exp/template: split the parse tree into a separate package exp/template/parse
Mostly a mechanical change, with a few cleanups to make the split easier.
The external interface to exp/template is unaffected.
In another round I will play with the function map setup to see if I can
avoid exposing reflect across the boundary, but that will require some
structural changes I did not want to mix into this CL.
R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/4849049
diff --git a/src/pkg/Makefile b/src/pkg/Makefile
index e09b545..c824f50 100644
--- a/src/pkg/Makefile
+++ b/src/pkg/Makefile
@@ -83,6 +83,7 @@
exp/norm\
exp/regexp/syntax\
exp/template\
+ exp/template/parse\
expvar\
flag\
fmt\
diff --git a/src/pkg/exp/template/Makefile b/src/pkg/exp/template/Makefile
index 988791f..06df9b6 100644
--- a/src/pkg/exp/template/Makefile
+++ b/src/pkg/exp/template/Makefile
@@ -9,7 +9,6 @@
exec.go\
funcs.go\
helper.go\
- lex.go\
parse.go\
set.go\
diff --git a/src/pkg/exp/template/exec.go b/src/pkg/exp/template/exec.go
index e500465..6fc1da4 100644
--- a/src/pkg/exp/template/exec.go
+++ b/src/pkg/exp/template/exec.go
@@ -5,10 +5,12 @@
package template
import (
+ "exp/template/parse"
"fmt"
"io"
"os"
"reflect"
+ "runtime"
"strings"
)
@@ -63,7 +65,7 @@
// errorf formats the error and terminates processing.
func (s *state) errorf(format string, args ...interface{}) {
- format = fmt.Sprintf("template: %s:%d: %s", s.tmpl.name, s.line, format)
+ format = fmt.Sprintf("template: %s:%d: %s", s.tmpl.Name(), s.line, format)
panic(fmt.Errorf(format, args...))
}
@@ -72,10 +74,22 @@
s.errorf("%s", err)
}
+// errRecover is the handler that turns panics into returns from the top
+// level of Parse.
+func errRecover(errp *os.Error) {
+ e := recover()
+ if e != nil {
+ if _, ok := e.(runtime.Error); ok {
+ panic(e)
+ }
+ *errp = e.(os.Error)
+ }
+}
+
// Execute applies a parsed template to the specified data object,
// writing the output to wr.
func (t *Template) Execute(wr io.Writer, data interface{}) (err os.Error) {
- defer t.recover(&err)
+ defer errRecover(&err)
value := reflect.ValueOf(data)
state := &state{
tmpl: t,
@@ -83,45 +97,45 @@
line: 1,
vars: []variable{{"$", value}},
}
- if t.root == nil {
+ if t.Root == nil {
state.errorf("must be parsed before execution")
}
- state.walk(value, t.root)
+ state.walk(value, t.Root)
return
}
// Walk functions step through the major pieces of the template structure,
// generating output as they go.
-func (s *state) walk(dot reflect.Value, n node) {
+func (s *state) walk(dot reflect.Value, n parse.Node) {
switch n := n.(type) {
- case *actionNode:
- s.line = n.line
+ case *parse.ActionNode:
+ s.line = n.Line
// Do not pop variables so they persist until next end.
// Also, if the action declares variables, don't print the result.
- val := s.evalPipeline(dot, n.pipe)
- if len(n.pipe.decl) == 0 {
+ val := s.evalPipeline(dot, n.Pipe)
+ if len(n.Pipe.Decl) == 0 {
s.printValue(n, val)
}
- case *ifNode:
- s.line = n.line
- s.walkIfOrWith(nodeIf, dot, n.pipe, n.list, n.elseList)
- case *listNode:
- for _, node := range n.nodes {
+ case *parse.IfNode:
+ s.line = n.Line
+ s.walkIfOrWith(parse.NodeIf, dot, n.Pipe, n.List, n.ElseList)
+ case *parse.ListNode:
+ for _, node := range n.Nodes {
s.walk(dot, node)
}
- case *rangeNode:
- s.line = n.line
+ case *parse.RangeNode:
+ s.line = n.Line
s.walkRange(dot, n)
- case *templateNode:
- s.line = n.line
+ case *parse.TemplateNode:
+ s.line = n.Line
s.walkTemplate(dot, n)
- case *textNode:
- if _, err := s.wr.Write(n.text); err != nil {
+ case *parse.TextNode:
+ if _, err := s.wr.Write(n.Text); err != nil {
s.error(err)
}
- case *withNode:
- s.line = n.line
- s.walkIfOrWith(nodeWith, dot, n.pipe, n.list, n.elseList)
+ case *parse.WithNode:
+ s.line = n.Line
+ s.walkIfOrWith(parse.NodeWith, dot, n.Pipe, n.List, n.ElseList)
default:
s.errorf("unknown node: %s", n)
}
@@ -129,7 +143,7 @@
// walkIfOrWith walks an 'if' or 'with' node. The two control structures
// are identical in behavior except that 'with' sets dot.
-func (s *state) walkIfOrWith(typ nodeType, dot reflect.Value, pipe *pipeNode, list, elseList *listNode) {
+func (s *state) walkIfOrWith(typ parse.NodeType, dot reflect.Value, pipe *parse.PipeNode, list, elseList *parse.ListNode) {
defer s.pop(s.mark())
val := s.evalPipeline(dot, pipe)
truth, ok := isTrue(val)
@@ -137,7 +151,7 @@
s.errorf("if/with can't use value of type %T", val.Interface())
}
if truth {
- if typ == nodeWith {
+ if typ == parse.NodeWith {
s.walk(val, list)
} else {
s.walk(dot, list)
@@ -171,9 +185,9 @@
return truth, true
}
-func (s *state) walkRange(dot reflect.Value, r *rangeNode) {
+func (s *state) walkRange(dot reflect.Value, r *parse.RangeNode) {
defer s.pop(s.mark())
- val, _ := indirect(s.evalPipeline(dot, r.pipe))
+ val, _ := indirect(s.evalPipeline(dot, r.Pipe))
// mark top of stack before any variables in the body are pushed.
mark := s.mark()
switch val.Kind() {
@@ -184,14 +198,14 @@
for i := 0; i < val.Len(); i++ {
elem := val.Index(i)
// Set top var (lexically the second if there are two) to the element.
- if len(r.pipe.decl) > 0 {
+ if len(r.Pipe.Decl) > 0 {
s.setVar(1, elem)
}
// Set next var (lexically the first if there are two) to the index.
- if len(r.pipe.decl) > 1 {
+ if len(r.Pipe.Decl) > 1 {
s.setVar(2, reflect.ValueOf(i))
}
- s.walk(elem, r.list)
+ s.walk(elem, r.List)
s.pop(mark)
}
return
@@ -202,41 +216,41 @@
for _, key := range val.MapKeys() {
elem := val.MapIndex(key)
// Set top var (lexically the second if there are two) to the element.
- if len(r.pipe.decl) > 0 {
+ if len(r.Pipe.Decl) > 0 {
s.setVar(1, elem)
}
// Set next var (lexically the first if there are two) to the key.
- if len(r.pipe.decl) > 1 {
+ if len(r.Pipe.Decl) > 1 {
s.setVar(2, key)
}
- s.walk(elem, r.list)
+ s.walk(elem, r.List)
s.pop(mark)
}
return
default:
s.errorf("range can't iterate over value of type %T", val.Interface())
}
- if r.elseList != nil {
- s.walk(dot, r.elseList)
+ if r.ElseList != nil {
+ s.walk(dot, r.ElseList)
}
}
-func (s *state) walkTemplate(dot reflect.Value, t *templateNode) {
+func (s *state) walkTemplate(dot reflect.Value, t *parse.TemplateNode) {
set := s.tmpl.set
if set == nil {
- s.errorf("no set defined in which to invoke template named %q", t.name)
+ s.errorf("no set defined in which to invoke template named %q", t.Name)
}
- tmpl := set.tmpl[t.name]
+ tmpl := set.tmpl[t.Name]
if tmpl == nil {
- s.errorf("template %q not in set", t.name)
+ s.errorf("template %q not in set", t.Name)
}
// Variables declared by the pipeline persist.
- dot = s.evalPipeline(dot, t.pipe)
+ dot = s.evalPipeline(dot, t.Pipe)
newState := *s
newState.tmpl = tmpl
// No dynamic scoping: template invocations inherit no variables.
newState.vars = []variable{{"$", dot}}
- newState.walk(dot, tmpl.root)
+ newState.walk(dot, tmpl.Root)
}
// Eval functions evaluate pipelines, commands, and their elements and extract
@@ -247,50 +261,50 @@
// pipeline has a variable declaration, the variable will be pushed on the
// stack. Callers should therefore pop the stack after they are finished
// executing commands depending on the pipeline value.
-func (s *state) evalPipeline(dot reflect.Value, pipe *pipeNode) (value reflect.Value) {
+func (s *state) evalPipeline(dot reflect.Value, pipe *parse.PipeNode) (value reflect.Value) {
if pipe == nil {
return
}
- for _, cmd := range pipe.cmds {
+ for _, cmd := range pipe.Cmds {
value = s.evalCommand(dot, cmd, value) // previous value is this one's final arg.
// If the object has type interface{}, dig down one level to the thing inside.
if value.Kind() == reflect.Interface && value.Type().NumMethod() == 0 {
value = reflect.ValueOf(value.Interface()) // lovely!
}
}
- for _, variable := range pipe.decl {
- s.push(variable.ident[0], value)
+ for _, variable := range pipe.Decl {
+ s.push(variable.Ident[0], value)
}
return value
}
-func (s *state) notAFunction(args []node, final reflect.Value) {
+func (s *state) notAFunction(args []parse.Node, final reflect.Value) {
if len(args) > 1 || final.IsValid() {
s.errorf("can't give argument to non-function %s", args[0])
}
}
-func (s *state) evalCommand(dot reflect.Value, cmd *commandNode, final reflect.Value) reflect.Value {
- firstWord := cmd.args[0]
+func (s *state) evalCommand(dot reflect.Value, cmd *parse.CommandNode, final reflect.Value) reflect.Value {
+ firstWord := cmd.Args[0]
switch n := firstWord.(type) {
- case *fieldNode:
- return s.evalFieldNode(dot, n, cmd.args, final)
- case *identifierNode:
+ case *parse.FieldNode:
+ return s.evalFieldNode(dot, n, cmd.Args, final)
+ case *parse.IdentifierNode:
// Must be a function.
