pulumi/pkg/compiler/parser.go
joeduffy 1302fc8a47 Add rudimentary template expansion
This change performs template expansion both for root stack documents in
addition to the transitive closure of dependencies.  There are many ongoing
design and implementation questions about how this should actually work;
please see marapongo/mu#7 for a discussion of them.
2016-11-25 12:58:29 -08:00

109 lines
4.3 KiB
Go

// Copyright 2016 Marapongo, Inc. All rights reserved.
package compiler
import (
"github.com/golang/glog"
"github.com/marapongo/mu/pkg/ast"
"github.com/marapongo/mu/pkg/compiler/core"
"github.com/marapongo/mu/pkg/diag"
"github.com/marapongo/mu/pkg/encoding"
"github.com/marapongo/mu/pkg/errors"
"github.com/marapongo/mu/pkg/util"
)
// Parse transforms a program's input text into a parse tree.
type Parser interface {
core.Phase
// ParseStack parses a Mufile from the given document. If an error occurs, the return value will be nil. It is
// expected that errors are conveyed using the diag.Sink interface.
ParseStack(doc *diag.Document, props ast.PropertyBag) *ast.Stack
// ParseWorkspace parses workspace settings from the given document. If an error occurs, the return value will be
// nil. It is expected that errors are conveyed using the diag.Sink interface.
ParseWorkspace(doc *diag.Document) *ast.Workspace
}
func NewParser(c Compiler) Parser {
return &parser{c}
}
type parser struct {
c Compiler
}
func (p *parser) Diag() diag.Sink {
return p.c.Diag()
}
func (p *parser) ParseWorkspace(doc *diag.Document) *ast.Workspace {
glog.Infof("Parsing workspace settings: %v (len(body)=%v)", doc.File, len(doc.Body))
if glog.V(2) {
defer func() {
glog.V(2).Infof("Parsing workspace settings '%v' completed w/ %v warnings and %v errors",
doc.File, p.Diag().Warnings(), p.Diag().Errors())
}()
}
// We support many file formats. Detect the file extension and deserialize the contents.
var w ast.Workspace
marshaler, has := encoding.Marshalers[doc.Ext()]
util.AssertMF(has, "No marshaler registered for this workspace extension: %v", doc.Ext())
if err := marshaler.Unmarshal(doc.Body, &w); err != nil {
p.Diag().Errorf(errors.ErrorIllegalWorkspaceSyntax.At(doc), err)
// TODO[marapongo/mu#14]: issue an error per issue found in the file with line/col numbers.
return nil
}
// Remember that this workspace came from this document.
w.Doc = doc
glog.V(3).Infof("Workspace settings %v parsed: %v clusters; %v deps",
doc.File, len(w.Clusters), len(w.Dependencies))
return &w
}
func (p *parser) ParseStack(doc *diag.Document, props ast.PropertyBag) *ast.Stack {
glog.Infof("Parsing Mufile: %v (len(body)=%v len(props)=%v)", doc.File, len(doc.Body), len(props))
if glog.V(2) {
defer func() {
glog.V(2).Infof("Parsing Mufile '%v' completed w/ %v warnings and %v errors",
doc.File, p.Diag().Warnings(), p.Diag().Errors())
}()
}
// Expand templates in the document first and foremost.
// TODO[marapongo/mu#7]: the order of template expansion is not clear. The way we've done it right now (i.e.,
// performing it right here), we haven't yet type-checked the properties supplied to the stack. As a result,
// there is less compile-time safety. And furthermore, the properties are in a map rather than being stored
// in structured types. In other words, this is really just a fancy pre-processor, rather than being well-
// integrated into the type system. To do that, however, we'd need to delay processing of templates, which
// itself will mess with our ability to parse the document. This is an area of future thinking.
// TODO[marapongo/mu#7]: related to this, certain information (like cluster target) isn't even available yet!
// TODO[marapongo/mu#14]: when we produce precise line/column errors, we'll need to somehow trace back to pre-
// template expansion, otherwise the numbers may not make sense to the user.
var err error
doc, err = RenderTemplates(doc, p.c.Context().WithProps(props))
if err != nil {
p.Diag().Errorf(errors.ErrorBadTemplate.At(doc), err)
return nil
}
// We support many file formats. Detect the file extension and deserialize the contents.
var stack ast.Stack
marshaler, has := encoding.Marshalers[doc.Ext()]
util.AssertMF(has, "No marshaler registered for this Mufile extension: %v", doc.Ext())
if err := marshaler.Unmarshal(doc.Body, &stack); err != nil {
p.Diag().Errorf(errors.ErrorIllegalMufileSyntax.At(doc), err)
// TODO[marapongo/mu#14]: issue an error per issue found in the file with line/col numbers.
return nil
}
// Remember that this stack came from this document.
stack.Doc = doc
glog.V(3).Infof("Mufile %v stack parsed: %v name; %v publics; %v privates",
doc.File, stack.Name, len(stack.Services.Public), len(stack.Services.Private))
return &stack
}