This change includes some progress on actual compilation (albeit with several TODOs remaining before we can actually spit out a useful artifact). There are also some general cleanups sprinkled throughout. In a nutshell: * Add a compiler.Context object that will be available during template expansion. * Introduce a diag.Document abstraction. This is better than passing raw filenames around, and lets us embellish diagnostics as we go. In particular, we will be in a better position to provide line/column error information. * Move IO out of the Parser and into the Compiler, where it can cache and reuse Documents. This will become important as we start to load up dependencies. * Rename PosRange to Location. This reads nicer with the new Document terminology. * Rename the mu/api package to mu/schema. It's likely we will need to introduce a true AST that is decoupled from the serialization format and contains bound nodes. As a result, treating the existing types as "schema" is more honest. * Add in a big section of TODOs at the end of the compiler.Compiler.Build function.
77 lines
2.1 KiB
Go
77 lines
2.1 KiB
Go
// Copyright 2016 Marapongo, Inc. All rights reserved.
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package compiler
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import (
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"encoding/json"
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"github.com/ghodss/yaml"
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"github.com/golang/glog"
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"github.com/marapongo/mu/pkg/diag"
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"github.com/marapongo/mu/pkg/errors"
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"github.com/marapongo/mu/pkg/schema"
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)
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type Parser interface {
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// Diag fetches the diagnostics sink used by this parser.
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Diag() diag.Sink
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// Parse detects and parses input from the given path. If an error occurs, the return value will be nil. It is
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// expected that errors are conveyed using the diag.Sink interface.
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Parse(doc *diag.Document) *schema.Stack
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}
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func NewParser(c Compiler) Parser {
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return &parser{c}
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}
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type parser struct {
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c Compiler
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}
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func (p *parser) Diag() diag.Sink {
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return p.c.Diag()
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}
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func (p *parser) Parse(doc *diag.Document) *schema.Stack {
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glog.Infof("Parsing Mufile: %v (len(body)=%v)", doc.File, len(doc.Body))
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if glog.V(2) {
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defer func() {
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glog.V(2).Infof("Parsing Mufile '%v' completed w/ %v warnings and %v errors",
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doc.File, p.Diag().Warnings(), p.Diag().Errors())
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}()
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}
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// We support both JSON and YAML as a file format. Detect the file extension and deserialize the contents.
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// TODO: we need to expand templates as part of the parsing process.
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switch doc.Ext() {
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case ".json":
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return p.parseFromJSON(doc)
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case ".yaml":
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return p.parseFromYAML(doc)
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default:
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p.Diag().Errorf(errors.IllegalMufileExt.WithDocument(doc), doc.Ext())
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return nil
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}
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}
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func (p *parser) parseFromJSON(doc *diag.Document) *schema.Stack {
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var stack schema.Stack
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if err := json.Unmarshal(doc.Body, &stack); err != nil {
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p.Diag().Errorf(errors.IllegalMufileSyntax.WithDocument(doc), err)
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// TODO: it would be great if we issued an error per issue found in the file with line/col numbers.
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return nil
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}
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return &stack
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}
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func (p *parser) parseFromYAML(doc *diag.Document) *schema.Stack {
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var stack schema.Stack
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if err := yaml.Unmarshal(doc.Body, &stack); err != nil {
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p.Diag().Errorf(errors.IllegalMufileSyntax.WithDocument(doc), err)
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// TODO: it would be great if we issued an error per issue found in the file with line/col numbers.
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return nil
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}
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return &stack
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}
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