Writing spectra files with templates

test.j

NAME: meta.name
GUGUS: gaga
{%- if exists("meta.polarity") -%}POLARITY: {{ meta.polarity }}
{% endif -%}
{%- if exists("meta.antipolarity") -%}ANTIPOLARITY: {{ meta.antipolarity }}
{% endif -%}
{%- for key, value in meta.ms -%}
AC$MASS_SPECTROMETRY: {{key}} {{value}}
{% endfor -%}
Num Peaks: {{ length(peaks) }}
{%- for p in peaks -%}{{p.mz}} {{p.intensity}}{%- if not loop.is_last -%}, {%- endif -%}{%- endfor -%}

test.R

library(tidyverse)
library(jinjar)

template <- read_file("test.j")

meta <- list(
  name = "Specname",
  ms = list(collision = 33, ionization = "[M+H]+", sda="next"),
  polarity = "positive"
)

peaks <- tribble(
  ~ mz, ~ intensity,
  123.1234, 111,
  234.2345, 222,
  555.4321, 1
)

rendered <- template %>% render(meta = meta, peaks = peaks)
write_lines(rendered, "spectrum.txt")