 * 8))",
+ "add(a, b, 1, (2 * 3), (4 + 5), add(6, (7 * 8)))",
+ },
+ {
+ "add(a + b + c * d / f + g)",
+ "add((((a + b) + ((c * d) / f)) + g))",
+ },
+ }
+
+ for _, tt := range tests {
+ l := lexer.New(tt.input)
+ p := New(l)
+ program := p.ParseProgram()
+ checkParserErrors(t, p)
+
+ actual := program.String()
+ if actual != tt.expected {
+ t.Errorf("expected=%q, got=%q", tt.expected, actual)
+ }
+ }
+}
+
+func TestBooleanExpression(t *testing.T) {
+ tests := []struct {
+ input string
+ expectedBoolean bool
+ }{
+ {"true;", true},
+ {"false;", false},
+ }
+
+ for _, tt := range tests {
+ l := lexer.New(tt.input)
+ p := New(l)
+ program := p.ParseProgram()
+ checkParserErrors(t, p)
+
+ if len(program.Statements) != 1 {
+ t.Fatalf("program has not enough statements. got=%d",
+ len(program.Statements))
+ }
+
+ stmt, ok := program.Statements[0].(*ast.ExpressionStatement)
+ if !ok {
+ t.Fatalf("program.Statements[0] is not ast.ExpressionStatement. got=%T",
+ program.Statements[0])
+ }
+
+ boolean, ok := stmt.Expression.(*ast.Boolean)
+ if !ok {
+ t.Fatalf("exp not *ast.Boolean. got=%T", stmt.Expression)
+ }
+ if boolean.Value != tt.expectedBoolean {
+ t.Errorf("boolean.Value not %t. got=%t", tt.expectedBoolean,
+ boolean.Value)
+ }
+ }
+}
+
+func TestIfExpression(t *testing.T) {
+ input := `if (x < y) { x }`
+
+ l := lexer.New(input)
+ p := New(l)
+ program := p.ParseProgram()
+ checkParserErrors(t, p)
+
+ if len(program.Statements) != 1 {
+ t.Fatalf("program.Body does not contain %d statements. got=%d\n",
+ 1, len(program.Statements))
+ }
+
+ stmt, ok := program.Statements[0].(*ast.ExpressionStatement)
+ if !ok {
+ t.Fatalf("program.Statements[0] is not ast.ExpressionStatement. got=%T",
+ program.Statements[0])
+ }
+
+ exp, ok := stmt.Expression.(*ast.IfExpression)
+ if !ok {
+ t.Fatalf("stmt.Expression is not ast.IfExpression. got=%T",
+ stmt.Expression)
+ }
+
+ if !testInfixExpression(t, exp.Condition, "x", "<", "y") {
+ return
+ }
+
+ if len(exp.Consequence.Statements) != 1 {
+ t.Errorf("consequence is not 1 statements. got=%d\n",
+ len(exp.Consequence.Statements))
+ }
+
+ consequence, ok := exp.Consequence.Statements[0].(*ast.ExpressionStatement)
+ if !ok {
+ t.Fatalf("Statements[0] is not ast.ExpressionStatement. got=%T",
+ exp.Consequence.Statements[0])
+ }
+
+ if !testIdentifier(t, consequence.Expression, "x") {
+ return
+ }
+
+ if exp.Alternative != nil {
+ t.Errorf("exp.Alternative.Statements was not nil. got=%+v", exp.Alternative)
+ }
+}
+
+func TestIfElseExpression(t *testing.T) {
+ input := `if (x < y) { x } else { y }`
+
+ l := lexer.New(input)
+ p := New(l)
+ program := p.ParseProgram()
+ checkParserErrors(t, p)
+
+ if len(program.Statements) != 1 {
+ t.Fatalf("program.Body does not contain %d statements. got=%d\n",
+ 1, len(program.Statements))
+ }
+
+ stmt, ok := program.Statements[0].(*ast.ExpressionStatement)
+ if !ok {
