replace regex based directive scanner

This commit is contained in:
Gregor Lohaus
2026-05-24 16:00:48 +02:00
parent 0fab9c8d38
commit d8536d83de
7 changed files with 294 additions and 13 deletions

120
parser.ts
View File

@@ -9,12 +9,118 @@ export type TemplateVariable = {
const IF_RE = /<@(?:if|elseif)\((.+?)\)>/g
const VAR_RE = /<@var\(context\.(.+?)(?::(\w+))?\)>/g
const DIRECTIVE_RE = /<@(if|elseif|else|endif)(?:\((.+?)\))?>/g
const STRING_COMPARE_RE = /^(?:eq|neq)\(context\.(.+?),\s*"(.*)"\)$/
const PATH_RE = /^context\.(.+)$/
type DirectiveToken = {
type: "if" | "elseif" | "else" | "endif"
condition?: string
}
function readCondition(text: string, start: number): { condition: string; end: number } | null {
let depth = 0
let inString = false
let escaped = false
for (let i = start; i < text.length; i++) {
const char = text[i]!
if (escaped) {
escaped = false
continue
}
if (char === "\\") {
escaped = true
continue
}
if (char === "\"") {
inString = !inString
continue
}
if (inString) continue
if (char === "(") {
depth += 1
continue
}
if (char === ")") {
depth -= 1
if (depth === 0 && text[i + 1] === ">") {
return { condition: text.slice(start + 1, i), end: i + 2 }
}
}
}
return null
}
function getDirectiveTokens(text: string): DirectiveToken[] {
const tokens: DirectiveToken[] = []
for (let i = 0; i < text.length; i++) {
if (text[i] !== "<" || text[i + 1] !== "@") continue
const rest = text.slice(i + 2)
const type = ["elseif", "endif", "else", "if"].find(name => rest.startsWith(name)) as DirectiveToken["type"] | undefined
if (!type) continue
const afterName = i + 2 + type.length
if ((type === "if" || type === "elseif") && text[afterName] === "(") {
const parsed = readCondition(text, afterName)
if (!parsed) continue
tokens.push({ type, condition: parsed.condition })
i = parsed.end - 1
} else if ((type === "else" || type === "endif") && text[afterName] === ">") {
tokens.push({ type })
i = afterName
}
}
return tokens
}
function splitArgs(args: string): string[] {
const result: string[] = []
let current = ""
let depth = 0
let inString = false
let escaped = false
for (const char of args) {
if (escaped) {
current += char
escaped = false
continue
}
if (char === "\\") {
current += char
escaped = true
continue
}
if (char === "\"") {
current += char
inString = !inString
continue
}
if (!inString && char === "(") depth += 1
if (!inString && char === ")") depth -= 1
if (!inString && depth === 0 && char === ",") {
result.push(current.trim())
current = ""
continue
}
current += char
}
if (current.trim() !== "") result.push(current.trim())
return result
}
function extractCondition(expr: string | undefined, vars: TemplateVariable[]) {
if (!expr) throw new Error("Missing condition expression")
for (const operator of ["and", "or"]) {
const prefix = `${operator}(`
if (expr.startsWith(prefix) && expr.endsWith(")")) {
const args = splitArgs(expr.slice(prefix.length, -1))
if (args.length === 0) throw new Error(`Invalid condition expression: ${expr}`)
for (const arg of args) extractCondition(arg, vars)
return
}
}
const stringCompareMatch = expr.match(STRING_COMPARE_RE)
if (stringCompareMatch) {
vars.push({ path: stringCompareMatch[1]!, type: "string" })
@@ -29,8 +135,10 @@ function extractCondition(expr: string | undefined, vars: TemplateVariable[]) {
}
function extractFromString(text: string, vars: TemplateVariable[]) {
for (const match of text.matchAll(IF_RE)) {
extractCondition(match[1]!, vars)
for (const token of getDirectiveTokens(text)) {
if (token.type === "if" || token.type === "elseif") {
extractCondition(token.condition, vars)
}
}
for (const match of text.matchAll(VAR_RE)) {
vars.push({ path: match[1]!, type: match[2] ?? "string" })
@@ -40,9 +148,9 @@ function extractFromString(text: string, vars: TemplateVariable[]) {
function validateIfBlocks(content: string, vars: TemplateVariable[]) {
const stack: { sawElse: boolean }[] = []
for (const match of content.matchAll(DIRECTIVE_RE)) {
const directive = match[1]!
const condition = match[2]
for (const token of getDirectiveTokens(content)) {
const directive = token.type
const condition = token.condition
if (directive === "if") {
extractCondition(condition!, vars)