From 4eac5c67aa471a624d400eae8b0668d869624bf8 Mon Sep 17 00:00:00 2001
From: Sasha Koshka <sashakoshka@tebibyte.media>
Date: Tue, 23 Aug 2022 15:13:00 -0400
Subject: [PATCH] Added untested interface section parsing

---
 parser/face.go | 130 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 130 insertions(+)
 create mode 100644 parser/face.go

diff --git a/parser/face.go b/parser/face.go
new file mode 100644
index 0000000..a6b96eb
--- /dev/null
+++ b/parser/face.go
@@ -0,0 +1,130 @@
+package parser
+
+import "git.tebibyte.media/sashakoshka/arf/types"
+import "git.tebibyte.media/sashakoshka/arf/lexer"
+import "git.tebibyte.media/sashakoshka/arf/infoerr"
+
+// parseFaceSection parses an interface section.
+func (parser *ParsingOperation) parseFaceSection () (
+	section *FaceSection,
+	err     error,
+) {
+	err = parser.expect(lexer.TokenKindName)
+	if err != nil { return }
+	
+	section = &FaceSection {
+		location: parser.token.Location(),
+		behaviors:  make(map[string] FaceBehavior),
+	}
+
+	// get permission
+	err = parser.nextToken(lexer.TokenKindPermission)
+	if err != nil { return }
+	section.permission = parser.token.Value().(types.Permission)
+
+	// get name
+	err = parser.nextToken(lexer.TokenKindName)
+	if err != nil { return }
+	section.name = parser.token.Value().(string)
+
+	// parse inherited interface
+	err = parser.nextToken(lexer.TokenKindColon)
+	if err != nil { return }
+	err = parser.nextToken(lexer.TokenKindName)
+	if err != nil { return }
+	section.inherits = parser.token.Value().(string)
+	if err != nil { return }
+	err = parser.expect(lexer.TokenKindNewline)
+	if err != nil { return }
+	err = parser.nextToken()
+	if err != nil { return }
+
+	// parse members
+	for {
+		// if we've left the block, stop parsing
+		if !parser.token.Is(lexer.TokenKindIndent) { return }
+		if parser.token.Value().(int) != 1         { return }
+
+		// parse behavior
+		err = parser.nextToken(lexer.TokenKindName)
+		if err != nil { return }
+		behaviorBeginning := parser.token.Location()
+		var behavior FaceBehavior
+		behavior, err = parser.parseFaceBehavior()
+
+		// add to section
+		_, exists := section.behaviors[behavior.name]
+		if exists {
+			err = infoerr.NewError (
+				behaviorBeginning,
+				"multiple behaviors named " + behavior.name +
+				" in this interface",
+				infoerr.ErrorKindError)
+			return
+		}
+		
+		if err != nil { return }
+	}
+	return
+}
+
+// parseFaceBehavior parses a single interface behavior. Indentation level is
+// assumed.
+func (parser *ParsingOperation) parseFaceBehavior () (
+	behavior FaceBehavior,
+	err      error,
+) {
+	// get name
+	err = parser.nextToken(lexer.TokenKindName)
+	if err != nil { return }
+	behavior.name = parser.token.Value().(string)
+
+	for {
+		err = parser.nextToken(lexer.TokenKindNewline)
+		if err != nil { return }
+		
+		// if we've left the block, stop parsing
+		err = parser.nextToken()
+		if err != nil { return }
+		if !parser.token.Is(lexer.TokenKindIndent) { return }
+		if parser.token.Value().(int) != 2         { return }
+
+		// get preceding symbol
+		err = parser.nextToken (
+			lexer.TokenKindGreaterThan,
+			lexer.TokenKindLessThan)
+		if err != nil { return }
+		kind := parser.token.Kind()
+
+		var declaration Declaration
+
+		// get name
+		err = parser.nextToken(lexer.TokenKindName)
+		if err != nil { return }
+		declaration.name = parser.token.Value().(string)
+
+		// parse inherited type
+		err = parser.nextToken(lexer.TokenKindColon)
+		if err != nil { return }
+		err = parser.nextToken()
+		if err != nil { return }
+		declaration.what, err = parser.parseType()
+		if err != nil { return }
+		err = parser.expect(lexer.TokenKindNewline)
+		if err != nil { return }
+		err = parser.nextToken()
+		if err != nil { return }
+
+		if kind == lexer.TokenKindGreaterThan {
+			behavior.inputs = append (
+				behavior.inputs,
+				declaration)
+		} else {
+			behavior.inputs = append (
+				behavior.inputs,
+				declaration)
+		}
+	}
+	
+	return
+}