- return s.evalFunction(dot, n.ident, cmd.args, final)
- case *variableNode:
- return s.evalVariableNode(dot, n, cmd.args, final)
+ return s.evalFunction(dot, n.Ident, cmd.Args, final)
+ case *parse.VariableNode:
+ return s.evalVariableNode(dot, n, cmd.Args, final)
}
- s.notAFunction(cmd.args, final)
+ s.notAFunction(cmd.Args, final)
switch word := firstWord.(type) {
- case *boolNode:
- return reflect.ValueOf(word.true)
- case *dotNode:
+ case *parse.BoolNode:
+ return reflect.ValueOf(word.True)
+ case *parse.DotNode:
return dot
- case *numberNode:
+ case *parse.NumberNode:
return s.idealConstant(word)
- case *stringNode:
- return reflect.ValueOf(word.text)
+ case *parse.StringNode:
+ return reflect.ValueOf(word.Text)
}
s.errorf("can't evaluate command %q", firstWord)
panic("not reached")
@@ -300,44 +314,44 @@
// we don't know the type. In that case, the syntax of the number tells us
// its type, and we use Go rules to resolve. Note there is no such thing as
// a uint ideal constant in this situation - the value must be of int type.
-func (s *state) idealConstant(constant *numberNode) reflect.Value {
+func (s *state) idealConstant(constant *parse.NumberNode) reflect.Value {
// These are ideal constants but we don't know the type
// and we have no context. (If it was a method argument,
// we'd know what we need.) The syntax guides us to some extent.
switch {
- case constant.isComplex:
- return reflect.ValueOf(constant.complex128) // incontrovertible.
- case constant.isFloat && strings.IndexAny(constant.text, ".eE") >= 0:
- return reflect.ValueOf(constant.float64)
- case constant.isInt:
- n := int(constant.int64)
- if int64(n) != constant.int64 {
- s.errorf("%s overflows int", constant.text)
+ case constant.IsComplex:
+ return reflect.ValueOf(constant.Complex128) // incontrovertible.
+ case constant.IsFloat && strings.IndexAny(constant.Text, ".eE") >= 0:
+ return reflect.ValueOf(constant.Float64)
+ case constant.IsInt:
+ n := int(constant.Int64)
+ if int64(n) != constant.Int64 {
+ s.errorf("%s overflows int", constant.Text)
}
return reflect.ValueOf(n)
- case constant.isUint:
- s.errorf("%s overflows int", constant.text)
+ case constant.IsUint:
+ s.errorf("%s overflows int", constant.Text)
}
return zero
}
-func (s *state) evalFieldNode(dot reflect.Value, field *fieldNode, args []node, final reflect.Value) reflect.Value {
- return s.evalFieldChain(dot, dot, field.ident, args, final)
+func (s *state) evalFieldNode(dot reflect.Value, field *parse.FieldNode, args []parse.Node, final reflect.Value) reflect.Value {
+ return s.evalFieldChain(dot, dot, field.Ident, args, final)
}
-func (s *state) evalVariableNode(dot reflect.Value, v *variableNode, args []node, final reflect.Value) reflect.Value {
+func (s *state) evalVariableNode(dot reflect.Value, v *parse.VariableNode, args []parse.Node, final reflect.Value) reflect.Value {
// $x.Field has $x as the first ident, Field as the second. Eval the var, then the fields.
- value := s.varValue(v.ident[0])
- if len(v.ident) == 1 {
+ value := s.varValue(v.Ident[0])
+ if len(v.Ident) == 1 {
return value
}
- return s.evalFieldChain(dot, value, v.ident[1:], args, final)
+ return s.evalFieldChain(dot, value, v.Ident[1:], args, final)
}
// evalFieldChain evaluates .X.Y.Z possibly followed by arguments.
// dot is the environment in which to evaluate arguments, while
// receiver is the value being walked along the chain.
-func (s *state) evalFieldChain(dot, receiver reflect.Value, ident []string, args []node, final reflect.Value) reflect.Value {
+func (s *state) evalFieldChain(dot, receiver reflect.Value, ident []string, args []parse.Node, final reflect.Value) reflect.Value {
n := len(ident)
for i := 0; i < n-1; i++ {
receiver = s.evalField(dot, ident[i], nil, zero, receiver)
@@ -346,7 +360,7 @@
return s.evalField(dot, ident[n-1], args, final, receiver)
}
-func (s *state) evalFunction(dot reflect.Value, name string, args []node, final reflect.Value) reflect.Value {
+func (s *state) evalFunction(dot reflect.Value, name string, args []parse.Node, final reflect.Value) reflect.Value {
function, ok := findFunction(name, s.tmpl, s.tmpl.set)
if !ok {
s.errorf("%q is not a defined function", name)
@@ -357,7 +371,7 @@
// evalField evaluates an expression like (.Field) or (.Field arg1 arg2).
// The 'final' argument represents the return value from the preceding
// value of the pipeline, if any.
-func (s *state) evalField(dot reflect.Value, fieldName string, args []node, final, receiver reflect.Value) reflect.Value {
+func (s *state) evalField(dot reflect.Value, fieldName string, args []parse.Node, final, receiver reflect.Value) reflect.Value {
if !receiver.IsValid() {
return zero
}
@@ -411,7 +425,7 @@
// evalCall executes a function or method call. If it's a method, fun already has the receiver bound, so
// it looks just like a function call. The arg list, if non-nil, includes (in the manner of the shell), arg[0]
// as the function itself.
-func (s *state) evalCall(dot, fun reflect.Value, name string, args []node, final reflect.Value) reflect.Value {
+func (s *state) evalCall(dot, fun reflect.Value, name string, args []parse.Node, final reflect.Value) reflect.Value {
if args != nil {
args = args[1:] // Zeroth arg is function name/node; not passed to function.
}
@@ -469,13 +483,13 @@
return value
}
-func (s *state) evalArg(dot reflect.Value, typ reflect.Type, n node) reflect.Value {
+func (s *state) evalArg(dot reflect.Value, typ reflect.Type, n parse.Node) reflect.Value {
switch arg := n.(type) {
- case *dotNode:
+ case *parse.DotNode:
return s.validateType(dot, typ)
- case *fieldNode:
- return s.validateType(s.evalFieldNode(dot, arg, []node{n}, zero), typ)
- case *variableNode:
+ case *parse.FieldNode:
+ return s.validateType(s.evalFieldNode(dot, arg, []parse.Node{n}, zero), typ)
+ case *parse.VariableNode:
return s.validateType(s.evalVariableNode(dot, arg, nil, zero), typ)
}
switch typ.Kind() {
@@ -500,81 +514,81 @@
panic("not reached")
}
-func (s *state) evalBool(typ reflect.Type, n node) reflect.Value {
- if n, ok := n.(*boolNode); ok {
+func (s *state) evalBool(typ reflect.Type, n parse.Node) reflect.Value {
+ if n, ok := n.(*parse.BoolNode); ok {
value := reflect.New(typ).Elem()
- value.SetBool(n.true)
+ value.SetBool(n.True)
return value
}
s.errorf("expected bool; found %s", n)
panic("not reached")
}
-func (s *state) evalString(typ reflect.Type, n node) reflect.Value {
- if n, ok := n.(*stringNode); ok {
+func (s *state) evalString(typ reflect.Type, n parse.Node) reflect.Value {
+ if n, ok := n.(*parse.StringNode); ok {
value := reflect.New(typ).Elem()
- value.SetString(n.text)
+ value.SetString(n.Text)
return value
}
s.errorf("expected string; found %s", n)
panic("not reached")
}
-func (s *state) evalInteger(typ reflect.Type, n node) reflect.Value {
- if n, ok := n.(*numberNode); ok && n.isInt {
+func (s *state) evalInteger(typ reflect.Type, n parse.Node) reflect.Value {
+ if n, ok := n.(*parse.NumberNode); ok && n.IsInt {
value := reflect.New(typ).Elem()
- value.SetInt(n.int64)
+ value.SetInt(n.Int64)
return value
}
s.errorf("expected integer; found %s", n)
panic("not reached")
}
-func (s *state) evalUnsignedInteger(typ reflect.Type, n node) reflect.Value {
- if n, ok := n.(*numberNode); ok && n.isUint {
+func (s *state) evalUnsignedInteger(typ reflect.Type, n parse.Node) reflect.Value {
+ if n, ok := n.(*parse.NumberNode); ok && n.IsUint {
value := reflect.New(typ).Elem()
- value.SetUint(n.uint64)
+ value.SetUint(n.Uint64)
return value
}
s.errorf("expected unsigned integer; found %s", n)
panic("not reached")
}
-func (s *state) evalFloat(typ reflect.Type, n node) reflect.Value {
- if n, ok := n.(*numberNode); ok && n.isFloat {
+func (s *state) evalFloat(typ reflect.Type, n parse.Node) reflect.Value {
+ if n, ok := n.(*parse.NumberNode); ok && n.IsFloat {
value := reflect.New(typ).Elem()
- value.SetFloat(n.float64)
+ value.SetFloat(n.Float64)
return value
}
s.errorf("expected float; found %s", n)
panic("not reached")
}
-func (s *state) evalComplex(typ reflect.Type, n node) reflect.Value {
- if n, ok := n.(*numberNode); ok && n.isComplex {
+func (s *state) evalComplex(typ reflect.Type, n parse.Node) reflect.Value {
+ if n, ok := n.(*parse.NumberNode); ok && n.IsComplex {
value := reflect.New(typ).Elem()
- value.SetComplex(n.complex128)
+ value.SetComplex(n.Complex128)
return value
}
s.errorf("expected complex; found %s", n)
panic("not reached")
}
-func (s *state) evalEmptyInterface(dot reflect.Value, n node) reflect.Value {
+func (s *state) evalEmptyInterface(dot reflect.Value, n parse.Node) reflect.Value {
switch n := n.(type) {
- case *boolNode:
- return reflect.ValueOf(n.true)
- case *dotNode:
+ case *parse.BoolNode:
+ return reflect.ValueOf(n.True)
+ case *parse.DotNode:
return dot
- case *fieldNode:
+ case *parse.FieldNode:
return s.evalFieldNode(dot, n, nil, zero)
- case *identifierNode:
- return s.evalFunction(dot, n.ident, nil, zero)
- case *numberNode:
+ case *parse.IdentifierNode:
+ return s.evalFunction(dot, n.Ident, nil, zero)
+ case *parse.NumberNode:
return s.idealConstant(n)
- case *stringNode:
- return reflect.ValueOf(n.text)
- case *variableNode:
+ case *parse.StringNode:
+ return reflect.ValueOf(n.Text)
+ case *parse.VariableNode:
return s.evalVariableNode(dot, n, nil, zero)
}
s.errorf("can't handle assignment of %s to empty interface argument", n)
@@ -598,7 +612,7 @@
// printValue writes the textual representation of the value to the output of
// the template.