+ t.Fatalf("program.Statements[0] is not ast.ExpressionStatement. got=%T",
+ program.Statements[0])
+ }
+
+ exp, ok := stmt.Expression.(*ast.IfExpression)
+ if !ok {
+ t.Fatalf("stmt.Expression is not ast.IfExpression. got=%T", stmt.Expression)
+ }
+
+ if !testInfixExpression(t, exp.Condition, "x", "<", "y") {
+ return
+ }
+
+ if len(exp.Consequence.Statements) != 1 {
+ t.Errorf("consequence is not 1 statements. got=%d\n",
+ len(exp.Consequence.Statements))
+ }
+
+ consequence, ok := exp.Consequence.Statements[0].(*ast.ExpressionStatement)
+ if !ok {
+ t.Fatalf("Statements[0] is not ast.ExpressionStatement. got=%T",
+ exp.Consequence.Statements[0])
+ }
+
+ if !testIdentifier(t, consequence.Expression, "x") {
+ return
+ }
+
+ if len(exp.Alternative.Statements) != 1 {
+ t.Errorf("exp.Alternative.Statements does not contain 1 statements. got=%d\n",
+ len(exp.Alternative.Statements))
+ }
+
+ alternative, ok := exp.Alternative.Statements[0].(*ast.ExpressionStatement)
+ if !ok {
+ t.Fatalf("Statements[0] is not ast.ExpressionStatement. got=%T",
+ exp.Alternative.Statements[0])
+ }
+
+ if !testIdentifier(t, alternative.Expression, "y") {
+ return
+ }
+}
+
+func TestFunctionLiteralParsing(t *testing.T) {
+ input := `fn(x, y) { x + y; }`
+
+ l := lexer.New(input)
+ p := New(l)
+ program := p.ParseProgram()
+ checkParserErrors(t, p)
+
+ if len(program.Statements) != 1 {
+ t.Fatalf("program.Body does not contain %d statements. got=%d\n",
+ 1, len(program.Statements))
+ }
+
+ stmt, ok := program.Statements[0].(*ast.ExpressionStatement)
+ if !ok {
+ t.Fatalf("program.Statements[0] is not ast.ExpressionStatement. got=%T",
+ program.Statements[0])
+ }
+
+ function, ok := stmt.Expression.(*ast.FunctionLiteral)
+ if !ok {
+ t.Fatalf("stmt.Expression is not ast.FunctionLiteral. got=%T",
+ stmt.Expression)
+ }
+
+ if len(function.Parameters) != 2 {
+ t.Fatalf("function literal parameters wrong. want 2, got=%d\n",
+ len(function.Parameters))
+ }
+
+ testLiteralExpression(t, function.Parameters[0], "x")
+ testLiteralExpression(t, function.Parameters[1], "y")
+
+ if len(function.Body.Statements) != 1 {
+ t.Fatalf("function.Body.Statements has not 1 statements. got=%d\n",
+ len(function.Body.Statements))
+ }
+
+ bodyStmt, ok := function.Body.Statements[0].(*ast.ExpressionStatement)
+ if !ok {
+ t.Fatalf("function body stmt is not ast.ExpressionStatement. got=%T",
+ function.Body.Statements[0])
+ }
+
+ testInfixExpression(t, bodyStmt.Expression, "x", "+", "y")
+}
+
+func TestFunctionParameterParsing(t *testing.T) {
+ tests := []struct {
+ input string
+ expectedParams []string
+ }{
+ {input: "fn() {};", expectedParams: []string{}},
+ {input: "fn(x) {};", expectedParams: []string{"x"}},
+ {input: "fn(x, y, z) {};", expectedParams: []string{"x", "y", "z"}},
+ }
+
+ for _, tt := range tests {
+ l := lexer.New(tt.input)
+ p := New(l)
+ program := p.ParseProgram()
+ checkParserErrors(t, p)
