TradingView Pine Script报错求助：第13行'sma = 0.0'匹配错误

报错核心原因 #

1. 自定义函数名sma和Pine Script内置的sma()函数重名，同时函数内的变量名也叫sma，引发命名冲突
2. 自定义函数的代码块未缩进，Pine Script要求函数体内容必须缩进（通常用4个空格）

修改后的完整代码 #

//@version=4
study("CLARITY ALGO FREE", overlay=true)
slow = input(21, title="Slow EMA")
//ema definitions
emaSlow = ema(close, slow)

// 自定义SMA函数，改名避免冲突，同时缩进函数体
custom_sma(src, length) =>
    custom_sma_val = 0.0
    custom_sma_val := na(custom_sma_val[1]) ? sum(src, length)/length : (custom_sma_val[1]*(length-1)+src)/length
    custom_sma_val

smaFast = custom_sma(close, 9)
//Color definition for Moving Averages
col = close > emaSlow ? color.lime : close < emaSlow ? color.red : color.yellow
//Moving Average Plots and Fill
p1 = plot(emaSlow, title="Slow MA", style=plot.style_linebr, linewidth=4, color=col)
p2 = plot(smaFast, title="Fast MA", style=plot.style_linebr, linewidth=2, color=col)
fill(p1, p2, color=col, transp=70)
plotshape(crossover(smaFast, emaSlow), style=shape.triangleup, size=size.tiny, color=color.green, text="Buy", title="Buy", location=location.belowbar)
plotshape(crossover(emaSlow, smaFast), style=shape.triangledown, size=size.tiny, color=color.red, text="Sell", title="Sell")
alertcondition(crossover(emaSlow, smaFast), title="Sell", message="Sell")
alertcondition(crossover(smaFast, emaSlow), title="Buy", message="Buy")

关键修改说明 #

• 将自定义函数名从sma改为custom_sma，避开内置函数的命名冲突
• 函数内的变量名改为custom_sma_val，避免和函数名重名
• 函数体的三行代码统一缩进4个空格，符合Pine Script的语法规范

内容的提问来源于stack exchange，提问作者Johnny