-func (s *state) printValue(n node, v reflect.Value) {
+func (s *state) printValue(n parse.Node, v reflect.Value) {
if !v.IsValid() {
fmt.Fprint(s.wr, "<no value>")
return
diff --git a/src/pkg/exp/template/exec_test.go b/src/pkg/exp/template/exec_test.go
index 50eefc3..415f170 100644
--- a/src/pkg/exp/template/exec_test.go
+++ b/src/pkg/exp/template/exec_test.go
@@ -6,6 +6,7 @@
import (
"bytes"
+ "flag"
"fmt"
"os"
"reflect"
@@ -14,6 +15,8 @@
"testing"
)
+var debug = flag.Bool("debug", false, "show the errors produced by the tests")
+
// T has lots of interesting pieces to use to test execution.
type T struct {
// Basics
diff --git a/src/pkg/exp/template/funcs.go b/src/pkg/exp/template/funcs.go
index 5e912e0..0fbc0e4 100644
--- a/src/pkg/exp/template/funcs.go
+++ b/src/pkg/exp/template/funcs.go
@@ -22,7 +22,7 @@
// during execution, execution terminates and Execute returns an error.
type FuncMap map[string]interface{}
-var funcs = map[string]reflect.Value{
+var builtins = map[string]reflect.Value{
"and": reflect.ValueOf(and),
"html": reflect.ValueOf(HTMLEscaper),
"index": reflect.ValueOf(index),
@@ -73,7 +73,7 @@
return fn, true
}
}
- if fn := funcs[name]; fn.IsValid() {
+ if fn := builtins[name]; fn.IsValid() {
return fn, true
}
return reflect.Value{}, false
diff --git a/src/pkg/exp/template/parse.go b/src/pkg/exp/template/parse.go
index 8a0b51e..9cc48c4 100644
--- a/src/pkg/exp/template/parse.go
+++ b/src/pkg/exp/template/parse.go
@@ -5,512 +5,22 @@
package template
import (
- "bytes"
- "fmt"
+ "exp/template/parse"
"os"
"reflect"
- "runtime"
- "strconv"
- "strings"
- "unicode"
)
// Template is the representation of a parsed template.
type Template struct {
- name string
- root *listNode
+ name string
+ *parse.Tree
funcs map[string]reflect.Value
set *Set // can be nil.
- // Parsing only; cleared after parse.
- parseSet *Set // for function lookup during parse.
- lex *lexer
- token [2]item // two-token lookahead for parser.
- peekCount int
- vars []string // variables defined at the moment.
}
// Name returns the name of the template.
func (t *Template) Name() string {
- return t.name
-}
-
-// next returns the next token.
-func (t *Template) next() item {
- if t.peekCount > 0 {
- t.peekCount--
- } else {
- t.token[0] = t.lex.nextItem()
- }
- return t.token[t.peekCount]
-}
-
-// backup backs the input stream up one token.
-func (t *Template) backup() {
- t.peekCount++
-}
-
-// backup2 backs the input stream up two tokens
-func (t *Template) backup2(t1 item) {
- t.token[1] = t1
- t.peekCount = 2
-}
-
-// peek returns but does not consume the next token.
-func (t *Template) peek() item {
- if t.peekCount > 0 {
- return t.token[t.peekCount-1]
- }
- t.peekCount = 1
- t.token[0] = t.lex.nextItem()
- return t.token[0]
-}
-
-// A node is an element in the parse tree. The interface is trivial.
-type node interface {
- typ() nodeType
- String() string
-}
-
-type nodeType int
-
-func (t nodeType) typ() nodeType {
- return t
-}
-
-const (
- nodeText nodeType = iota
- nodeAction
- nodeCommand
- nodeDot
- nodeElse
- nodeEnd
- nodeField
- nodeIdentifier
- nodeIf
- nodeList
- nodeNumber
- nodePipe
- nodeRange
- nodeString
- nodeTemplate
- nodeVariable
- nodeWith
-)
-
-// Nodes.
-
-// listNode holds a sequence of nodes.
-type listNode struct {
- nodeType
- nodes []node
-}
-
-func newList() *listNode {
- return &listNode{nodeType: nodeList}
-}
-
-func (l *listNode) append(n node) {
- l.nodes = append(l.nodes, n)
-}
-
-func (l *listNode) String() string {
- b := new(bytes.Buffer)
- fmt.Fprint(b, "[")
- for _, n := range l.nodes {
- fmt.Fprint(b, n)
- }
- fmt.Fprint(b, "]")
- return b.String()
-}
-
-// textNode holds plain text.
-type textNode struct {
- nodeType
- text []byte
-}
-
-func newText(text string) *textNode {
- return &textNode{nodeType: nodeText, text: []byte(text)}
-}
-
-func (t *textNode) String() string {
- return fmt.Sprintf("(text: %q)", t.text)
-}
-
-// pipeNode holds a pipeline with optional declaration
-type pipeNode struct {
- nodeType
- line int
- decl []*variableNode
- cmds []*commandNode
-}
-
-func newPipeline(line int, decl []*variableNode) *pipeNode {
- return &pipeNode{nodeType: nodePipe, line: line, decl: decl}
-}
-
-func (p *pipeNode) append(command *commandNode) {
- p.cmds = append(p.cmds, command)
-}
-
-func (p *pipeNode) String() string {
- if p.decl != nil {
- return fmt.Sprintf("%v := %v", p.decl, p.cmds)
- }
- return fmt.Sprintf("%v", p.cmds)
-}
-
-// actionNode holds an action (something bounded by delimiters).
-type actionNode struct {
- nodeType
- line int
- pipe *pipeNode
-}
-
-func newAction(line int, pipe *pipeNode) *actionNode {
- return &actionNode{nodeType: nodeAction, line: line, pipe: pipe}
-}
-
-func (a *actionNode) String() string {
- return fmt.Sprintf("(action: %v)", a.pipe)
-}
-
-// commandNode holds a command (a pipeline inside an evaluating action).
-type commandNode struct {
- nodeType
- args []node // identifier, string, or number
-}
-
-func newCommand() *commandNode {
- return &commandNode{nodeType: nodeCommand}
-}
-
-func (c *commandNode) append(arg node) {
- c.args = append(c.args, arg)
-}
-
-func (c *commandNode) String() string {
- return fmt.Sprintf("(command: %v)", c.args)
-}
-
-// identifierNode holds an identifier.
-type identifierNode struct {
- nodeType
- ident string
-}
-
-func newIdentifier(ident string) *identifierNode {
- return &identifierNode{nodeType: nodeIdentifier, ident: ident}
-}
-
-func (i *identifierNode) String() string {
- return fmt.Sprintf("I=%s", i.ident)
-}
-
-// variableNode holds a variable.
-type variableNode struct {
- nodeType
- ident []string
-}
-
-func newVariable(ident string) *variableNode {
- return &variableNode{nodeType: nodeVariable, ident: strings.Split(ident, ".")}
-}
-
-func (v *variableNode) String() string {
- return fmt.Sprintf("V=%s", v.ident)
-}
-
-// dotNode holds the special identifier '.'. It is represented by a nil pointer.
-type dotNode bool
-
-func newDot() *dotNode {
- return nil
-}
-
-func (d *dotNode) typ() nodeType {
- return nodeDot
-}
-
-func (d *dotNode) String() string {
- return "{{<.>}}"
-}
-
-// fieldNode holds a field (identifier starting with '.').
-// The names may be chained ('.x.y').
-// The period is dropped from each ident.
-type fieldNode struct {
- nodeType
- ident []string
-}
-
-func newField(ident string) *fieldNode {
- return &fieldNode{nodeType: nodeField, ident: strings.Split(ident[1:], ".")} // [1:] to drop leading period
-}
-
-func (f *fieldNode) String() string {
- return fmt.Sprintf("F=%s", f.ident)
-}
-
-// boolNode holds a boolean constant.
-type boolNode struct {
- nodeType
- true bool
-}
-
-func newBool(true bool) *boolNode {
- return &boolNode{nodeType: nodeString, true: true}
-}
-
-func (b *boolNode) String() string {
- if b.true {
- return fmt.Sprintf("B=true")
- }
- return fmt.Sprintf("B=false")
-}
-
-// numberNode holds a number, signed or unsigned integer, floating, or complex.
-// The value is parsed and stored under all the types that can represent the value.
-// This simulates in a small amount of code the behavior of Go's ideal constants.
-type numberNode struct {
- nodeType
- isInt bool // number has an integral value
- isUint bool // number has an unsigned integral value
- isFloat bool // number has a floating-point value
- isComplex bool // number is complex
- int64 // the signed integer value
- uint64 // the unsigned integer value
- float64 // the floating-point value
- complex128 // the complex value
- text string
-}
-
-func newNumber(text string, typ itemType) (*numberNode, os.Error) {
- n := &numberNode{nodeType: nodeNumber, text: text}
- switch typ {
- case itemCharConstant:
- rune, _, tail, err := strconv.UnquoteChar(text[1:], text[0])
- if err != nil {
- return nil, err
- }
- if tail != "'" {
- return nil, fmt.Errorf("malformed character constant: %s", text)
- }
- n.int64 = int64(rune)
- n.isInt = true
- n.uint64 = uint64(rune)
- n.isUint = true
- n.float64 = float64(rune) // odd but those are the rules.
- n.isFloat = true
- return n, nil
- case itemComplex:
- // fmt.Sscan can parse the pair, so let it do the work.
- if _, err := fmt.Sscan(text, &n.complex128); err != nil {
- return nil, err
- }
- n.isComplex = true
- n.simplifyComplex()
- return n, nil
- }
- // Imaginary constants can only be complex unless they are zero.
- if len(text) > 0 && text[len(text)-1] == 'i' {
- f, err := strconv.Atof64(text[:len(text)-1])
- if err == nil {
- n.isComplex = true
- n.complex128 = complex(0, f)
- n.simplifyComplex()
- return n, nil
- }
- }
- // Do integer test first so we get 0x123 etc.
- u, err := strconv.Btoui64(text, 0) // will fail for -0; fixed below.
- if err == nil {
- n.isUint = true
- n.uint64 = u
- }
- i, err := strconv.Btoi64(text, 0)
- if err == nil {
- n.isInt = true
- n.int64 = i
- if i == 0 {
- n.isUint = true // in case of -0.
- n.uint64 = u
- }
- }
- // If an integer extraction succeeded, promote the float.
- if n.isInt {
- n.isFloat = true
- n.float64 = float64(n.int64)
- } else if n.isUint {
- n.isFloat = true
- n.float64 = float64(n.uint64)
- } else {
- f, err := strconv.Atof64(text)
- if err == nil {
- n.isFloat = true
- n.float64 = f
- // If a floating-point extraction succeeded, extract the int if needed.