+
+ stmt := program.Statements[0].(*ast.ExpressionStatement)
+ function := stmt.Expression.(*ast.FunctionLiteral)
+
+ if len(function.Parameters) != len(tt.expectedParams) {
+ t.Errorf("length parameters wrong. want %d, got=%d\n",
+ len(tt.expectedParams), len(function.Parameters))
+ }
+
+ for i, ident := range tt.expectedParams {
+ testLiteralExpression(t, function.Parameters[i], ident)
+ }
+ }
+}
+
+func TestCallExpressionParsing(t *testing.T) {
+ input := "add(1, 2 * 3, 4 + 5);"
+
+ l := lexer.New(input)
+ p := New(l)
+ program := p.ParseProgram()
+ checkParserErrors(t, p)
+
+ if len(program.Statements) != 1 {
+ t.Fatalf("program.Statements does not contain %d statements. got=%d\n",
+ 1, len(program.Statements))
+ }
+
+ stmt, ok := program.Statements[0].(*ast.ExpressionStatement)
+ if !ok {
+ t.Fatalf("stmt is not ast.ExpressionStatement. got=%T",
+ program.Statements[0])
+ }
+
+ exp, ok := stmt.Expression.(*ast.CallExpression)
+ if !ok {
+ t.Fatalf("stmt.Expression is not ast.CallExpression. got=%T",
+ stmt.Expression)
+ }
+
+ if !testIdentifier(t, exp.Function, "add") {
+ return
+ }
+
+ if len(exp.Arguments) != 3 {
+ t.Fatalf("wrong length of arguments. got=%d", len(exp.Arguments))
+ }
+
+ testLiteralExpression(t, exp.Arguments[0], 1)
+ testInfixExpression(t, exp.Arguments[1], 2, "*", 3)
+ testInfixExpression(t, exp.Arguments[2], 4, "+", 5)
+}
+
+func TestCallExpressionParameterParsing(t *testing.T) {
+ tests := []struct {
+ input string
+ expectedIdent string
+ expectedArgs []string
+ }{
+ {
+ input: "add();",
+ expectedIdent: "add",
+ expectedArgs: []string{},
+ },
+ {
+ input: "add(1);",
+ expectedIdent: "add",
+ expectedArgs: []string{"1"},
+ },
+ {
+ input: "add(1, 2 * 3, 4 + 5);",
+ expectedIdent: "add",
+ expectedArgs: []string{"1", "(2 * 3)", "(4 + 5)"},
+ },
+ }
+
+ for _, tt := range tests {
+ l := lexer.New(tt.input)
+ p := New(l)
+ program := p.ParseProgram()
+ checkParserErrors(t, p)
+
+ stmt := program.Statements[0].(*ast.ExpressionStatement)
+ exp, ok := stmt.Expression.(*ast.CallExpression)
+ if !ok {
+ t.Fatalf("stmt.Expression is not ast.CallExpression. got=%T",
+ stmt.Expression)
+ }
+
+ if !testIdentifier(t, exp.Function, tt.expectedIdent) {
+ return
+ }
+
+ if len(exp.Arguments) != len(tt.expectedArgs) {
+ t.Fatalf("wrong number of arguments. want=%d, got=%d",
+ len(tt.expectedArgs), len(exp.Arguments))
+ }
+
+ for i, arg := range tt.expectedArgs {
+ if exp.Arguments[i].String() != arg {
+ t.Errorf("argument %d wrong. want=%q, got=%q", i,
+ arg, exp.Arguments[i].String())
+ }
+ }
+ }
+}
+
+func testLetStatement(t *testing.T, s ast.Statement, name string) bool {
+ if s.TokenLiteral() != "let" {
+ t.Errorf("s.TokenLiteral not 'let'. got=%q", s.TokenLiteral())
+ return false
+ }
+
+ letStmt, ok := s.(*ast.LetStatement)
+ if !ok {
+ t.Errorf("s not *ast.LetStatement. got=%T", s)
+ return false
+ }
+
