Initial Commit

ast/ast.go

@@ -0,0 +1,160 @@
+/*
+   AMU: Custom simple markup language
+   Copyright (C) 2021 Arsen Musayelyan
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package ast
+
+import "fmt"
+
+// FormatType represents the type of
+// formatting to be done on a string
+type FormatType int
+
+const (
+	FormatTypeBold FormatType = iota
+	FormatTypeItalic
+	FormatTypeMath
+	FormatTypeCode
+	FormatTypeStrike
+)
+
+// AST is the root of the Abstract Syntax Tree for AMU
+type AST struct {
+	Entries []Entry
+}
+
+// Entry represents a single entry in the AST
+type Entry struct {
+	Heading *Heading
+	Image   *Image
+	List    *List
+	Code    *Code
+	Para    *Para
+	Break   *Break
+	Hline   *Hline
+}
+
+// Break represents a line break
+type Break struct{}
+
+// Hline represents a horizontal line
+type Hline struct{}
+
+// Heading represents a heading
+type Heading struct {
+	Level   int
+	Content *Para
+}
+
+// Image represents an image with alternate text
+// in case it fails to load and a clickable link
+type Image struct {
+	Alternate string
+	Source    string
+	Link      string
+}
+
+// List represents a list of items
+type List struct {
+	Type  string
+	Items []ListItem
+}
+
+// ListItem represents an item
+// with a level in a list
+type ListItem struct {
+	Level   int
+	Content []*Para
+}
+
+// Code represents source code to be
+// highlighted.
+type Code struct {
+	Language string
+	Style    string
+	Text     string
+}
+
+// Para represents a paragraph
+type Para struct {
+	Fragments []ParaFragment
+}
+
+// ParaFragment represents parts of
+// a paragraph which may or may not
+// be text
+type ParaFragment struct {
+	Word       *string
+	Whitespace *string
+	Punct      *string
+	Link       *Link
+	Format     *Format
+	Func       *Func
+}
+
+// Link represents a hyperlink
+type Link struct {
+	Link string
+	Text string
+}
+
+// Format represents formatted text
+type Format struct {
+	Types []FormatType
+	Text  string
+}
+
+// Func represents a function call
+type Func struct {
+	Name string
+	Args []string
+}
+
+// Funcs represents a place from which to retrieve
+// functions for calls
+type Funcs interface {
+	Set(string, func([]string) string)
+	Get(string) (func([]string) string, error)
+	Run(string, []string) string
+}
+
+// FuncMap is an implementation of Funcs using a map
+type FuncMap map[string]func([]string) string
+
+// Set adds a fucntion to the map
+func (fm FuncMap) Set(name string, fn func([]string) string) {
+	fm[name] = fn
+}
+
+// Get gets a function from the map
+func (fm FuncMap) Get(name string) (func([]string) string, error) {
+	// Get function
+	fn, ok := fm[name]
+	// If does not exist
+	if !ok {
+		// Return error
+		return nil, fmt.Errorf("func %s does not exist", name)
+	}
+	// Return function
+	return fn, nil
+}
+
+// Run runs a function in the map
+func (fm FuncMap) Run(name string, args []string) string {
+	// Return output of function
+	return fm[name](args)
+}