- if !n.isInt && float64(int64(f)) == f {
- n.isInt = true
- n.int64 = int64(f)
- }
- if !n.isUint && float64(uint64(f)) == f {
- n.isUint = true
- n.uint64 = uint64(f)
- }
- }
- }
- if !n.isInt && !n.isUint && !n.isFloat {
- return nil, fmt.Errorf("illegal number syntax: %q", text)
- }
- return n, nil
-}
-
-// simplifyComplex pulls out any other types that are represented by the complex number.
-// These all require that the imaginary part be zero.
-func (n *numberNode) simplifyComplex() {
- n.isFloat = imag(n.complex128) == 0
- if n.isFloat {
- n.float64 = real(n.complex128)
- n.isInt = float64(int64(n.float64)) == n.float64
- if n.isInt {
- n.int64 = int64(n.float64)
- }
- n.isUint = float64(uint64(n.float64)) == n.float64
- if n.isUint {
- n.uint64 = uint64(n.float64)
- }
- }
-}
-
-func (n *numberNode) String() string {
- return fmt.Sprintf("N=%s", n.text)
-}
-
-// stringNode holds a quoted string.
-type stringNode struct {
- nodeType
- text string
-}
-
-func newString(text string) *stringNode {
- return &stringNode{nodeType: nodeString, text: text}
-}
-
-func (s *stringNode) String() string {
- return fmt.Sprintf("S=%#q", s.text)
-}
-
-// endNode represents an {{end}} action. It is represented by a nil pointer.
-type endNode bool
-
-func newEnd() *endNode {
- return nil
-}
-
-func (e *endNode) typ() nodeType {
- return nodeEnd
-}
-
-func (e *endNode) String() string {
- return "{{end}}"
-}
-
-// elseNode represents an {{else}} action.
-type elseNode struct {
- nodeType
- line int
-}
-
-func newElse(line int) *elseNode {
- return &elseNode{nodeType: nodeElse, line: line}
-}
-
-func (e *elseNode) typ() nodeType {
- return nodeElse
-}
-
-func (e *elseNode) String() string {
- return "{{else}}"
-}
-// ifNode represents an {{if}} action and its commands.
-// TODO: what should evaluation look like? is a pipe enough?
-type ifNode struct {
- nodeType
- line int
- pipe *pipeNode
- list *listNode
- elseList *listNode
-}
-
-func newIf(line int, pipe *pipeNode, list, elseList *listNode) *ifNode {
- return &ifNode{nodeType: nodeIf, line: line, pipe: pipe, list: list, elseList: elseList}
-}
-
-func (i *ifNode) String() string {
- if i.elseList != nil {
- return fmt.Sprintf("({{if %s}} %s {{else}} %s)", i.pipe, i.list, i.elseList)
- }
- return fmt.Sprintf("({{if %s}} %s)", i.pipe, i.list)
-}
-
-// rangeNode represents a {{range}} action and its commands.
-type rangeNode struct {
- nodeType
- line int
- pipe *pipeNode
- list *listNode
- elseList *listNode
-}
-
-func newRange(line int, pipe *pipeNode, list, elseList *listNode) *rangeNode {
- return &rangeNode{nodeType: nodeRange, line: line, pipe: pipe, list: list, elseList: elseList}
-}
-
-func (r *rangeNode) String() string {
- if r.elseList != nil {
- return fmt.Sprintf("({{range %s}} %s {{else}} %s)", r.pipe, r.list, r.elseList)
- }
- return fmt.Sprintf("({{range %s}} %s)", r.pipe, r.list)
-}
-
-// templateNode represents a {{template}} action.
-type templateNode struct {
- nodeType
- line int
- name string
- pipe *pipeNode
-}
-
-func newTemplate(line int, name string, pipe *pipeNode) *templateNode {
- return &templateNode{nodeType: nodeTemplate, line: line, name: name, pipe: pipe}
-}
-
-func (t *templateNode) String() string {
- if t.pipe == nil {
- return fmt.Sprintf("{{template %q}}", t.name)
- }
- return fmt.Sprintf("{{template %q %s}}", t.name, t.pipe)
-}
-
-// withNode represents a {{with}} action and its commands.
-type withNode struct {
- nodeType
- line int
- pipe *pipeNode
- list *listNode
- elseList *listNode
-}
-
-func newWith(line int, pipe *pipeNode, list, elseList *listNode) *withNode {
- return &withNode{nodeType: nodeWith, line: line, pipe: pipe, list: list, elseList: elseList}
-}
-
-func (w *withNode) String() string {
- if w.elseList != nil {
- return fmt.Sprintf("({{with %s}} %s {{else}} %s)", w.pipe, w.list, w.elseList)
- }
- return fmt.Sprintf("({{with %s}} %s)", w.pipe, w.list)
+ return t.Tree.Name
}
// Parsing.
@@ -532,89 +42,13 @@
return t
}
-// errorf formats the error and terminates processing.
-func (t *Template) errorf(format string, args ...interface{}) {
- t.root = nil
- format = fmt.Sprintf("template: %s:%d: %s", t.name, t.lex.lineNumber(), format)
- panic(fmt.Errorf(format, args...))
-}
-
-// error terminates processing.
-func (t *Template) error(err os.Error) {
- t.errorf("%s", err)
-}
-
-// expect consumes the next token and guarantees it has the required type.
-func (t *Template) expect(expected itemType, context string) item {
- token := t.next()
- if token.typ != expected {
- t.errorf("expected %s in %s; got %s", expected, context, token)
- }
- return token
-}
-
-// unexpected complains about the token and terminates processing.
-func (t *Template) unexpected(token item, context string) {
- t.errorf("unexpected %s in %s", token, context)
-}
-
-// recover is the handler that turns panics into returns from the top
-// level of Parse or Execute.
-func (t *Template) recover(errp *os.Error) {
- e := recover()
- if e != nil {
- if _, ok := e.(runtime.Error); ok {
- panic(e)
- }
- t.stopParse()
- *errp = e.(os.Error)
- }
- return
-}
-
-// startParse starts the template parsing from the lexer.
-func (t *Template) startParse(set *Set, lex *lexer) {
- t.root = nil
- t.lex = lex
- t.vars = []string{"$"}
- t.parseSet = set
-}
-
-// stopParse terminates parsing.
-func (t *Template) stopParse() {
- t.lex = nil
- t.vars = nil
- t.parseSet = nil
-}
-
-// atEOF returns true if, possibly after spaces, we're at EOF.
-func (t *Template) atEOF() bool {
- for {
- token := t.peek()
- switch token.typ {
- case itemEOF:
- return true
- case itemText:
- for _, r := range token.val {
- if !unicode.IsSpace(r) {
- return false
- }
- }
- t.next() // skip spaces.
- continue
- }
- break
- }
- return false
-}
-
// Parse parses the template definition string to construct an internal
// representation of the template for execution.
func (t *Template) Parse(s string) (tmpl *Template, err os.Error) {
- defer t.recover(&err)
- t.startParse(t.set, lex(t.name, s))
- t.parse(true)
- t.stopParse()
+ t.Tree, err = parse.New(t.name).Parse(s, t.funcs, builtins)
+ if err != nil {
+ return nil, err
+ }
return t, nil
}
@@ -623,10 +57,14 @@
// to the set.
// Function bindings are checked against those in the set.
func (t *Template) ParseInSet(s string, set *Set) (tmpl *Template, err os.Error) {
- defer t.recover(&err)
- t.startParse(set, lex(t.name, s))
- t.parse(true)
- t.stopParse()
+ var setFuncs map[string]reflect.Value
+ if set != nil {
+ setFuncs = set.funcs
+ }
+ t.Tree, err = parse.New(t.name).Parse(s, t.funcs, setFuncs, builtins)
+ if err != nil {
+ return nil, err
+ }
t.addToSet(set)
return t, nil
}
@@ -639,271 +77,3 @@
// If double-assigned, Add will panic and we will turn that into an error.
set.Add(t)
}
-
-// parse is the helper for Parse.
-// It triggers an error if we expect EOF but don't reach it.
-func (t *Template) parse(toEOF bool) (next node) {
- t.root, next = t.itemList(true)
- if toEOF && next != nil {
- t.errorf("unexpected %s", next)
- }
- return next
-}
-
-// itemList:
-// textOrAction*
-// Terminates at EOF and at {{end}} or {{else}}, which is returned separately.
-// The toEOF flag tells whether we expect to reach EOF.
-func (t *Template) itemList(toEOF bool) (list *listNode, next node) {
- list = newList()
- for t.peek().typ != itemEOF {
- n := t.textOrAction()
- switch n.typ() {
- case nodeEnd, nodeElse:
- return list, n
- }
- list.append(n)
- }
- if !toEOF {
- t.unexpected(t.next(), "input")
- }
- return list, nil
-}
-
-// textOrAction:
-// text | action
-func (t *Template) textOrAction() node {
- switch token := t.next(); token.typ {
- case itemText:
- return newText(token.val)
- case itemLeftDelim:
- return t.action()
- default:
- t.unexpected(token, "input")
- }
- return nil
-}
-
-// Action:
-// control
-// command ("|" command)*
-// Left delim is past. Now get actions.
-// First word could be a keyword such as range.
-func (t *Template) action() (n node) {
- switch token := t.next(); token.typ {
- case itemElse:
- return t.elseControl()
- case itemEnd:
- return t.endControl()
- case itemIf:
- return t.ifControl()
- case itemRange:
- return t.rangeControl()
- case itemTemplate:
- return t.templateControl()
- case itemWith:
- return t.withControl()
- }
- t.backup()
- // Do not pop variables; they persist until "end".
- return newAction(t.lex.lineNumber(), t.pipeline("command"))
-}
-
-// Pipeline:
-// field or command
-// pipeline "|" pipeline
-func (t *Template) pipeline(context string) (pipe *pipeNode) {
- var decl []*variableNode
- // Are there declarations?
- for {
- if v := t.peek(); v.typ == itemVariable {
- t.next()
- if next := t.peek(); next.typ == itemColonEquals || next.typ == itemChar {
- t.next()
- variable := newVariable(v.val)
- if len(variable.ident) != 1 {
- t.errorf("illegal variable in declaration: %s", v.val)
- }
- decl = append(decl, variable)
- t.vars = append(t.vars, v.val)
- if next.typ == itemChar && next.val == "," {
- if context == "range" && len(decl) < 2 {
- continue
- }
- t.errorf("too many declarations in %s", context)
- }
- } else {
- t.backup2(v)
- }
- }
- break
- }
- pipe = newPipeline(t.lex.lineNumber(), decl)
- for {
- switch token := t.next(); token.typ {
- case itemRightDelim:
- if len(pipe.cmds) == 0 {
- t.errorf("missing value for %s", context)
- }
- return
- case itemBool, itemCharConstant, itemComplex, itemDot, itemField, itemIdentifier,
- itemVariable, itemNumber, itemRawString, itemString:
- t.backup()
- pipe.append(t.command())
- default:
- t.unexpected(token, context)
- }
- }
- return
-}
-
-func (t *Template) parseControl(context string) (lineNum int, pipe *pipeNode, list, elseList *listNode) {
- lineNum = t.lex.lineNumber()
- defer t.popVars(len(t.vars))
- pipe = t.pipeline(context)
- var next node
- list, next = t.itemList(false)
- switch next.typ() {
- case nodeEnd: //done
- case nodeElse:
- elseList, next = t.itemList(false)
- if next.typ() != nodeEnd {
- t.errorf("expected end; found %s", next)
- }
- elseList = elseList
- }
- return lineNum, pipe, list, elseList
-}
-
-// If:
-// {{if pipeline}} itemList {{end}}
-// {{if pipeline}} itemList {{else}} itemList {{end}}
-// If keyword is past.
