From fbc75bca57a3f66006468fb1a8f3988cdc8227d2 Mon Sep 17 00:00:00 2001
From: mryouse
Date: Wed, 7 Jun 2023 22:52:09 -0400
Subject: initial commit of branch

---
 parser.d | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

(limited to 'parser.d')

diff --git a/parser.d b/parser.d
index 004e1fb..0b31be8 100644
--- a/parser.d
+++ b/parser.d
@@ -17,6 +17,7 @@ enum FormType {
     DEF,
     BLOCK,
     IF,
+    BRANCH,
     AND,
     OR,
 
@@ -157,6 +158,20 @@ class If : Form {
 
 }
 
+class Branch : Form {
+
+    Form[] clauses;
+
+    this(int line) {
+        this.line = line;
+        this.type = FormType.BRANCH;
+    }
+
+    void addClause(Form clause) {
+        this.clauses ~= clause;
+    }
+}
+
 class And : Form {
 
     Form[] clauses;
@@ -605,6 +620,27 @@ class Parser {
         return if_;
     }
 
+    Form parseBranch() {
+        Branch branch = new Branch(-1);
+        Form f;
+        char next;
+        while(peekable()) {
+            next = peek();
+            if (next == ')') {
+                break;
+            }
+            branch.addClause(parseForm());
+        }
+
+        if (!peekable()) {
+            return new ParseError("unterminated branch", line);
+        }
+
+        advance();  // consume closing paren
+
+        return branch;
+    }
+
     Form parseAnd() {
         And and_ = new And(line);
         char next;
@@ -691,6 +727,8 @@ class Parser {
                     return parseBlock();
                 case "if":
                     return parseIf();
+                case "branch":
+                    return parseBranch();
                 case "and":
                     return parseAnd();
                 case "or":
-- 
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