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path: root/src/lib/template/template.go
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Diffstat (limited to 'src/lib/template/template.go')
-rw-r--r--src/lib/template/template.go106
1 files changed, 45 insertions, 61 deletions
diff --git a/src/lib/template/template.go b/src/lib/template/template.go
index 327d8194b..36ff60937 100644
--- a/src/lib/template/template.go
+++ b/src/lib/template/template.go
@@ -66,19 +66,9 @@ import (
"template";
)
-// Errors returned during parsing and execution.
-var ErrUnmatchedRDelim = os.NewError("unmatched closing delimiter")
-var ErrUnmatchedLDelim = os.NewError("unmatched opening delimiter")
-var ErrBadDirective = os.NewError("unrecognized directive name")
-var ErrEmptyDirective = os.NewError("empty directive")
-var ErrFields = os.NewError("incorrect fields for directive")
-var ErrSyntax = os.NewError("directive out of place")
-var ErrNoEnd = os.NewError("section does not have .end")
-var ErrNoVar = os.NewError("variable name not in struct");
-var ErrBadType = os.NewError("unsupported type for variable");
-var ErrNotStruct = os.NewError("driver must be a struct")
-var ErrNoFormatter = os.NewError("unknown formatter")
-var ErrBadDelims = os.NewError("invalid delimiter strings")
+// Errors returned during parsing. TODO: different error model for execution?
+
+type ParseError struct { os.ErrorString }
// All the literals are aces.
var lbrace = []byte{ '{' }
@@ -112,15 +102,14 @@ var builtins = FormatterMap {
// State for executing a Template
type state struct {
parent *state; // parent in hierarchy
- errorchan chan *os.Error; // for erroring out
+ errorchan chan os.Error; // for erroring out
data reflect.Value; // the driver data for this section etc.
wr io.Write; // where to send output
}
// Report error and stop generation.
-func (st *state) error(err *os.Error, args ...) {
- fmt.Fprintf(os.Stderr, "template: %v%s\n", err, fmt.Sprint(args));
- st.errorchan <- err;
+func (st *state) parseError(line int, err string, args ...) {
+ st.errorchan <- ParseError{fmt.Sprintf("line %d: %s", line, fmt.Sprintf(err, args))};
sys.Goexit();
}
@@ -217,7 +206,7 @@ Loop:
i = j - 1;
case equal(t.buf, i, t.rdelim):
if !sawLeft {
- st.error(ErrUnmatchedRDelim)
+ st.parseError(*t.linenum, "unmatched closing delimiter")
}
sawLeft = false;
i += len(t.rdelim);
@@ -227,7 +216,7 @@ Loop:
}
}
if sawLeft {
- st.error(ErrUnmatchedLDelim)
+ st.parseError(*t.linenum, "unmatched opening delimiter")
}
item := t.buf[start:i];
if special && trim_white {
@@ -281,10 +270,10 @@ func (t *Template) analyze(item []byte, st *state) (tok int, w []string) {
return
}
if !equal(item, len(item)-len(t.rdelim), t.rdelim) { // doesn't end with right delimiter
- st.error(ErrUnmatchedLDelim) // should not happen anyway
+ st.parseError(*t.linenum, "unmatched opening delimiter") // should not happen anyway
}
if len(item) <= len(t.ldelim)+len(t.rdelim) { // no contents
- st.error(ErrEmptyDirective)
+ st.parseError(*t.linenum, "empty directive")
}
// Comment
if item[len(t.ldelim)] == '#' {
@@ -294,10 +283,7 @@ func (t *Template) analyze(item []byte, st *state) (tok int, w []string) {
// Split into words
w = words(item[len(t.ldelim): len(item)-len(t.rdelim)]); // drop final delimiter
if len(w) == 0 {
- st.error(ErrBadDirective)
- }
- if len(w[0]) == 0 {
- st.error(ErrEmptyDirective)
+ st.parseError(*t.linenum, "empty directive")
}
if len(w) == 1 && w[0][0] != '.' {
tok = Variable;
@@ -315,24 +301,24 @@ func (t *Template) analyze(item []byte, st *state) (tok int, w []string) {
return;
case ".section":