-func (t *Template) ifControl() node {
- return newIf(t.parseControl("if"))
-}
-
-// Range:
-// {{range pipeline}} itemList {{end}}
-// {{range pipeline}} itemList {{else}} itemList {{end}}
-// Range keyword is past.
-func (t *Template) rangeControl() node {
- return newRange(t.parseControl("range"))
-}
-
-// With:
-// {{with pipeline}} itemList {{end}}
-// {{with pipeline}} itemList {{else}} itemList {{end}}
-// If keyword is past.
-func (t *Template) withControl() node {
- return newWith(t.parseControl("with"))
-}
-
-// End:
-// {{end}}
-// End keyword is past.
-func (t *Template) endControl() node {
- t.expect(itemRightDelim, "end")
- return newEnd()
-}
-
-// Else:
-// {{else}}
-// Else keyword is past.
-func (t *Template) elseControl() node {
- t.expect(itemRightDelim, "else")
- return newElse(t.lex.lineNumber())
-}
-
-// Template:
-// {{template stringValue pipeline}}
-// Template keyword is past. The name must be something that can evaluate
-// to a string.
-func (t *Template) templateControl() node {
- var name string
- switch token := t.next(); token.typ {
- case itemString, itemRawString:
- s, err := strconv.Unquote(token.val)
- if err != nil {
- t.error(err)
- }
- name = s
- default:
- t.unexpected(token, "template invocation")
- }
- var pipe *pipeNode
- if t.next().typ != itemRightDelim {
- t.backup()
- // Do not pop variables; they persist until "end".
- pipe = t.pipeline("template")
- }
- return newTemplate(t.lex.lineNumber(), name, pipe)
-}
-
-// command:
-// space-separated arguments up to a pipeline character or right delimiter.
-// we consume the pipe character but leave the right delim to terminate the action.
-func (t *Template) command() *commandNode {
- cmd := newCommand()
-Loop:
- for {
- switch token := t.next(); token.typ {
- case itemRightDelim:
- t.backup()
- break Loop
- case itemPipe:
- break Loop
- case itemError:
- t.errorf("%s", token.val)
- case itemIdentifier:
- if _, ok := findFunction(token.val, t, t.parseSet); !ok {
- t.errorf("function %q not defined", token.val)
- }
- cmd.append(newIdentifier(token.val))
- case itemDot:
- cmd.append(newDot())
- case itemVariable:
- cmd.append(t.useVar(token.val))
- case itemField:
- cmd.append(newField(token.val))
- case itemBool:
- cmd.append(newBool(token.val == "true"))
- case itemCharConstant, itemComplex, itemNumber:
- number, err := newNumber(token.val, token.typ)
- if err != nil {
- t.error(err)
- }
- cmd.append(number)
- case itemString, itemRawString:
- s, err := strconv.Unquote(token.val)
- if err != nil {
- t.error(err)
- }
- cmd.append(newString(s))
- default:
- t.unexpected(token, "command")
- }
- }
- if len(cmd.args) == 0 {
- t.errorf("empty command")
- }
- return cmd
-}
-
-// popVars trims the variable list to the specified length
-func (t *Template) popVars(n int) {
- t.vars = t.vars[:n]
-}
-
-// useVar returns a node for a variable reference. It errors if the
-// variable is not defined.
-func (t *Template) useVar(name string) node {
- v := newVariable(name)
- for _, varName := range t.vars {
- if varName == v.ident[0] {
- return v
- }
- }
- t.errorf("undefined variable %q", v.ident[0])
- return nil
-}
diff --git a/src/pkg/exp/template/parse/Makefile b/src/pkg/exp/template/parse/Makefile
new file mode 100644
index 0000000..5483a0c
--- /dev/null
+++ b/src/pkg/exp/template/parse/Makefile
@@ -0,0 +1,14 @@
+# Copyright 2011 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+include ../../../../Make.inc
+
+TARG=exp/template/parse
+GOFILES=\
+ lex.go\
+ node.go\
+ parse.go\
+ set.go\
+
+include ../../../../Make.pkg
diff --git a/src/pkg/exp/template/lex.go b/src/pkg/exp/template/parse/lex.go
similarity index 99%
rename from src/pkg/exp/template/lex.go
rename to src/pkg/exp/template/parse/lex.go
index 97f4e9d..7ec4e92 100644
--- a/src/pkg/exp/template/lex.go
+++ b/src/pkg/exp/template/parse/lex.go
@@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-package template
+package parse
import (
"fmt"
diff --git a/src/pkg/exp/template/lex_test.go b/src/pkg/exp/template/parse/lex_test.go
similarity index 99%
rename from src/pkg/exp/template/lex_test.go
rename to src/pkg/exp/template/parse/lex_test.go
index a585a41..2ad91d5 100644
--- a/src/pkg/exp/template/lex_test.go
+++ b/src/pkg/exp/template/parse/lex_test.go
@@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-package template
+package parse
import (
"reflect"
diff --git a/src/pkg/exp/template/parse/node.go b/src/pkg/exp/template/parse/node.go
new file mode 100644
index 0000000..0f77ad8
--- /dev/null
+++ b/src/pkg/exp/template/parse/node.go
@@ -0,0 +1,468 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Parse nodes.
+
+package parse
+
+import (
+ "bytes"
+ "fmt"
+ "os"
+ "strconv"
+ "strings"
+)
+
+// A node is an element in the parse tree. The interface is trivial.
+type Node interface {
+ Type() NodeType
+ String() string
+}
+
+// NodeType identifies the type of a parse tree node.
+type NodeType int
+
+// Type returns itself and provides an easy default implementation
+// for embedding in a Node. Embedded in all non-trivial Nodes.
+func (t NodeType) Type() NodeType {
+ return t
+}
+
+const (
+ NodeText NodeType = iota // Plain text.
+ NodeAction // An simple action such as field evaluation.
+ NodeBool // A boolean constant.
+ NodeCommand // An element of a pipeline.
+ NodeDot // The cursor, dot.
+ NodeElse // An else action.
+ NodeEnd // An end action.
+ NodeField // A field or method name.
+ NodeIdentifier // A identifier; always a function name.
+ NodeIf // An if action.
+ NodeList // A list of Nodes.
+ NodeNumber // A numerical constant.
+ NodePipe // A pipeline of commands.
+ NodeRange // A range action.
+ NodeString // A string constant.
+ NodeTemplate // A template invocation action.
+ NodeVariable // A $ variable.
+ NodeWith // A with action.
+)
+
+// Nodes.
+
+// ListNode holds a sequence of nodes.
+type ListNode struct {
+ NodeType
+ Nodes []Node // The element nodes in lexical order.
+}
+
+func newList() *ListNode {
+ return &ListNode{NodeType: NodeList}
+}
+
+func (l *ListNode) append(n Node) {
+ l.Nodes = append(l.Nodes, n)
+}
+
+func (l *ListNode) String() string {
+ b := new(bytes.Buffer)
+ fmt.Fprint(b, "[")
+ for _, n := range l.Nodes {
+ fmt.Fprint(b, n)
+ }
+ fmt.Fprint(b, "]")
+ return b.String()
+}
+
+// TextNode holds plain text.
+type TextNode struct {
+ NodeType
+ Text []byte // The text; may span newlines.
+}
+
+func newText(text string) *TextNode {
+ return &TextNode{NodeType: NodeText, Text: []byte(text)}
+}
+
+func (t *TextNode) String() string {
+ return fmt.Sprintf("(text: %q)", t.Text)
+}
+
+// PipeNode holds a pipeline with optional declaration
+type PipeNode struct {
+ NodeType
+ Line int // The line number in the input.
+ Decl []*VariableNode // Variable declarations in lexical order.
+ Cmds []*CommandNode // The commands in lexical order.
+}
+
+func newPipeline(line int, decl []*VariableNode) *PipeNode {
+ return &PipeNode{NodeType: NodePipe, Line: line, Decl: decl}
+}
+
+func (p *PipeNode) append(command *CommandNode) {
+ p.Cmds = append(p.Cmds, command)
+}
+
+func (p *PipeNode) String() string {
+ if p.Decl != nil {
+ return fmt.Sprintf("%v := %v", p.Decl, p.Cmds)
+ }
+ return fmt.Sprintf("%v", p.Cmds)
+}
+
+// ActionNode holds an action (something bounded by delimiters).
+// Control actions have their own nodes; ActionNode represents simple
+// ones such as field evaluations.
+type ActionNode struct {
+ NodeType
+ Line int // The line number in the input.
+ Pipe *PipeNode // The pipeline in the action.
+}
+
+func newAction(line int, pipe *PipeNode) *ActionNode {
+ return &ActionNode{NodeType: NodeAction, Line: line, Pipe: pipe}
+}
+
+func (a *ActionNode) String() string {
+ return fmt.Sprintf("(action: %v)", a.Pipe)
+}
+
+// CommandNode holds a command (a pipeline inside an evaluating action).
+type CommandNode struct {
+ NodeType
+ Args []Node // Arguments in lexical order: Identifier, field, or constant.
+}
+
+func newCommand() *CommandNode {
+ return &CommandNode{NodeType: NodeCommand}
+}
+
+func (c *CommandNode) append(arg Node) {
+ c.Args = append(c.Args, arg)
+}
+
+func (c *CommandNode) String() string {
+ return fmt.Sprintf("(command: %v)", c.Args)
+}
+
+// IdentifierNode holds an identifier.
+type IdentifierNode struct {
+ NodeType
+ Ident string // The identifier's name.
+}
+
+func newIdentifier(ident string) *IdentifierNode {
+ return &IdentifierNode{NodeType: NodeIdentifier, Ident: ident}
+}
+
+func (i *IdentifierNode) String() string {
+ return fmt.Sprintf("I=%s", i.Ident)
+}
+
+// VariableNode holds a list of variable names. The dollar sign is
+// part of the name.
