big tings

template/compile.go

@@ -0,0 +1,75 @@
+package template
+
+import (
+	"fmt"
+)
+
+// CompileTemplate scans once, emitting:
+// - data blocks: inner content between a line that's exactly "{" and a line that's exactly "}"
+// - matching blocks: gaps between data blocks (excluding the brace lines themselves)
+func CompileTemplate(template string) ([]Block, error) {
+	var out []Block
+	var curlyIndex int
+
+	const OPENING = '{'
+	const CLOSING = '}'
+
+	var start int
+	var blockType BlockType
+
+	if len(template) > 0 && template[0] == OPENING {
+		blockType = DataBlock
+	} else {
+		blockType = MatchingBlock
+	}
+
+	for i, r := range template {
+
+		nextCurlyIndex := curlyIndex
+
+		switch r {
+		case OPENING:
+			nextCurlyIndex++
+		case CLOSING:
+			nextCurlyIndex--
+		}
+
+		if curlyIndex == 0 && nextCurlyIndex == 1 {
+			if i > start {
+				block, err := ParseTemplateBlock(template[start:i], blockType)
+				if err != nil {
+					return nil, fmt.Errorf("cannot parse block: %w", err)
+				}
+				out = append(out, block)
+			}
+			start = i
+			blockType = DataBlock
+		} else if curlyIndex == 1 && nextCurlyIndex == 0 {
+
+			if i > start {
+				block, err := ParseTemplateBlock(template[start:i+1], blockType)
+				if err != nil {
+					return nil, fmt.Errorf("cannot parse block: %w", err)
+				}
+				out = append(out, block)
+			}
+
+			nextChar := ' '
+			if i+1 < len(template) {
+				nextChar = rune(template[i+1])
+			}
+
+			if nextChar == OPENING {
+				start = i + 1
+				blockType = DataBlock
+			} else {
+				start = i + 1
+				blockType = MatchingBlock
+			}
+		}
+
+		curlyIndex = nextCurlyIndex
+	}
+
+	return out, nil
+}