if len(w) != 2 {
- st.error(ErrFields, ": ", string(item))
+ st.parseError(*t.linenum, "incorrect fields for .section: %s", item)
}
tok = Section;
return;
case ".repeated":
if len(w) != 3 || w[1] != "section" {
- st.error(ErrFields, ": ", string(item))
+ st.parseError(*t.linenum, "incorrect fields for .repeated: %s", item)
}
tok = Repeated;
return;
case ".alternates":
if len(w) != 2 || w[1] != "with" {
- st.error(ErrFields, ": ", string(item))
+ st.parseError(*t.linenum, "incorrect fields for .alternates: %s", item)
}
tok = Alternates;
return;
}
- st.error(ErrBadDirective, ": ", string(item));
+ st.parseError(*t.linenum, "bad directive: %s", item);
return
}
@@ -375,18 +361,19 @@ func empty(v reflect.Value, indirect_ok bool) bool {
// Execute a ".repeated" section
func (t *Template) executeRepeated(w []string, st *state) {
if w[1] != "section" {
- st.error(ErrSyntax, `: .repeated must have "section"`)
+ st.parseError(*t.linenum, `.repeated must have "section"`)
}
// Find driver array/struct for this section. It must be in the current struct.
field := st.findVar(w[2]);
if field == nil {
- st.error(ErrNoVar, ": .repeated ", w[2], " in ", reflect.Indirect(st.data).Type());
+ st.parseError(*t.linenum, ".repeated: cannot find %s in %s", w[2], reflect.Indirect(st.data).Type());
}
+ field = reflect.Indirect(field);
// Must be an array/slice
if field != nil && field.Kind() != reflect.ArrayKind {
- st.error(ErrBadType, " in .repeated: ", w[2], " ", field.Type().String());
+ st.parseError(*t.linenum, ".repeated: %s has bad type %s", w[2], field.Type());
}
// Scan repeated section, remembering slice of text we must execute.
nesting := 0;
@@ -396,7 +383,7 @@ Loop:
for {
item := t.nextItem(st);
if len(item) == 0 {
- st.error(ErrNoEnd)
+ st.parseError(*t.linenum, "missing .end")
}
tok, s := t.analyze(item, st);
switch tok {
@@ -430,7 +417,7 @@ func (t *Template) executeSection(w []string, st *state) {
// Find driver data for this section. It must be in the current struct.
field := st.findVar(w[1]);
if field == nil {
- st.error(ErrNoVar, ": .section ", w[1], " in ", reflect.Indirect(st.data).Type());
+ st.parseError(*t.linenum, ".section: cannot find %s in %s", w[1], reflect.Indirect(st.data).Type());
}
// Scan section, remembering slice of text we must execute.
orFound := false;
@@ -442,7 +429,7 @@ Loop:
for {
item := t.nextItem(st);
if len(item) == 0 {
- st.error(ErrNoEnd)
+ st.parseError(*t.linenum, "missing .end")
}
tok, s := t.analyze(item, st);
switch tok {
@@ -458,7 +445,7 @@ Loop:
break
}
if orFound {
- st.error(ErrSyntax, ": .or");
+ st.parseError(*t.linenum, "unexpected .or");
}
orFound = true;
if !accumulate {
@@ -491,7 +478,7 @@ func (t *Template) varValue(name string, st *state) reflect.Value {
field := st.findVar(name);
if field == nil {
if st.parent == nil {
- st.error(ErrNoVar, ": ", name)
+ st.parseError(*t.linenum, "name not found: %s", name)
}
return t.varValue(name, st.parent);
}
@@ -521,7 +508,7 @@ func (t *Template) writeVariable(st *state, name_formatter string) {
fn(st.wr, val, formatter);
return;
}
- st.error(ErrNoFormatter, ": ", formatter);
+ st.parseError(*t.linenum, "unknown formatter: %s", formatter);
panic("notreached");
}
@@ -553,7 +540,7 @@ func (t *Template) execute(st *state) {
case Variable:
t.writeVariable(st, w[0]);
case Or, End, Alternates:
- st.error(ErrSyntax, ": ", string(item));
+ st.parseError(*t.linenum, "unexpected %s", w[0]);
case Section:
t.executeSection(w, st);
case Repeated:
@@ -568,7 +555,7 @@ func (t *Template) doParse() {
// stub for now
}
-// A valid delimeter must contain no white space and be non-empty.