+type VariableNode struct {
+ NodeType
+ Ident []string // Variable names in lexical order.
+}
+
+func newVariable(ident string) *VariableNode {
+ return &VariableNode{NodeType: NodeVariable, Ident: strings.Split(ident, ".")}
+}
+
+func (v *VariableNode) String() string {
+ return fmt.Sprintf("V=%s", v.Ident)
+}
+
+// DotNode holds the special identifier '.'. It is represented by a nil pointer.
+type DotNode bool
+
+func newDot() *DotNode {
+ return nil
+}
+
+func (d *DotNode) Type() NodeType {
+ return NodeDot
+}
+
+func (d *DotNode) String() string {
+ return "{{<.>}}"
+}
+
+// FieldNode holds a field (identifier starting with '.').
+// The names may be chained ('.x.y').
+// The period is dropped from each ident.
+type FieldNode struct {
+ NodeType
+ Ident []string // The identifiers in lexical order.
+}
+
+func newField(ident string) *FieldNode {
+ return &FieldNode{NodeType: NodeField, Ident: strings.Split(ident[1:], ".")} // [1:] to drop leading period
+}
+
+func (f *FieldNode) String() string {
+ return fmt.Sprintf("F=%s", f.Ident)
+}
+
+// BoolNode holds a boolean constant.
+type BoolNode struct {
+ NodeType
+ True bool // The value of the boolean constant.
+}
+
+func newBool(true bool) *BoolNode {
+ return &BoolNode{NodeType: NodeBool, True: true}
+}
+
+func (b *BoolNode) String() string {
+ return fmt.Sprintf("B=%t", b.True)
+}
+
+// NumberNode holds a number: signed or unsigned integer, float, or complex.
+// The value is parsed and stored under all the types that can represent the value.
+// This simulates in a small amount of code the behavior of Go's ideal constants.
+type NumberNode struct {
+ NodeType
+ IsInt bool // Number has an integral value.
+ IsUint bool // Number has an unsigned integral value.
+ IsFloat bool // Number has a floating-point value.
+ IsComplex bool // Number is complex.
+ Int64 int64 // The signed integer value.
+ Uint64 uint64 // The unsigned integer value.
+ Float64 float64 // The floating-point value.
+ Complex128 complex128 // The complex value.
+ Text string // The original textual representation from the input.
+}
+
+func newNumber(text string, typ itemType) (*NumberNode, os.Error) {
+ n := &NumberNode{NodeType: NodeNumber, Text: text}
+ switch typ {
+ case itemCharConstant:
+ rune, _, tail, err := strconv.UnquoteChar(text[1:], text[0])
+ if err != nil {
+ return nil, err
+ }
+ if tail != "'" {
+ return nil, fmt.Errorf("malformed character constant: %s", text)
+ }
+ n.Int64 = int64(rune)
+ n.IsInt = true
+ n.Uint64 = uint64(rune)
+ n.IsUint = true
+ n.Float64 = float64(rune) // odd but those are the rules.
+ n.IsFloat = true
+ return n, nil
+ case itemComplex:
+ // fmt.Sscan can parse the pair, so let it do the work.
+ if _, err := fmt.Sscan(text, &n.Complex128); err != nil {
+ return nil, err
+ }
+ n.IsComplex = true
+ n.simplifyComplex()
+ return n, nil
+ }
+ // Imaginary constants can only be complex unless they are zero.
+ if len(text) > 0 && text[len(text)-1] == 'i' {
+ f, err := strconv.Atof64(text[:len(text)-1])
+ if err == nil {
+ n.IsComplex = true
+ n.Complex128 = complex(0, f)
+ n.simplifyComplex()
+ return n, nil
+ }
+ }
+ // Do integer test first so we get 0x123 etc.
+ u, err := strconv.Btoui64(text, 0) // will fail for -0; fixed below.
+ if err == nil {
+ n.IsUint = true
+ n.Uint64 = u
+ }
+ i, err := strconv.Btoi64(text, 0)
+ if err == nil {
+ n.IsInt = true
+ n.Int64 = i
+ if i == 0 {
+ n.IsUint = true // in case of -0.
+ n.Uint64 = u
+ }
+ }
+ // If an integer extraction succeeded, promote the float.
+ if n.IsInt {
+ n.IsFloat = true
+ n.Float64 = float64(n.Int64)
+ } else if n.IsUint {
+ n.IsFloat = true
+ n.Float64 = float64(n.Uint64)
+ } else {
+ f, err := strconv.Atof64(text)
+ if err == nil {
+ n.IsFloat = true
+ n.Float64 = f
+ // If a floating-point extraction succeeded, extract the int if needed.
+ if !n.IsInt && float64(int64(f)) == f {
+ n.IsInt = true
+ n.Int64 = int64(f)
+ }
+ if !n.IsUint && float64(uint64(f)) == f {
+ n.IsUint = true
+ n.Uint64 = uint64(f)
+ }
+ }
+ }
+ if !n.IsInt && !n.IsUint && !n.IsFloat {
+ return nil, fmt.Errorf("illegal number syntax: %q", text)
+ }
+ return n, nil
+}
+
+// simplifyComplex pulls out any other types that are represented by the complex number.
+// These all require that the imaginary part be zero.
+func (n *NumberNode) simplifyComplex() {
+ n.IsFloat = imag(n.Complex128) == 0
+ if n.IsFloat {
+ n.Float64 = real(n.Complex128)
+ n.IsInt = float64(int64(n.Float64)) == n.Float64
+ if n.IsInt {
+ n.Int64 = int64(n.Float64)
+ }
+ n.IsUint = float64(uint64(n.Float64)) == n.Float64
+ if n.IsUint {
+ n.Uint64 = uint64(n.Float64)
+ }
+ }
+}
+
+func (n *NumberNode) String() string {
+ return fmt.Sprintf("N=%s", n.Text)
+}
+
+// StringNode holds a string constant. The value has been "unquoted".
+type StringNode struct {
+ NodeType
+ Quoted string // The original text of the string, with quotes.
+ Text string // The string, after quote processing.
+}
+
+func newString(orig, text string) *StringNode {
+ return &StringNode{NodeType: NodeString, Quoted: orig, Text: text}
+}
+
+func (s *StringNode) String() string {
+ return fmt.Sprintf("S=%#q", s.Text)
+}
+
+// EndNode represents an {{end}} action. It is represented by a nil pointer.
+type EndNode bool
+
+func newEnd() *EndNode {
+ return nil
+}
+
+func (e *EndNode) Type() NodeType {
+ return NodeEnd
+}
+
+func (e *EndNode) String() string {
+ return "{{end}}"
+}
+
+// ElseNode represents an {{else}} action.
+type ElseNode struct {
+ NodeType
+ Line int // The line number in the input.
+}
+
+func newElse(line int) *ElseNode {
+ return &ElseNode{NodeType: NodeElse, Line: line}
+}
+
+func (e *ElseNode) Type() NodeType {
+ return NodeElse
+}
+
+func (e *ElseNode) String() string {
+ return "{{else}}"
+}
+
+// IfNode represents an {{if}} action and its commands.
+type IfNode struct {
+ NodeType
+ Line int // The line number in the input.
+ Pipe *PipeNode // The pipeline to be evaluated.
+ List *ListNode // What to execute if the value is non-empty.
+ ElseList *ListNode // What to execute if the value is empty (nil if absent).
+}
+
+func newIf(line int, pipe *PipeNode, list, elseList *ListNode) *IfNode {
+ return &IfNode{NodeType: NodeIf, Line: line, Pipe: pipe, List: list, ElseList: elseList}
+}
+
+func (i *IfNode) String() string {
+ if i.ElseList != nil {
+ return fmt.Sprintf("({{if %s}} %s {{else}} %s)", i.Pipe, i.List, i.ElseList)
+ }
+ return fmt.Sprintf("({{if %s}} %s)", i.Pipe, i.List)
+}
+
+// RangeNode represents a {{range}} action and its commands.
+type RangeNode struct {
+ NodeType
+ Line int // The line number in the input.
+ Pipe *PipeNode // The pipeline to be evaluated.
+ List *ListNode // What to execute if the value is non-empty.
+ ElseList *ListNode // What to execute if the value is empty (nil if absent).
+}
+
+func newRange(line int, pipe *PipeNode, list, elseList *ListNode) *RangeNode {
+ return &RangeNode{NodeType: NodeRange, Line: line, Pipe: pipe, List: list, ElseList: elseList}
+}
+
+func (r *RangeNode) String() string {
+ if r.ElseList != nil {
+ return fmt.Sprintf("({{range %s}} %s {{else}} %s)", r.Pipe, r.List, r.ElseList)
+ }
+ return fmt.Sprintf("({{range %s}} %s)", r.Pipe, r.List)
+}
+
+// TemplateNode represents a {{template}} action.
+type TemplateNode struct {
+ NodeType
+ Line int // The line number in the input.
+ Name string // The name of the template (unquoted).
+ Pipe *PipeNode // The command to evaluate as dot for the template.
+}
+
+func newTemplate(line int, name string, pipe *PipeNode) *TemplateNode {
+ return &TemplateNode{NodeType: NodeTemplate, Line: line, Name: name, Pipe: pipe}
+}
+
+func (t *TemplateNode) String() string {
+ if t.Pipe == nil {
+ return fmt.Sprintf("{{template %q}}", t.Name)
+ }
+ return fmt.Sprintf("{{template %q %s}}", t.Name, t.Pipe)
+}
+
+// WithNode represents a {{with}} action and its commands.
+type WithNode struct {
+ NodeType
+ Line int // The line number in the input.
+ Pipe *PipeNode // The pipeline to be evaluated.
+ List *ListNode // What to execute if the value is non-empty.
+ ElseList *ListNode // What to execute if the value is empty (nil if absent).
+}
+
+func newWith(line int, pipe *PipeNode, list, elseList *ListNode) *WithNode {
+ return &WithNode{NodeType: NodeWith, Line: line, Pipe: pipe, List: list, ElseList: elseList}
+}
+
+func (w *WithNode) String() string {
+ if w.ElseList != nil {
+ return fmt.Sprintf("({{with %s}} %s {{else}} %s)", w.Pipe, w.List, w.ElseList)
+ }
+ return fmt.Sprintf("({{with %s}} %s)", w.Pipe, w.List)
+}
diff --git a/src/pkg/exp/template/parse/parse.go b/src/pkg/exp/template/parse/parse.go
new file mode 100644
index 0000000..2ee08da
--- /dev/null
+++ b/src/pkg/exp/template/parse/parse.go
@@ -0,0 +1,437 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package parse builds parse trees for templates. The grammar is defined
+// in the documents for the exp/template package.