+ if letStmt.Name.Value != name {
+ t.Errorf("letStmt.Name.Value not '%s'. got=%s", name, letStmt.Name.Value)
+ return false
+ }
+
+ if letStmt.Name.TokenLiteral() != name {
+ t.Errorf("s.Name not '%s'. got=%s", name, letStmt.Name)
+ return false
+ }
+
+ return true
+}
+
+func testInfixExpression(t *testing.T, exp ast.Expression, left interface{},
+ operator string, right interface{}) bool {
+
+ opExp, ok := exp.(*ast.InfixExpression)
+ if !ok {
+ t.Errorf("exp is not ast.OperatorExpression. got=%T(%s)", exp, exp)
+ return false
+ }
+
+ if !testLiteralExpression(t, opExp.Left, left) {
+ return false
+ }
+
+ if opExp.Operator != operator {
+ t.Errorf("exp.Operator is not '%s'. got=%q", operator, opExp.Operator)
+ return false
+ }
+
+ if !testLiteralExpression(t, opExp.Right, right) {
+ return false
+ }
+
+ return true
+}
+
+func testLiteralExpression(
+ t *testing.T,
+ exp ast.Expression,
+ expected interface{},
+) bool {
+ switch v := expected.(type) {
+ case int:
+ return testIntegerLiteral(t, exp, int64(v))
+ case int64:
+ return testIntegerLiteral(t, exp, v)
+ case string:
+ return testIdentifier(t, exp, v)
+ case bool:
+ return testBooleanLiteral(t, exp, v)
+ }
+ t.Errorf("type of exp not handled. got=%T", exp)
+ return false
+}
+
+func testIntegerLiteral(t *testing.T, il ast.Expression, value int64) bool {
+ integ, ok := il.(*ast.IntegerLiteral)
+ if !ok {
+ t.Errorf("il not *ast.IntegerLiteral. got=%T", il)
+ return false
+ }
+
+ if integ.Value != value {
+ t.Errorf("integ.Value not %d. got=%d", value, integ.Value)
+ return false
+ }
+
+ if integ.TokenLiteral() != fmt.Sprintf("%d", value) {
+ t.Errorf("integ.TokenLiteral not %d. got=%s", value,
+ integ.TokenLiteral())
+ return false
+ }
+
+ return true
+}
+
+func testIdentifier(t *testing.T, exp ast.Expression, value string) bool {
+ ident, ok := exp.(*ast.Identifier)
+ if !ok {
+ t.Errorf("exp not *ast.Identifier. got=%T", exp)
+ return false
+ }
+
+ if ident.Value != value {
+ t.Errorf("ident.Value not %s. got=%s", value, ident.Value)
+ return false
+ }
+
+ if ident.TokenLiteral() != value {
+ t.Errorf("ident.TokenLiteral not %s. got=%s", value,
+ ident.TokenLiteral())
+ return false
+ }
+
+ return true
+}
+
+func testBooleanLiteral(t *testing.T, exp ast.Expression, value bool) bool {
+ bo, ok := exp.(*ast.Boolean)
+ if !ok {
+ t.Errorf("exp not *ast.Boolean. got=%T", exp)
+ return false
+ }
+
+ if bo.Value != value {
+ t.Errorf("bo.Value not %t. got=%t", value, bo.Value)
+ return false
+ }
+
+ if bo.TokenLiteral() != fmt.Sprintf("%t", value) {
+ t.Errorf("bo.TokenLiteral not %t. got=%s",
+ value, bo.TokenLiteral())
+ return false
+ }
+
+ return true
+}
+
+func checkParserErrors(t *testing.T, p *Parser) {
+ errors := p.Errors()
+ if len(errors) == 0 {
+ return
+ }
+
+ t.Errorf("parser has %d errors", len(errors))
+ for _, msg := range errors {
+ t.Errorf("parser error: %q", msg)
+ }
+ t.FailNow()
+}