+// A valid delimiter must contain no white space and be non-empty.
func validDelim(d []byte) bool {
if len(d) == 0 {
return false
@@ -581,32 +568,29 @@ func validDelim(d []byte) bool {
return true;
}
-// Parse initializes a Template by parsing its definition. The string s contains
-// the template text. If any errors occur, it returns the error and line number
-// in the text of the erroneous construct.
-func (t *Template) Parse(s string) (err *os.Error, eline int) {
+// Parse initializes a Template by parsing its definition. The string
+// s contains the template text. If any errors occur, Parse returns
+// the error.
+func (t *Template) Parse(s string) (err os.Error) {
if !validDelim(t.ldelim) || !validDelim(t.rdelim) {
- return ErrBadDelims, 0
+ return ParseError{fmt.Sprintf("bad delimiter strings %q %q", t.ldelim, t.rdelim)}
}
t.init(io.StringBytes(s));
- ch := make(chan *os.Error);
+ ch := make(chan os.Error);
go func() {
t.doParse();
ch <- nil; // clean return;
}();
err = <-ch;
- if err != nil {
- return err, *t.linenum
- }
return
}
// Execute executes a parsed template on the specified data object,
// generating output to wr.
-func (t *Template) Execute(data interface{}, wr io.Write) *os.Error {
+func (t *Template) Execute(data interface{}, wr io.Write) os.Error {
// Extract the driver data.
val := reflect.NewValue(data);
- ch := make(chan *os.Error);
+ ch := make(chan os.Error);
go func() {
t.p = 0;
t.execute(&state{nil, ch, val, wr});
@@ -625,23 +609,23 @@ func New(fmap FormatterMap) *Template {
return t;
}
-// SetDelims sets the left and right delimiters for operations in the template.
-// They are validated during parsing. They could be validated here but it's
-// better to keep the routine simple. The delimiters are very rarely invalid
-// and Parse has the necessary error-handling interface already.
+// SetDelims sets the left and right delimiters for operations in the
+// template. They are validated during parsing. They could be
+// validated here but it's better to keep the routine simple. The
+// delimiters are very rarely invalid and Parse has the necessary
+// error-handling interface already.
func (t *Template) SetDelims(left, right string) {
t.ldelim = io.StringBytes(left);
t.rdelim = io.StringBytes(right);
}
// Parse creates a Template with default parameters (such as {} for
-// metacharacters). The string s contains the template text while the
-// formatter map fmap, which may be nil, defines auxiliary functions
+// metacharacters). The string s contains the template text while
+// the formatter map fmap, which may be nil, defines auxiliary functions
// for formatting variables. The template is returned. If any errors
-// occur, err will be non-nil and eline will be the line number in the
-// text of the erroneous construct.
-func Parse(s string, fmap FormatterMap) (t *Template, err *os.Error, eline int) {
+// occur, err will be non-nil.
+func Parse(s string, fmap FormatterMap) (t *Template, err os.Error) {
t = New(fmap);
- err, eline = t.Parse(s);
+ err = t.Parse(s);
return
}
generated by cgit v1.2.3 (git 2.46.0) at 2025-10-30 05:56:30 +0000