+package parse
+
+import (
+ "fmt"
+ "os"
+ "reflect"
+ "runtime"
+ "strconv"
+ "unicode"
+)
+
+// Tree is the representation of a parsed template.
+type Tree struct {
+ Name string // Name is the name of the template.
+ Root *ListNode // Root is the top-level root of the parse tree.
+ // Parsing only; cleared after parse.
+ funcs []map[string]reflect.Value
+ lex *lexer
+ token [2]item // two-token lookahead for parser.
+ peekCount int
+ vars []string // variables defined at the moment.
+}
+
+// next returns the next token.
+func (t *Tree) next() item {
+ if t.peekCount > 0 {
+ t.peekCount--
+ } else {
+ t.token[0] = t.lex.nextItem()
+ }
+ return t.token[t.peekCount]
+}
+
+// backup backs the input stream up one token.
+func (t *Tree) backup() {
+ t.peekCount++
+}
+
+// backup2 backs the input stream up two tokens
+func (t *Tree) backup2(t1 item) {
+ t.token[1] = t1
+ t.peekCount = 2
+}
+
+// peek returns but does not consume the next token.
+func (t *Tree) peek() item {
+ if t.peekCount > 0 {
+ return t.token[t.peekCount-1]
+ }
+ t.peekCount = 1
+ t.token[0] = t.lex.nextItem()
+ return t.token[0]
+}
+
+// Parsing.
+
+// New allocates a new template with the given name.
+func New(name string, funcs ...map[string]reflect.Value) *Tree {
+ return &Tree{
+ Name: name,
+ funcs: funcs,
+ }
+}
+
+// errorf formats the error and terminates processing.
+func (t *Tree) errorf(format string, args ...interface{}) {
+ t.Root = nil
+ format = fmt.Sprintf("template: %s:%d: %s", t.Name, t.lex.lineNumber(), format)
+ panic(fmt.Errorf(format, args...))
+}
+
+// error terminates processing.
+func (t *Tree) error(err os.Error) {
+ t.errorf("%s", err)
+}
+
+// expect consumes the next token and guarantees it has the required type.
+func (t *Tree) expect(expected itemType, context string) item {
+ token := t.next()
+ if token.typ != expected {
+ t.errorf("expected %s in %s; got %s", expected, context, token)
+ }
+ return token
+}
+
+// unexpected complains about the token and terminates processing.
+func (t *Tree) unexpected(token item, context string) {
+ t.errorf("unexpected %s in %s", token, context)
+}
+
+// recover is the handler that turns panics into returns from the top level of Parse.
+func (t *Tree) recover(errp *os.Error) {
+ e := recover()
+ if e != nil {
+ if _, ok := e.(runtime.Error); ok {
+ panic(e)
+ }
+ if t != nil {
+ t.stopParse()
+ }
+ *errp = e.(os.Error)
+ }
+ return
+}
+
+// startParse starts the template parsing from the lexer.
+func (t *Tree) startParse(funcs []map[string]reflect.Value, lex *lexer) {
+ t.Root = nil
+ t.lex = lex
+ t.vars = []string{"$"}
+ t.funcs = funcs
+}
+
+// stopParse terminates parsing.
+func (t *Tree) stopParse() {
+ t.lex = nil
+ t.vars = nil
+ t.funcs = nil
+}
+
+// atEOF returns true if, possibly after spaces, we're at EOF.
+func (t *Tree) atEOF() bool {
+ for {
+ token := t.peek()
+ switch token.typ {
+ case itemEOF:
+ return true
+ case itemText:
+ for _, r := range token.val {
+ if !unicode.IsSpace(r) {
+ return false
+ }
+ }
+ t.next() // skip spaces.
+ continue
+ }
+ break
+ }
+ return false
+}
+
+// Parse parses the template definition string to construct an internal
+// representation of the template for execution.
+func (t *Tree) Parse(s string, funcs ...map[string]reflect.Value) (tree *Tree, err os.Error) {
+ defer t.recover(&err)
+ t.startParse(funcs, lex(t.Name, s))
+ t.parse(true)
+ t.stopParse()
+ return t, nil
+}
+
+// parse is the helper for Parse.
+// It triggers an error if we expect EOF but don't reach it.
+func (t *Tree) parse(toEOF bool) (next Node) {
+ t.Root, next = t.itemList(true)
+ if toEOF && next != nil {
+ t.errorf("unexpected %s", next)
+ }
+ return next
+}
+
+// itemList:
+// textOrAction*
+// Terminates at EOF and at {{end}} or {{else}}, which is returned separately.
+// The toEOF flag tells whether we expect to reach EOF.
+func (t *Tree) itemList(toEOF bool) (list *ListNode, next Node) {
+ list = newList()
+ for t.peek().typ != itemEOF {
+ n := t.textOrAction()
+ switch n.Type() {
+ case NodeEnd, NodeElse:
+ return list, n
+ }
+ list.append(n)
+ }
+ if !toEOF {
+ t.unexpected(t.next(), "input")
+ }
+ return list, nil
+}
+
+// textOrAction:
+// text | action
+func (t *Tree) textOrAction() Node {
+ switch token := t.next(); token.typ {
+ case itemText:
+ return newText(token.val)
+ case itemLeftDelim:
+ return t.action()
+ default:
+ t.unexpected(token, "input")
+ }
+ return nil
+}
+
+// Action:
+// control
+// command ("|" command)*
+// Left delim is past. Now get actions.
+// First word could be a keyword such as range.
+func (t *Tree) action() (n Node) {
+ switch token := t.next(); token.typ {
+ case itemElse:
+ return t.elseControl()
+ case itemEnd:
+ return t.endControl()
+ case itemIf:
+ return t.ifControl()
+ case itemRange:
+ return t.rangeControl()
+ case itemTemplate:
+ return t.templateControl()
+ case itemWith:
+ return t.withControl()
+ }
+ t.backup()
+ // Do not pop variables; they persist until "end".
+ return newAction(t.lex.lineNumber(), t.pipeline("command"))
+}
+
+// Pipeline:
+// field or command
+// pipeline "|" pipeline
+func (t *Tree) pipeline(context string) (pipe *PipeNode) {
+ var decl []*VariableNode
+ // Are there declarations?
+ for {
+ if v := t.peek(); v.typ == itemVariable {
+ t.next()
+ if next := t.peek(); next.typ == itemColonEquals || next.typ == itemChar {
+ t.next()
+ variable := newVariable(v.val)
+ if len(variable.Ident) != 1 {
+ t.errorf("illegal variable in declaration: %s", v.val)
+ }
+ decl = append(decl, variable)
+ t.vars = append(t.vars, v.val)
+ if next.typ == itemChar && next.val == "," {
+ if context == "range" && len(decl) < 2 {
+ continue
+ }
+ t.errorf("too many declarations in %s", context)
+ }
+ } else {
+ t.backup2(v)
+ }
+ }
+ break
+ }
+ pipe = newPipeline(t.lex.lineNumber(), decl)
+ for {
+ switch token := t.next(); token.typ {
+ case itemRightDelim:
+ if len(pipe.Cmds) == 0 {
+ t.errorf("missing value for %s", context)
+ }
+ return
+ case itemBool, itemCharConstant, itemComplex, itemDot, itemField, itemIdentifier,
+ itemVariable, itemNumber, itemRawString, itemString:
+ t.backup()
+ pipe.append(t.command())
+ default:
+ t.unexpected(token, context)
+ }
+ }
+ return
+}
+
+func (t *Tree) parseControl(context string) (lineNum int, pipe *PipeNode, list, elseList *ListNode) {
+ lineNum = t.lex.lineNumber()
+ defer t.popVars(len(t.vars))
+ pipe = t.pipeline(context)
+ var next Node
+ list, next = t.itemList(false)
+ switch next.Type() {
+ case NodeEnd: //done
+ case NodeElse:
+ elseList, next = t.itemList(false)
+ if next.Type() != NodeEnd {
+ t.errorf("expected end; found %s", next)
+ }
+ elseList = elseList
+ }
+ return lineNum, pipe, list, elseList
+}
+
+// If:
+// {{if pipeline}} itemList {{end}}
+// {{if pipeline}} itemList {{else}} itemList {{end}}
+// If keyword is past.
+func (t *Tree) ifControl() Node {
+ return newIf(t.parseControl("if"))
+}
+
+// Range:
+// {{range pipeline}} itemList {{end}}
+// {{range pipeline}} itemList {{else}} itemList {{end}}
+// Range keyword is past.
+func (t *Tree) rangeControl() Node {
+ return newRange(t.parseControl("range"))
+}
+
+// With:
+// {{with pipeline}} itemList {{end}}
+// {{with pipeline}} itemList {{else}} itemList {{end}}
+// If keyword is past.
+func (t *Tree) withControl() Node {
+ return newWith(t.parseControl("with"))
+}
+
+// End:
+// {{end}}
+// End keyword is past.
+func (t *Tree) endControl() Node {
+ t.expect(itemRightDelim, "end")
+ return newEnd()
+}
+
+// Else:
+// {{else}}
+// Else keyword is past.
+func (t *Tree) elseControl() Node {
+ t.expect(itemRightDelim, "else")
+ return newElse(t.lex.lineNumber())
+}
+
+// Template:
+// {{template stringValue pipeline}}
+// Template keyword is past. The name must be something that can evaluate
+// to a string.
+func (t *Tree) templateControl() Node {
+ var name string
+ switch token := t.next(); token.typ {
+ case itemString, itemRawString:
+ s, err := strconv.Unquote(token.val)
+ if err != nil {
+ t.error(err)
+ }
+ name = s
+ default:
+ t.unexpected(token, "template invocation")
+ }
+ var pipe *PipeNode
+ if t.next().typ != itemRightDelim {
+ t.backup()
+ // Do not pop variables; they persist until "end".
+ pipe = t.pipeline("template")
+ }
+ return newTemplate(t.lex.lineNumber(), name, pipe)
+}
+
+// command:
+// space-separated arguments up to a pipeline character or right delimiter.
+// we consume the pipe character but leave the right delim to terminate the action.
+func (t *Tree) command() *CommandNode {
+ cmd := newCommand()
+Loop:
+ for {
+ switch token := t.next(); token.typ {
+ case itemRightDelim:
+ t.backup()
+ break Loop
+ case itemPipe:
+ break Loop
+ case itemError:
+ t.errorf("%s", token.val)
+ case itemIdentifier:
+ if _, ok := t.findFunction(token.val); !ok {
+ t.errorf("function %q not defined", token.val)
+ }
+ cmd.append(newIdentifier(token.val))
+ case itemDot:
+ cmd.append(newDot())
+ case itemVariable:
+ cmd.append(t.useVar(token.val))
+ case itemField:
+ cmd.append(newField(token.val))
+ case itemBool:
+ cmd.append(newBool(token.val == "true"))
+ case itemCharConstant, itemComplex, itemNumber:
+ number, err := newNumber(token.val, token.typ)
+ if err != nil {
+ t.error(err)
+ }
+ cmd.append(number)
+ case itemString, itemRawString:
+ s, err := strconv.Unquote(token.val)
+ if err != nil {
+ t.error(err)
+ }
+ cmd.append(newString(token.val, s))
+ default:
+ t.unexpected(token, "command")
+ }
+ }
+ if len(cmd.Args) == 0 {
+ t.errorf("empty command")
+ }
+ return cmd
+}
+
+// findFunction looks for a function in the Tree's maps.
+func (t *Tree) findFunction(name string) (reflect.Value, bool) {
+ for _, funcMap := range t.funcs {
+ if funcMap == nil {
+ continue
+ }
+ if fn := funcMap[name]; fn.IsValid() {
+ return fn, true
+ }
+ }
+ return reflect.Value{}, false
+}
+
+// popVars trims the variable list to the specified length
+func (t *Tree) popVars(n int) {
+ t.vars = t.vars[:n]
+}
+
+// useVar returns a node for a variable reference. It errors if the
+// variable is not defined.
+func (t *Tree) useVar(name string) Node {
+ v := newVariable(name)
+ for _, varName := range t.vars {
+ if varName == v.Ident[0] {
+ return v
+ }
+ }
+ t.errorf("undefined variable %q", v.Ident[0])
+ return nil
+}
diff --git a/src/pkg/exp/template/parse_test.go b/src/pkg/exp/template/parse/parse_test.go
similarity index 89%
rename from src/pkg/exp/template/parse_test.go
rename to src/pkg/exp/template/parse/parse_test.go
index fb8956a..f57dab8 100644
--- a/src/pkg/exp/template/parse_test.go
+++ b/src/pkg/exp/template/parse/parse_test.go
@@ -2,11 +2,12 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-package template
+package parse
import (
"flag"
"fmt"
+ "reflect"
"testing"
)
@@ -100,47 +101,47 @@
}
continue
}
- if n.isComplex != test.isComplex {
+ if n.IsComplex != test.isComplex {
t.Errorf("complex incorrect for %q; should be %t", test.text, test.isComplex)
}
if test.isInt {
- if !n.isInt {
+ if !n.IsInt {
t.Errorf("expected integer for %q", test.text)
}
- if n.int64 != test.int64 {
- t.Errorf("int64 for %q should be %d is %d", test.text, test.int64, n.int64)
+ if n.Int64 != test.int64 {
+ t.Errorf("int64 for %q should be %d Is %d", test.text, test.int64, n.Int64)
}
- } else if n.isInt {
+ } else if n.IsInt {
t.Errorf("did not expect integer for %q", test.text)
}
if test.isUint {
- if !n.isUint {
+ if !n.IsUint {
t.Errorf("expected unsigned integer for %q", test.text)
}
- if n.uint64 != test.uint64 {
- t.Errorf("uint64 for %q should be %d is %d", test.text, test.uint64, n.uint64)
+ if n.Uint64 != test.uint64 {
+ t.Errorf("uint64 for %q should be %d Is %d", test.text, test.uint64, n.Uint64)
}
- } else if n.isUint {
+ } else if n.IsUint {
t.Errorf("did not expect unsigned integer for %q", test.text)
}
if test.isFloat {
- if !n.isFloat {
+ if !n.IsFloat {
t.Errorf("expected float for %q", test.text)
}
- if n.float64 != test.float64 {
- t.Errorf("float64 for %q should be %g is %g", test.text, test.float64, n.float64)
+ if n.Float64 != test.float64 {
+ t.Errorf("float64 for %q should be %g Is %g", test.text, test.float64, n.Float64)
}
- } else if n.isFloat {
+ } else if n.IsFloat {
t.Errorf("did not expect float for %q", test.text)
}
if test.isComplex {
- if !n.isComplex {
+ if !n.IsComplex {
t.Errorf("expected complex for %q", test.text)
}
- if n.complex128 != test.complex128 {
- t.Errorf("complex128 for %q should be %g is %g", test.text, test.complex128, n.complex128)
+ if n.Complex128 != test.complex128 {
+ t.Errorf("complex128 for %q should be %g Is %g", test.text, test.complex128, n.Complex128)
}
- } else if n.isComplex {
+ } else if n.IsComplex {
t.Errorf("did not expect complex for %q", test.text)
}
}
@@ -161,6 +162,8 @@
var parseTests = []parseTest{
{"empty", "", noError,
`[]`},
+ {"comment", "{{/*\n\n\n*/}}", noError,
+ `[]`},
{"spaces", " \t\n", noError,
`[(text: " \t\n")]`},
{"text", "some text", noError,
@@ -228,9 +231,13 @@
{"too many decls in range", "{{range $u, $v, $w := 3}}{{end}}", hasError, ""},
}
+var builtins = map[string]reflect.Value{
+ "printf": reflect.ValueOf(fmt.Sprintf),
+}
+
func TestParse(t *testing.T) {
for _, test := range parseTests {
- tmpl, err := New(test.name).Parse(test.input)
+ tmpl, err := New(test.name).Parse(test.input, builtins)
switch {
case err == nil && !test.ok:
t.Errorf("%q: expected error; got none", test.name)
@@ -245,7 +252,7 @@
}
continue
}
- result := tmpl.root.String()
+ result := tmpl.Root.String()
if result != test.result {
t.Errorf("%s=(%q): got\n\t%v\nexpected\n\t%v", test.name, test.input, result, test.result)
}
diff --git a/src/pkg/exp/template/parse/set.go b/src/pkg/exp/template/parse/set.go
new file mode 100644
index 0000000..91173d5
--- /dev/null
+++ b/src/pkg/exp/template/parse/set.go
@@ -0,0 +1,51 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package parse
+
+import (
+ "fmt"
+ "os"
+ "reflect"
+ "strconv"
+)
+
+// Set returns a slice of Trees created by parsing the template set
+// definition in the argument string. If an error is encountered,
+// parsing stops and an empty slice is returned with the error.
+func Set(text string, funcs ...map[string]reflect.Value) (tree map[string]*Tree, err os.Error) {
+ tree = make(map[string]*Tree)
+ defer (*Tree)(nil).recover(&err)
+ lex := lex("set", text)
+ const context = "define clause"
+ for {
+ t := New("set") // name will be updated once we know it.
+ t.startParse(funcs, lex)
+ // Expect EOF or "{{ define name }}".
+ if t.atEOF() {
+ break
+ }
+ t.expect(itemLeftDelim, context)
+ t.expect(itemDefine, context)
+ name := t.expect(itemString, context)
+ t.Name, err = strconv.Unquote(name.val)
+ if err != nil {
+ t.error(err)
+ }
+ t.expect(itemRightDelim, context)
+ end := t.parse(false)
+ if end == nil {
+ t.errorf("unexpected EOF in %s", context)
+ }
+ if end.Type() != NodeEnd {
+ t.errorf("unexpected %s in %s", end, context)
+ }
+ t.stopParse()
+ if _, present := tree[t.Name]; present {
+ return nil, fmt.Errorf("template: %q multiply defined", name)
+ }
+ tree[t.Name] = t
+ }
+ return
+}
diff --git a/src/pkg/exp/template/set.go b/src/pkg/exp/template/set.go
index 3e3197d..f6f2a2c 100644
--- a/src/pkg/exp/template/set.go
+++ b/src/pkg/exp/template/set.go
@@ -5,12 +5,11 @@
package template
import (
+ "exp/template/parse"
"fmt"
"io"
"os"
"reflect"
- "runtime"
- "strconv"
)
// Set holds a set of related templates that can refer to one another by name.
@@ -71,6 +70,11 @@
return s.tmpl[name]
}
+// FuncMap returns the set's function map.
+func (s *Set) FuncMap() map[string]reflect.Value {
+ return s.funcs
+}
+
// Execute applies the named template to the specified data object, writing
// the output to wr.
func (s *Set) Execute(wr io.Writer, name string, data interface{}) os.Error {
@@ -81,55 +85,21 @@
return tmpl.Execute(wr, data)
}
-// recover is the handler that turns panics into returns from the top
-// level of Parse.
-func (s *Set) recover(errp *os.Error) {
- e := recover()
- if e != nil {
- if _, ok := e.(runtime.Error); ok {
- panic(e)
- }
- s.tmpl = nil
- *errp = e.(os.Error)
- }
- return
-}
-
// Parse parses a string into a set of named templates. Parse may be called
// multiple times for a given set, adding the templates defined in the string
// to the set. If a template is redefined, the element in the set is
// overwritten with the new definition.
-func (s *Set) Parse(text string) (set *Set, err os.Error) {
- set = s
+func (s *Set) Parse(text string) (*Set, os.Error) {
+ trees, err := parse.Set(text, s.funcs, builtins)
+ if err != nil {
+ return nil, err
+ }
s.init()
- defer s.recover(&err)
- lex := lex("set", text)
- const context = "define clause"
- for {
- t := New("set") // name will be updated once we know it.
- t.startParse(s, lex)
- // Expect EOF or "{{ define name }}".
- if t.atEOF() {
- return nil, err
- }
- t.expect(itemLeftDelim, context)
- t.expect(itemDefine, context)
- name := t.expect(itemString, context)
- t.name, err = strconv.Unquote(name.val)
- if err != nil {
- t.error(err)
- }
- t.expect(itemRightDelim, context)
- end := t.parse(false)
- if end == nil {
- t.errorf("unexpected EOF in %s", context)
- }
- if end.typ() != nodeEnd {
- t.errorf("unexpected %s in %s", end, context)
- }
- t.stopParse()
- t.addToSet(s)
- s.tmpl[t.name] = t
+ for name, tree := range trees {
+ tmpl := New(name)
+ tmpl.Tree = tree
+ tmpl.addToSet(s)
+ s.tmpl[name] = tmpl
}
return s, nil
}
diff --git a/src/pkg/exp/template/set_test.go b/src/pkg/exp/template/set_test.go
index eef9342..6fa2906 100644
--- a/src/pkg/exp/template/set_test.go
+++ b/src/pkg/exp/template/set_test.go
@@ -9,6 +9,11 @@
"testing"
)
+const (
+ noError = true
+ hasError = false
+)
+
type setParseTest struct {
name string
input string
@@ -66,7 +71,7 @@
t.Errorf("%s: can't find template %q", test.name, name)
continue
}
- result := tmpl.root.String()
+ result := tmpl.Root.String()
if result != test.results[i] {
t.Errorf("%s=(%q): got\n\t%v\nexpected\n\t%v", test.name, test.input, result, test.results[i])
}
